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NetBSD/sys/netinet6/nd6_rtr.c

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/* $NetBSD: nd6_rtr.c,v 1.47 2003/12/10 11:46:33 itojun Exp $ */
/* $KAME: nd6_rtr.c,v 1.95 2001/02/07 08:09:47 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_rtr.c,v 1.47 2003/12/10 11:46:33 itojun Exp $");
#include <sys/param.h>
#include <sys/systm.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/errno.h>
#include <sys/ioctl.h>
#include <sys/syslog.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <net/radix.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 <net/net_osdep.h>
#define SDL(s) ((struct sockaddr_dl *)s)
static int rtpref __P((struct nd_defrouter *));
static struct nd_defrouter *defrtrlist_update __P((struct nd_defrouter *));
static struct in6_ifaddr *in6_ifadd __P((struct nd_prefix *));
static struct nd_pfxrouter *pfxrtr_lookup __P((struct nd_prefix *,
struct nd_defrouter *));
static void pfxrtr_add __P((struct nd_prefix *, struct nd_defrouter *));
static void pfxrtr_del __P((struct nd_pfxrouter *));
static struct nd_pfxrouter *find_pfxlist_reachable_router
__P((struct nd_prefix *));
static void defrouter_delreq __P((struct nd_defrouter *));
static void defrouter_addifreq __P((struct ifnet *));
static void defrouter_delifreq __P((void));
static void nd6_rtmsg __P((int, struct rtentry *));
static void in6_init_address_ltimes __P((struct nd_prefix *ndpr,
struct in6_addrlifetime *lt6));
static int rt6_deleteroute __P((struct radix_node *, void *));
extern int nd6_recalc_reachtm_interval;
static struct ifnet *nd6_defifp;
int nd6_defifindex;
static struct ifaddr *nd6_defif_installed = NULL;
/*
* Receive Router Solicitation Message - just for routers.
* Router solicitation/advertisement is mostly managed by userland program
* (rtadvd) so here we have no function like nd6_ra_output().
*
* Based on RFC 2461
*/
void
nd6_rs_input(m, off, icmp6len)
struct mbuf *m;
int off, icmp6len;
{
struct ifnet *ifp = m->m_pkthdr.rcvif;
struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
struct nd_router_solicit *nd_rs;
struct in6_addr saddr6 = ip6->ip6_src;
#if 0
struct in6_addr daddr6 = ip6->ip6_dst;
#endif
char *lladdr = NULL;
int lladdrlen = 0;
#if 0
struct sockaddr_dl *sdl = (struct sockaddr_dl *)NULL;
struct llinfo_nd6 *ln = (struct llinfo_nd6 *)NULL;
struct rtentry *rt = NULL;
int is_newentry;
#endif
union nd_opts ndopts;
/* If I'm not a router, ignore it. */
if (ip6_accept_rtadv != 0 || !ip6_forwarding)
goto freeit;
/* Sanity checks */
if (ip6->ip6_hlim != 255) {
nd6log((LOG_ERR,
"nd6_rs_input: invalid hlim (%d) from %s to %s on %s\n",
ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
ip6_sprintf(&ip6->ip6_dst), if_name(ifp)));
goto bad;
}
/*
* Don't update the neighbor cache, if src = ::.
* This indicates that the src has no IP address assigned yet.
*/
if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
goto freeit;
IP6_EXTHDR_GET(nd_rs, struct nd_router_solicit *, m, off, icmp6len);
if (nd_rs == NULL) {
icmp6stat.icp6s_tooshort++;
return;
}
icmp6len -= sizeof(*nd_rs);
nd6_option_init(nd_rs + 1, icmp6len, &ndopts);
if (nd6_options(&ndopts) < 0) {
nd6log((LOG_INFO,
"nd6_rs_input: invalid ND option, ignored\n"));
/* nd6_options have incremented stats */
goto freeit;
}
if (ndopts.nd_opts_src_lladdr) {
lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
}
if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
nd6log((LOG_INFO,
"nd6_rs_input: lladdrlen mismatch for %s "
"(if %d, RS packet %d)\n",
ip6_sprintf(&saddr6), ifp->if_addrlen, lladdrlen - 2));
goto bad;
}
nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_SOLICIT, 0);
freeit:
m_freem(m);
return;
bad:
icmp6stat.icp6s_badrs++;
m_freem(m);
}
/*
* Receive Router Advertisement Message.
*
* Based on RFC 2461
* TODO: on-link bit on prefix information
* TODO: ND_RA_FLAG_{OTHER,MANAGED} processing
*/
void
nd6_ra_input(m, off, icmp6len)
struct mbuf *m;
int off, icmp6len;
{
struct ifnet *ifp = m->m_pkthdr.rcvif;
struct nd_ifinfo *ndi = ND_IFINFO(ifp);
struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
struct nd_router_advert *nd_ra;
struct in6_addr saddr6 = ip6->ip6_src;
#if 0
struct in6_addr daddr6 = ip6->ip6_dst;
int flags; /* = nd_ra->nd_ra_flags_reserved; */
int is_managed = ((flags & ND_RA_FLAG_MANAGED) != 0);
int is_other = ((flags & ND_RA_FLAG_OTHER) != 0);
#endif
union nd_opts ndopts;
struct nd_defrouter *dr;
/*
* We only accept RAs only when
* the system-wide variable allows the acceptance, and
* per-interface variable allows RAs on the receiving interface.
*/
if (ip6_accept_rtadv == 0)
goto freeit;
if (!(ndi->flags & ND6_IFF_ACCEPT_RTADV))
goto freeit;
if (ip6->ip6_hlim != 255) {
nd6log((LOG_ERR,
"nd6_ra_input: invalid hlim (%d) from %s to %s on %s\n",
ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
ip6_sprintf(&ip6->ip6_dst), if_name(ifp)));
goto bad;
}
if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) {
nd6log((LOG_ERR,
"nd6_ra_input: src %s is not link-local\n",
ip6_sprintf(&saddr6)));
goto bad;
}
IP6_EXTHDR_GET(nd_ra, struct nd_router_advert *, m, off, icmp6len);
if (nd_ra == NULL) {
icmp6stat.icp6s_tooshort++;
return;
}
icmp6len -= sizeof(*nd_ra);
nd6_option_init(nd_ra + 1, icmp6len, &ndopts);
if (nd6_options(&ndopts) < 0) {
nd6log((LOG_INFO,
"nd6_ra_input: invalid ND option, ignored\n"));
/* nd6_options have incremented stats */
goto freeit;
}
{
struct nd_defrouter dr0;
u_int32_t advreachable = nd_ra->nd_ra_reachable;
Bzero(&dr0, sizeof(dr0));
dr0.rtaddr = saddr6;
dr0.flags = nd_ra->nd_ra_flags_reserved;
dr0.rtlifetime = ntohs(nd_ra->nd_ra_router_lifetime);
dr0.expire = time.tv_sec + dr0.rtlifetime;
dr0.ifp = ifp;
/* unspecified or not? (RFC 2461 6.3.4) */
if (advreachable) {
NTOHL(advreachable);
if (advreachable <= MAX_REACHABLE_TIME &&
ndi->basereachable != advreachable) {
ndi->basereachable = advreachable;
ndi->reachable = ND_COMPUTE_RTIME(ndi->basereachable);
ndi->recalctm = nd6_recalc_reachtm_interval; /* reset */
}
}
if (nd_ra->nd_ra_retransmit)
ndi->retrans = ntohl(nd_ra->nd_ra_retransmit);
if (nd_ra->nd_ra_curhoplimit)
ndi->chlim = nd_ra->nd_ra_curhoplimit;
dr = defrtrlist_update(&dr0);
}
/*
* prefix
*/
if (ndopts.nd_opts_pi) {
struct nd_opt_hdr *pt;
struct nd_opt_prefix_info *pi = NULL;
struct nd_prefix pr;
for (pt = (struct nd_opt_hdr *)ndopts.nd_opts_pi;
pt <= (struct nd_opt_hdr *)ndopts.nd_opts_pi_end;
pt = (struct nd_opt_hdr *)((caddr_t)pt +
(pt->nd_opt_len << 3))) {
if (pt->nd_opt_type != ND_OPT_PREFIX_INFORMATION)
continue;
pi = (struct nd_opt_prefix_info *)pt;
if (pi->nd_opt_pi_len != 4) {
nd6log((LOG_INFO,
"nd6_ra_input: invalid option "
"len %d for prefix information option, "
"ignored\n", pi->nd_opt_pi_len));
continue;
}
if (128 < pi->nd_opt_pi_prefix_len) {
nd6log((LOG_INFO,
"nd6_ra_input: invalid prefix "
"len %d for prefix information option, "
"ignored\n", pi->nd_opt_pi_prefix_len));
continue;
}
if (IN6_IS_ADDR_MULTICAST(&pi->nd_opt_pi_prefix)
|| IN6_IS_ADDR_LINKLOCAL(&pi->nd_opt_pi_prefix)) {
nd6log((LOG_INFO,
"nd6_ra_input: invalid prefix "
"%s, ignored\n",
ip6_sprintf(&pi->nd_opt_pi_prefix)));
continue;
}
/* aggregatable unicast address, rfc2374 */
if ((pi->nd_opt_pi_prefix.s6_addr8[0] & 0xe0) == 0x20
&& pi->nd_opt_pi_prefix_len != 64) {
nd6log((LOG_INFO,
"nd6_ra_input: invalid prefixlen "
"%d for rfc2374 prefix %s, ignored\n",
pi->nd_opt_pi_prefix_len,
ip6_sprintf(&pi->nd_opt_pi_prefix)));
continue;
}
bzero(&pr, sizeof(pr));
pr.ndpr_prefix.sin6_family = AF_INET6;
pr.ndpr_prefix.sin6_len = sizeof(pr.ndpr_prefix);
pr.ndpr_prefix.sin6_addr = pi->nd_opt_pi_prefix;
pr.ndpr_ifp = (struct ifnet *)m->m_pkthdr.rcvif;
pr.ndpr_raf_onlink = (pi->nd_opt_pi_flags_reserved &
ND_OPT_PI_FLAG_ONLINK) ? 1 : 0;
pr.ndpr_raf_auto = (pi->nd_opt_pi_flags_reserved &
ND_OPT_PI_FLAG_AUTO) ? 1 : 0;
pr.ndpr_plen = pi->nd_opt_pi_prefix_len;
pr.ndpr_vltime = ntohl(pi->nd_opt_pi_valid_time);
pr.ndpr_pltime = ntohl(pi->nd_opt_pi_preferred_time);
pr.ndpr_lastupdate = time.tv_sec;
if (in6_init_prefix_ltimes(&pr))
continue; /* prefix lifetime init failed */
(void)prelist_update(&pr, dr, m);
}
}
/*
* MTU
*/
if (ndopts.nd_opts_mtu && ndopts.nd_opts_mtu->nd_opt_mtu_len == 1) {
u_long mtu;
u_long maxmtu;
mtu = ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
/* lower bound */
if (mtu < IPV6_MMTU) {
nd6log((LOG_INFO, "nd6_ra_input: bogus mtu option "
"mtu=%lu sent from %s, ignoring\n",
mtu, ip6_sprintf(&ip6->ip6_src)));
goto skip;
}
/* upper bound */
maxmtu = (ndi->maxmtu && ndi->maxmtu < ifp->if_mtu)
? ndi->maxmtu : ifp->if_mtu;
if (mtu <= maxmtu) {
int change = (ndi->linkmtu != mtu);
ndi->linkmtu = mtu;
if (change) /* in6_maxmtu may change */
in6_setmaxmtu();
} else {
nd6log((LOG_INFO, "nd6_ra_input: bogus mtu "
"mtu=%lu sent from %s; "
"exceeds maxmtu %lu, ignoring\n",
mtu, ip6_sprintf(&ip6->ip6_src), maxmtu));
}
}
skip:
/*
* Source link layer address
*/
{
char *lladdr = NULL;
int lladdrlen = 0;
if (ndopts.nd_opts_src_lladdr) {
lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
}
if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
nd6log((LOG_INFO,
"nd6_ra_input: lladdrlen mismatch for %s "
"(if %d, RA packet %d)\n", ip6_sprintf(&saddr6),
ifp->if_addrlen, lladdrlen - 2));
goto bad;
}
nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_ADVERT, 0);
/*
* Installing a link-layer address might change the state of the
* router's neighbor cache, which might also affect our on-link
* detection of adveritsed prefixes.
*/
pfxlist_onlink_check();
}
freeit:
m_freem(m);
return;
bad:
icmp6stat.icp6s_badra++;
m_freem(m);
}
/*
* default router list processing sub routines
*/
/* tell the change to user processes watching the routing socket. */
static void
nd6_rtmsg(cmd, rt)
int cmd;
struct rtentry *rt;
{
struct rt_addrinfo info;
bzero((caddr_t)&info, sizeof(info));
info.rti_info[RTAX_DST] = rt_key(rt);
info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
info.rti_info[RTAX_NETMASK] = rt_mask(rt);
if (rt->rt_ifp) {
info.rti_info[RTAX_IFP] =
TAILQ_FIRST(&rt->rt_ifp->if_addrlist)->ifa_addr;
info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr;
}
rt_missmsg(cmd, &info, rt->rt_flags, 0);
}
void
defrouter_addreq(new)
struct nd_defrouter *new;
{
struct sockaddr_in6 def, mask, gate;
struct rtentry *newrt = NULL;
int s;
int error;
Bzero(&def, sizeof(def));
Bzero(&mask, sizeof(mask));
Bzero(&gate, sizeof(gate)); /* for safety */
def.sin6_len = mask.sin6_len = gate.sin6_len =
sizeof(struct sockaddr_in6);
def.sin6_family = mask.sin6_family = gate.sin6_family = AF_INET6;
gate.sin6_addr = new->rtaddr;
#ifndef SCOPEDROUTING
gate.sin6_scope_id = 0; /* XXX */
#endif
s = splsoftnet();
error = rtrequest(RTM_ADD, (struct sockaddr *)&def,
(struct sockaddr *)&gate, (struct sockaddr *)&mask,
RTF_GATEWAY, &newrt);
if (newrt) {
nd6_rtmsg(RTM_ADD, newrt); /* tell user process */
newrt->rt_refcnt--;
}
if (error == 0)
new->installed = 1;
splx(s);
return;
}
/* Add a route to a given interface as default */
static void
defrouter_addifreq(ifp)
struct ifnet *ifp;
{
struct sockaddr_in6 def, mask;
struct ifaddr *ifa;
struct rtentry *newrt = NULL;
int error, flags;
struct rt_addrinfo info;
/* remove one if we have already installed one */
if (nd6_defif_installed)
defrouter_delifreq();
bzero(&def, sizeof(def));
bzero(&mask, sizeof(mask));
def.sin6_len = mask.sin6_len = sizeof(struct sockaddr_in6);
def.sin6_family = mask.sin6_family = AF_INET6;
/*
* Search for an ifaddr beloging to the specified interface.
* XXX: An IPv6 address are required to be assigned on the interface.
*/
if ((ifa = ifaof_ifpforaddr((struct sockaddr *)&def, ifp)) == NULL) {
nd6log((LOG_ERR, /* better error? */
"defrouter_addifreq: failed to find an ifaddr "
"to install a route to interface %s\n",
if_name(ifp)));
return;
}
/* RTF_CLONING is necessary to make sure to perform ND */
flags = ifa->ifa_flags | RTF_CLONING;
bzero(&info, sizeof(info));
info.rti_info[RTAX_DST] = (struct sockaddr *)&def;
info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)ifa->ifa_addr;
info.rti_info[RTAX_NETMASK] = (struct sockaddr *)&mask;
info.rti_info[RTAX_IFA] = (struct sockaddr *)ifa->ifa_addr;
info.rti_flags = flags;
error = rtrequest1(RTM_ADD, &info, &newrt);
if (error != 0) {
nd6log((LOG_ERR,
"defrouter_addifreq: failed to install a route to "
"interface %s (errno = %d)\n",
if_name(ifp), error));
if (newrt) /* maybe unnecessary, but do it for safety */
newrt->rt_refcnt--;
} else {
if (newrt) {
nd6_rtmsg(RTM_ADD, newrt);
newrt->rt_refcnt--;
}
}
nd6_defif_installed = ifa;
IFAREF(ifa);
}
/* Remove a default route points to interface */
static void
defrouter_delifreq()
{
struct sockaddr_in6 def, mask;
struct rtentry *oldrt = NULL;
if (!nd6_defif_installed)
return;
Bzero(&def, sizeof(def));
Bzero(&mask, sizeof(mask));
def.sin6_len = mask.sin6_len = sizeof(struct sockaddr_in6);
def.sin6_family = mask.sin6_family = AF_INET6;
rtrequest(RTM_DELETE, (struct sockaddr *)&def,
(struct sockaddr *)nd6_defif_installed->ifa_addr,
(struct sockaddr *)&mask, RTF_GATEWAY, &oldrt);
if (oldrt) {
nd6_rtmsg(RTM_DELETE, oldrt);
if (oldrt->rt_refcnt <= 0) {
/*
* XXX: borrowed from the RTM_DELETE case of
* rtrequest().
*/
oldrt->rt_refcnt++;
rtfree(oldrt);
}
}
IFAFREE(nd6_defif_installed);
nd6_defif_installed = NULL;
}
struct nd_defrouter *
defrouter_lookup(addr, ifp)
struct in6_addr *addr;
struct ifnet *ifp;
{
struct nd_defrouter *dr;
for (dr = TAILQ_FIRST(&nd_defrouter); dr;
dr = TAILQ_NEXT(dr, dr_entry)) {
if (dr->ifp == ifp && IN6_ARE_ADDR_EQUAL(addr, &dr->rtaddr)) {
return (dr);
}
}
return (NULL); /* search failed */
}
void
defrtrlist_del(dr)
struct nd_defrouter *dr;
{
struct nd_defrouter *deldr = NULL;
struct nd_prefix *pr;
/*
* Flush all the routing table entries that use the router
* as a next hop.
*/
if (!ip6_forwarding && ip6_accept_rtadv) /* XXX: better condition? */
rt6_flush(&dr->rtaddr, dr->ifp);
if (dr->installed) {
deldr = dr;
defrouter_delreq(dr);
}
TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
/*
* Also delete all the pointers to the router in each prefix lists.
*/
for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
struct nd_pfxrouter *pfxrtr;
if ((pfxrtr = pfxrtr_lookup(pr, dr)) != NULL)
pfxrtr_del(pfxrtr);
}
pfxlist_onlink_check();
/*
* If the router is the primary one, choose a new one.
* Note that defrouter_select() will remove the current gateway
* from the routing table.
*/
if (deldr)
defrouter_select();
free(dr, M_IP6NDP);
}
/*
* Remove the default route for a given router.
* This is just a subroutine function for defrouter_select(), and should
* not be called from anywhere else.
*/
static void
defrouter_delreq(dr)
struct nd_defrouter *dr;
{
struct sockaddr_in6 def, mask, gw;
struct rtentry *oldrt = NULL;
#ifdef DIAGNOSTIC
if (!dr)
panic("dr == NULL in defrouter_delreq");
#endif
Bzero(&def, sizeof(def));
Bzero(&mask, sizeof(mask));
Bzero(&gw, sizeof(gw)); /* for safety */
def.sin6_len = mask.sin6_len = gw.sin6_len =
sizeof(struct sockaddr_in6);
def.sin6_family = mask.sin6_family = gw.sin6_family = AF_INET6;
gw.sin6_addr = dr->rtaddr;
#ifndef SCOPEDROUTING
gw.sin6_scope_id = 0; /* XXX */
#endif
rtrequest(RTM_DELETE, (struct sockaddr *)&def,
(struct sockaddr *)&gw,
(struct sockaddr *)&mask, RTF_GATEWAY, &oldrt);
if (oldrt) {
nd6_rtmsg(RTM_DELETE, oldrt);
if (oldrt->rt_refcnt <= 0) {
/*
* XXX: borrowed from the RTM_DELETE case of
* rtrequest().
*/
oldrt->rt_refcnt++;
rtfree(oldrt);
}
}
dr->installed = 0;
}
/*
* remove all default routes from default router list
*/
void
defrouter_reset()
{
struct nd_defrouter *dr;
for (dr = TAILQ_FIRST(&nd_defrouter); dr;
dr = TAILQ_NEXT(dr, dr_entry))
defrouter_delreq(dr);
defrouter_delifreq();
/*
* XXX should we also nuke any default routers in the kernel, by
* going through them by rtalloc1()?
*/
}
/*
* Default Router Selection according to Section 6.3.6 of RFC 2461 and
* draft-ietf-ipngwg-router-selection:
* 1) Routers that are reachable or probably reachable should be preferred.
* If we have more than one (probably) reachable router, prefer ones
* with the highest router preference.
* 2) When no routers on the list are known to be reachable or
* probably reachable, routers SHOULD be selected in a round-robin
* fashion, regardless of router preference values.
* 3) If the Default Router List is empty, assume that all
* destinations are on-link.
*
* We assume nd_defrouter is sorted by router preference value.
* Since the code below covers both with and without router preference cases,
* we do not need to classify the cases by ifdef.
*
* At this moment, we do not try to install more than one default router,
* even when the multipath routing is available, because we're not sure about
* the benefits for stub hosts comparing to the risk of making the code
* complicated and the possibility of introducing bugs.
*/
void
defrouter_select()
{
int s = splsoftnet();
struct nd_defrouter *dr, *selected_dr = NULL, *installed_dr = NULL;
struct rtentry *rt = NULL;
struct llinfo_nd6 *ln = NULL;
/*
* This function should be called only when acting as an autoconfigured
* host. Although the remaining part of this function is not effective
* if the node is not an autoconfigured host, we explicitly exclude
* such cases here for safety.
*/
if (ip6_forwarding || !ip6_accept_rtadv) {
nd6log((LOG_WARNING,
"defrouter_select: called unexpectedly (forwarding=%d, "
"accept_rtadv=%d)\n", ip6_forwarding, ip6_accept_rtadv));
splx(s);
return;
}
/*
* Let's handle easy case (3) first:
* If default router list is empty, we should probably install
* an interface route and assume that all destinations are on-link.
*/
if (!TAILQ_FIRST(&nd_defrouter)) {
/*
* XXX: The specification does not say this mechanism should
* be restricted to hosts, but this would be not useful
* (even harmful) for routers.
* This test is meaningless due to a test at the beginning of
* the function, but we intentionally keep it to make the note
* clear.
*/
if (!ip6_forwarding) {
if (nd6_defifp) {
/*
* Install a route to the default interface
* as default route.
*/
defrouter_addifreq(nd6_defifp);
} else {
/*
* purge the existing route.
* XXX: is this really correct?
*/
defrouter_delifreq();
nd6log((LOG_INFO, "defrouter_select: "
"there's no default router and no default"
" interface\n"));
}
}
splx(s);
return;
}
/*
* If we have a default route for the default interface, delete it.
* Note that the existence of the route is checked in the delete
* function.
*/
defrouter_delifreq();
/*
* Search for a (probably) reachable router from the list.
* We just pick up the first reachable one (if any), assuming that
* the ordering rule of the list described in defrtrlist_update().
*/
for (dr = TAILQ_FIRST(&nd_defrouter); dr;
dr = TAILQ_NEXT(dr, dr_entry)) {
if (!selected_dr &&
(rt = nd6_lookup(&dr->rtaddr, 0, dr->ifp)) &&
(ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
ND6_IS_LLINFO_PROBREACH(ln)) {
selected_dr = dr;
}
if (dr->installed && !installed_dr)
installed_dr = dr;
else if (dr->installed && installed_dr) {
/* this should not happen. warn for diagnosis. */
log(LOG_ERR, "defrouter_select: more than one router"
" is installed\n");
}
}
/*
* If none of the default routers was found to be reachable,
* round-robin the list regardless of preference.
* Otherwise, if we have an installed router, check if the selected
* (reachable) router should really be preferred to the installed one.
* We only prefer the new router when the old one is not reachable
* or when the new one has a really higher preference value.
*/
if (!selected_dr) {
if (!installed_dr || !TAILQ_NEXT(installed_dr, dr_entry))
selected_dr = TAILQ_FIRST(&nd_defrouter);
else
selected_dr = TAILQ_NEXT(installed_dr, dr_entry);
} else if (installed_dr &&
(rt = nd6_lookup(&installed_dr->rtaddr, 0, installed_dr->ifp)) &&
(ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
ND6_IS_LLINFO_PROBREACH(ln) &&
rtpref(selected_dr) <= rtpref(installed_dr)) {
selected_dr = installed_dr;
}
/*
* If the selected router is different than the installed one,
* remove the installed router and install the selected one.
* Note that the selected router is never NULL here.
*/
if (installed_dr != selected_dr) {
if (installed_dr)
defrouter_delreq(installed_dr);
defrouter_addreq(selected_dr);
}
splx(s);
return;
}
/*
* for default router selection
* regards router-preference field as a 2-bit signed integer
*/
static int
rtpref(struct nd_defrouter *dr)
{
#ifdef RTPREF
switch (dr->flags & ND_RA_FLAG_RTPREF_MASK) {
case ND_RA_FLAG_RTPREF_HIGH:
return RTPREF_HIGH;
case ND_RA_FLAG_RTPREF_MEDIUM:
case ND_RA_FLAG_RTPREF_RSV:
return RTPREF_MEDIUM;
case ND_RA_FLAG_RTPREF_LOW:
return RTPREF_LOW;
default:
/*
* This case should never happen. If it did, it would mean a
* serious bug of kernel internal. We thus always bark here.
* Or, can we even panic?
*/
log(LOG_ERR, "rtpref: impossible RA flag %x", dr->flags);
return RTPREF_INVALID;
}
/* NOTREACHED */
#else
return 0;
#endif
}
static struct nd_defrouter *
defrtrlist_update(new)
struct nd_defrouter *new;
{
struct nd_defrouter *dr, *n;
int s = splsoftnet();
if ((dr = defrouter_lookup(&new->rtaddr, new->ifp)) != NULL) {
/* entry exists */
if (new->rtlifetime == 0) {
defrtrlist_del(dr);
dr = NULL;
} else {
int oldpref = rtpref(dr);
/* override */
dr->flags = new->flags; /* xxx flag check */
dr->rtlifetime = new->rtlifetime;
dr->expire = new->expire;
/*
* If the preference does not change, there's no need
* to sort the entries.
*/
if (rtpref(new) == oldpref) {
splx(s);
return (dr);
}
/*
* preferred router may be changed, so relocate
* this router.
* XXX: calling TAILQ_REMOVE directly is a bad manner.
* However, since defrtrlist_del() has many side
* effects, we intentionally do so here.
* defrouter_select() below will handle routing
* changes later.
*/
TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
n = dr;
goto insert;
}
splx(s);
return (dr);
}
/* entry does not exist */
if (new->rtlifetime == 0) {
splx(s);
return (NULL);
}
n = (struct nd_defrouter *)malloc(sizeof(*n), M_IP6NDP, M_NOWAIT);
if (n == NULL) {
splx(s);
return (NULL);
}
bzero(n, sizeof(*n));
*n = *new;
insert:
/*
* Insert the new router in the Default Router List;
* The Default Router List should be in the descending order
* of router-preferece. Routers with the same preference are
* sorted in the arriving time order.
*/
/* insert at the end of the group */
for (dr = TAILQ_FIRST(&nd_defrouter); dr;
dr = TAILQ_NEXT(dr, dr_entry)) {
if (rtpref(n) > rtpref(dr))
break;
}
if (dr)
TAILQ_INSERT_BEFORE(dr, n, dr_entry);
else
TAILQ_INSERT_TAIL(&nd_defrouter, n, dr_entry);
defrouter_select();
splx(s);
return (n);
}
static struct nd_pfxrouter *
pfxrtr_lookup(pr, dr)
struct nd_prefix *pr;
struct nd_defrouter *dr;
{
struct nd_pfxrouter *search;
for (search = pr->ndpr_advrtrs.lh_first; search; search = search->pfr_next) {
if (search->router == dr)
break;
}
return (search);
}
static void
pfxrtr_add(pr, dr)
struct nd_prefix *pr;
struct nd_defrouter *dr;
{
struct nd_pfxrouter *new;
new = (struct nd_pfxrouter *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT);
if (new == NULL)
return;
bzero(new, sizeof(*new));
new->router = dr;
LIST_INSERT_HEAD(&pr->ndpr_advrtrs, new, pfr_entry);
pfxlist_onlink_check();
}
static void
pfxrtr_del(pfr)
struct nd_pfxrouter *pfr;
{
LIST_REMOVE(pfr, pfr_entry);
free(pfr, M_IP6NDP);
}
struct nd_prefix *
nd6_prefix_lookup(pr)
struct nd_prefix *pr;
{
struct nd_prefix *search;
for (search = nd_prefix.lh_first; search; search = search->ndpr_next) {
if (pr->ndpr_ifp == search->ndpr_ifp &&
pr->ndpr_plen == search->ndpr_plen &&
in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
&search->ndpr_prefix.sin6_addr, pr->ndpr_plen)) {
break;
}
}
return (search);
}
int
nd6_prelist_add(pr, dr, newp)
struct nd_prefix *pr, **newp;
struct nd_defrouter *dr;
{
struct nd_prefix *new = NULL;
int i, s;
new = (struct nd_prefix *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT);
if (new == NULL)
return ENOMEM;
bzero(new, sizeof(*new));
*new = *pr;
if (newp != NULL)
*newp = new;
/* initilization */
LIST_INIT(&new->ndpr_advrtrs);
in6_prefixlen2mask(&new->ndpr_mask, new->ndpr_plen);
/* make prefix in the canonical form */
for (i = 0; i < 4; i++)
new->ndpr_prefix.sin6_addr.s6_addr32[i] &=
new->ndpr_mask.s6_addr32[i];
s = splsoftnet();
/* link ndpr_entry to nd_prefix list */
LIST_INSERT_HEAD(&nd_prefix, new, ndpr_entry);
splx(s);
/* ND_OPT_PI_FLAG_ONLINK processing */
if (new->ndpr_raf_onlink) {
int e;
if ((e = nd6_prefix_onlink(new)) != 0) {
nd6log((LOG_ERR, "nd6_prelist_add: failed to make "
"the prefix %s/%d on-link on %s (errno=%d)\n",
ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
/* proceed anyway. XXX: is it correct? */
}
}
if (dr)
pfxrtr_add(new, dr);
return 0;
}
void
prelist_remove(pr)
struct nd_prefix *pr;
{
struct nd_pfxrouter *pfr, *next;
int e, s;
/* make sure to invalidate the prefix until it is really freed. */
pr->ndpr_vltime = 0;
pr->ndpr_pltime = 0;
#if 0
/*
* Though these flags are now meaningless, we'd rather keep the value
* not to confuse users when executing "ndp -p".
*/
pr->ndpr_raf_onlink = 0;
pr->ndpr_raf_auto = 0;
#endif
if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0 &&
(e = nd6_prefix_offlink(pr)) != 0) {
nd6log((LOG_ERR, "prelist_remove: failed to make %s/%d offlink "
"on %s, errno=%d\n",
ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
/* what should we do? */
}
if (pr->ndpr_refcnt > 0)
return; /* notice here? */
s = splsoftnet();
/* unlink ndpr_entry from nd_prefix list */
LIST_REMOVE(pr, ndpr_entry);
/* free list of routers that adversed the prefix */
for (pfr = pr->ndpr_advrtrs.lh_first; pfr; pfr = next) {
next = pfr->pfr_next;
free(pfr, M_IP6NDP);
}
splx(s);
free(pr, M_IP6NDP);
pfxlist_onlink_check();
}
int
prelist_update(new, dr, m)
struct nd_prefix *new;
struct nd_defrouter *dr; /* may be NULL */
struct mbuf *m;
{
struct in6_ifaddr *ia6 = NULL, *ia6_match = NULL;
struct ifaddr *ifa;
struct ifnet *ifp = new->ndpr_ifp;
struct nd_prefix *pr;
int s = splsoftnet();
int error = 0;
int auth;
struct in6_addrlifetime lt6_tmp;
auth = 0;
if (m) {
/*
* Authenticity for NA consists authentication for
* both IP header and IP datagrams, doesn't it ?
*/
#if defined(M_AUTHIPHDR) && defined(M_AUTHIPDGM)
auth = (m->m_flags & M_AUTHIPHDR
&& m->m_flags & M_AUTHIPDGM) ? 1 : 0;
#endif
}
if ((pr = nd6_prefix_lookup(new)) != NULL) {
/*
* nd6_prefix_lookup() ensures that pr and new have the same
* prefix on a same interface.
*/
/*
* Update prefix information. Note that the on-link (L) bit
* and the autonomous (A) bit should NOT be changed from 1
* to 0.
*/
if (new->ndpr_raf_onlink == 1)
pr->ndpr_raf_onlink = 1;
if (new->ndpr_raf_auto == 1)
pr->ndpr_raf_auto = 1;
if (new->ndpr_raf_onlink) {
pr->ndpr_vltime = new->ndpr_vltime;
pr->ndpr_pltime = new->ndpr_pltime;
pr->ndpr_preferred = new->ndpr_preferred;
pr->ndpr_expire = new->ndpr_expire;
pr->ndpr_lastupdate = new->ndpr_lastupdate;
}
if (new->ndpr_raf_onlink &&
(pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
int e;
if ((e = nd6_prefix_onlink(pr)) != 0) {
nd6log((LOG_ERR,
"prelist_update: failed to make "
"the prefix %s/%d on-link on %s "
"(errno=%d)\n",
ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
/* proceed anyway. XXX: is it correct? */
}
}
if (dr && pfxrtr_lookup(pr, dr) == NULL)
pfxrtr_add(pr, dr);
} else {
struct nd_prefix *newpr = NULL;
if (new->ndpr_vltime == 0)
goto end;
if (new->ndpr_raf_onlink == 0 && new->ndpr_raf_auto == 0)
goto end;
error = nd6_prelist_add(new, dr, &newpr);
if (error != 0 || newpr == NULL) {
nd6log((LOG_NOTICE, "prelist_update: "
"nd6_prelist_add failed for %s/%d on %s "
"errno=%d, returnpr=%p\n",
ip6_sprintf(&new->ndpr_prefix.sin6_addr),
new->ndpr_plen, if_name(new->ndpr_ifp),
error, newpr));
goto end; /* we should just give up in this case. */
}
/*
* XXX: from the ND point of view, we can ignore a prefix
* with the on-link bit being zero. However, we need a
* prefix structure for references from autoconfigured
* addresses. Thus, we explicitly make sure that the prefix
* itself expires now.
*/
if (newpr->ndpr_raf_onlink == 0) {
newpr->ndpr_vltime = 0;
newpr->ndpr_pltime = 0;
in6_init_prefix_ltimes(newpr);
}
pr = newpr;
}
/*
* Address autoconfiguration based on Section 5.5.3 of RFC 2462.
* Note that pr must be non NULL at this point.
*/
/* 5.5.3 (a). Ignore the prefix without the A bit set. */
if (!new->ndpr_raf_auto)
goto end;
/*
* 5.5.3 (b). the link-local prefix should have been ignored in
* nd6_ra_input.
*/
/*
* 5.5.3 (c). Consistency check on lifetimes: pltime <= vltime.
* This should have been done in nd6_ra_input.
*/
/*
* 5.5.3 (d). If the prefix advertised does not match the prefix of an
* address already in the list, and the Valid Lifetime is not 0,
* form an address. Note that even a manually configured address
* should reject autoconfiguration of a new address.
*/
for (ifa = ifp->if_addrlist.tqh_first; ifa; ifa = ifa->ifa_list.tqe_next)
{
struct in6_ifaddr *ifa6;
int ifa_plen;
u_int32_t storedlifetime;
if (ifa->ifa_addr->sa_family != AF_INET6)
continue;
ifa6 = (struct in6_ifaddr *)ifa;
/*
* Spec is not clear here, but I believe we should concentrate
* on unicast (i.e. not anycast) addresses.
* XXX: other ia6_flags? detached or duplicated?
*/
if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0)
continue;
ifa_plen = in6_mask2len(&ifa6->ia_prefixmask.sin6_addr, NULL);
if (ifa_plen != new->ndpr_plen ||
!in6_are_prefix_equal(&ifa6->ia_addr.sin6_addr,
&new->ndpr_prefix.sin6_addr, ifa_plen))
continue;
if (ia6_match == NULL) /* remember the first one */
ia6_match = ifa6;
if ((ifa6->ia6_flags & IN6_IFF_AUTOCONF) == 0)
continue;
/*
* An already autoconfigured address matched. Now that we
* are sure there is at least one matched address, we can
* proceed to 5.5.3. (e): update the lifetimes according to the
* "two hours" rule and the privacy extension.
*/
#define TWOHOUR (120*60)
/*
* RFC2462 introduces the notion of StoredLifetime to the
* "two hours" rule as follows:
* the Lifetime associated with the previously autoconfigured
* address.
* Our interpretation of this definition is "the remaining
* lifetime to expiration at the evaluation time". One might
* be wondering if this interpretation is really conform to the
* RFC, because the text can read that "Lifetimes" are never
* decreased, and our definition of the "storedlifetime" below
* essentially reduces the "Valid Lifetime" advertised in the
* previous RA. But, this is due to the wording of the text,
* and our interpretation is the same as an author's intention.
* See the discussion in the IETF ipngwg ML in August 2001,
* with the Subject "StoredLifetime in RFC 2462".
*/
lt6_tmp = ifa6->ia6_lifetime;
if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME)
storedlifetime = ND6_INFINITE_LIFETIME;
else if (time.tv_sec - ifa6->ia6_updatetime >
lt6_tmp.ia6t_vltime) {
/*
* The case of "invalid" address. We should usually
* not see this case.
*/
storedlifetime = 0;
} else
storedlifetime = lt6_tmp.ia6t_vltime -
(time.tv_sec - ifa6->ia6_updatetime);
if (TWOHOUR < new->ndpr_vltime ||
storedlifetime < new->ndpr_vltime) {
lt6_tmp.ia6t_vltime = new->ndpr_vltime;
} else if (storedlifetime <= TWOHOUR
#if 0
/*
* This condition is logically redundant, so we just
* omit it.
* See IPng 6712, 6717, and 6721.
*/
&& new->ndpr_vltime <= storedlifetime
#endif
) {
if (auth) {
lt6_tmp.ia6t_vltime = new->ndpr_vltime;
}
} else {
/*
* new->ndpr_vltime <= TWOHOUR &&
* TWOHOUR < storedlifetime
*/
lt6_tmp.ia6t_vltime = TWOHOUR;
}
/* The 2 hour rule is not imposed for preferred lifetime. */
lt6_tmp.ia6t_pltime = new->ndpr_pltime;
in6_init_address_ltimes(pr, &lt6_tmp);
ifa6->ia6_lifetime = lt6_tmp;
ifa6->ia6_updatetime = time.tv_sec;
}
if (ia6_match == NULL && new->ndpr_vltime) {
/*
* No address matched and the valid lifetime is non-zero.
* Create a new address.
*/
if ((ia6 = in6_ifadd(new)) != NULL) {
/*
* note that we should use pr (not new) for reference.
*/
pr->ndpr_refcnt++;
ia6->ia6_ndpr = pr;
/*
* A newly added address might affect the status
* of other addresses, so we check and update it.
* XXX: what if address duplication happens?
*/
pfxlist_onlink_check();
} else {
/* just set an error. do not bark here. */
error = EADDRNOTAVAIL; /* XXX: might be unused. */
}
}
end:
splx(s);
return error;
}
/*
* A supplement function used in the on-link detection below;
* detect if a given prefix has a (probably) reachable advertising router.
* XXX: lengthy function name...
*/
static struct nd_pfxrouter *
find_pfxlist_reachable_router(pr)
struct nd_prefix *pr;
{
struct nd_pfxrouter *pfxrtr;
struct rtentry *rt;
struct llinfo_nd6 *ln;
for (pfxrtr = LIST_FIRST(&pr->ndpr_advrtrs); pfxrtr;
pfxrtr = LIST_NEXT(pfxrtr, pfr_entry)) {
if ((rt = nd6_lookup(&pfxrtr->router->rtaddr, 0,
pfxrtr->router->ifp)) &&
(ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
ND6_IS_LLINFO_PROBREACH(ln))
break; /* found */
}
return (pfxrtr);
}
/*
* Check if each prefix in the prefix list has at least one available router
* that advertised the prefix (a router is "available" if its neighbor cache
* entry is reachable or probably reachable).
* If the check fails, the prefix may be off-link, because, for example,
* we have moved from the network but the lifetime of the prefix has not
* expired yet. So we should not use the prefix if there is another prefix
* that has an available router.
* But, if there is no prefix that has an available router, we still regards
* all the prefixes as on-link. This is because we can't tell if all the
* routers are simply dead or if we really moved from the network and there
* is no router around us.
*/
void
pfxlist_onlink_check()
{
struct nd_prefix *pr;
struct in6_ifaddr *ifa;
/*
* Check if there is a prefix that has a reachable advertising
* router.
*/
for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
if (pr->ndpr_raf_onlink && find_pfxlist_reachable_router(pr))
break;
}
if (pr != NULL || TAILQ_FIRST(&nd_defrouter) != NULL) {
/*
* There is at least one prefix that has a reachable router,
* or at least a router which probably does not advertise
* any prefixes. The latter would be the case when we move
* to a new link where we have a router that does not provide
* prefixes and we configure an address by hand.
* Detach prefixes which have no reachable advertising
* router, and attach other prefixes.
*/
for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
/* XXX: a link-local prefix should never be detached */
if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
continue;
/*
* we aren't interested in prefixes without the L bit
* set.
*/
if (pr->ndpr_raf_onlink == 0)
continue;
if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
find_pfxlist_reachable_router(pr) == NULL)
pr->ndpr_stateflags |= NDPRF_DETACHED;
if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
find_pfxlist_reachable_router(pr) != 0)
pr->ndpr_stateflags &= ~NDPRF_DETACHED;
}
} else {
/* there is no prefix that has a reachable router */
for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
continue;
if (pr->ndpr_raf_onlink == 0)
continue;
if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0)
pr->ndpr_stateflags &= ~NDPRF_DETACHED;
}
}
/*
* Remove each interface route associated with a (just) detached
* prefix, and reinstall the interface route for a (just) attached
* prefix. Note that all attempt of reinstallation does not
* necessarily success, when a same prefix is shared among multiple
* interfaces. Such cases will be handled in nd6_prefix_onlink,
* so we don't have to care about them.
*/
for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
int e;
if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
continue;
if (pr->ndpr_raf_onlink == 0)
continue;
if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
(pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
if ((e = nd6_prefix_offlink(pr)) != 0) {
nd6log((LOG_ERR,
"pfxlist_onlink_check: failed to "
"make %s/%d offlink, errno=%d\n",
ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
pr->ndpr_plen, e));
}
}
if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
(pr->ndpr_stateflags & NDPRF_ONLINK) == 0 &&
pr->ndpr_raf_onlink) {
if ((e = nd6_prefix_onlink(pr)) != 0) {
nd6log((LOG_ERR,
"pfxlist_onlink_check: failed to "
"make %s/%d offlink, errno=%d\n",
ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
pr->ndpr_plen, e));
}
}
}
/*
* Changes on the prefix status might affect address status as well.
* Make sure that all addresses derived from an attached prefix are
* attached, and that all addresses derived from a detached prefix are
* detached. Note, however, that a manually configured address should
* always be attached.
* The precise detection logic is same as the one for prefixes.
*/
for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
if (!(ifa->ia6_flags & IN6_IFF_AUTOCONF))
continue;
if (ifa->ia6_ndpr == NULL) {
/*
* This can happen when we first configure the address
* (i.e. the address exists, but the prefix does not).
* XXX: complicated relationships...
*/
continue;
}
if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
break;
}
if (ifa) {
for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
continue;
if (ifa->ia6_ndpr == NULL) /* XXX: see above. */
continue;
if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
ifa->ia6_flags &= ~IN6_IFF_DETACHED;
else
ifa->ia6_flags |= IN6_IFF_DETACHED;
}
}
else {
for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
continue;
ifa->ia6_flags &= ~IN6_IFF_DETACHED;
}
}
}
int
nd6_prefix_onlink(pr)
struct nd_prefix *pr;
{
struct ifaddr *ifa;
struct ifnet *ifp = pr->ndpr_ifp;
struct sockaddr_in6 mask6;
struct nd_prefix *opr;
u_long rtflags;
int error = 0;
struct rtentry *rt = NULL;
/* sanity check */
if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
nd6log((LOG_ERR,
"nd6_prefix_onlink: %s/%d is already on-link\n",
ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen);
return (EEXIST));
}
/*
* Add the interface route associated with the prefix. Before
* installing the route, check if there's the same prefix on another
* interface, and the prefix has already installed the interface route.
* Although such a configuration is expected to be rare, we explicitly
* allow it.
*/
for (opr = nd_prefix.lh_first; opr; opr = opr->ndpr_next) {
if (opr == pr)
continue;
if ((opr->ndpr_stateflags & NDPRF_ONLINK) == 0)
continue;
if (opr->ndpr_plen == pr->ndpr_plen &&
in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
&opr->ndpr_prefix.sin6_addr, pr->ndpr_plen))
return (0);
}
/*
* We prefer link-local addresses as the associated interface address.
*/
/* search for a link-local addr */
ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
IN6_IFF_NOTREADY | IN6_IFF_ANYCAST);
if (ifa == NULL) {
/* XXX: freebsd does not have ifa_ifwithaf */
for (ifa = ifp->if_addrlist.tqh_first;
ifa;
ifa = ifa->ifa_list.tqe_next)
{
if (ifa->ifa_addr->sa_family == AF_INET6)
break;
}
/* should we care about ia6_flags? */
}
if (ifa == NULL) {
/*
* This can still happen, when, for example, we receive an RA
* containing a prefix with the L bit set and the A bit clear,
* after removing all IPv6 addresses on the receiving
* interface. This should, of course, be rare though.
*/
nd6log((LOG_NOTICE,
"nd6_prefix_onlink: failed to find any ifaddr"
" to add route for a prefix(%s/%d) on %s\n",
ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
pr->ndpr_plen, if_name(ifp)));
return (0);
}
/*
* in6_ifinit() sets nd6_rtrequest to ifa_rtrequest for all ifaddrs.
* ifa->ifa_rtrequest = nd6_rtrequest;
*/
bzero(&mask6, sizeof(mask6));
mask6.sin6_len = sizeof(mask6);
mask6.sin6_addr = pr->ndpr_mask;
/* rtrequest() will probably set RTF_UP, but we're not sure. */
rtflags = ifa->ifa_flags | RTF_UP;
if (nd6_need_cache(ifp)) {
/* explicitly set in case ifa_flags does not set the flag. */
rtflags |= RTF_CLONING;
} else {
/*
* explicitly clear the cloning bit in case ifa_flags sets it.
*/
rtflags &= ~RTF_CLONING;
}
error = rtrequest(RTM_ADD, (struct sockaddr *)&pr->ndpr_prefix,
ifa->ifa_addr, (struct sockaddr *)&mask6, rtflags, &rt);
if (error == 0) {
if (rt != NULL) /* this should be non NULL, though */
nd6_rtmsg(RTM_ADD, rt);
pr->ndpr_stateflags |= NDPRF_ONLINK;
} else {
nd6log((LOG_ERR, "nd6_prefix_onlink: failed to add route for a"
" prefix (%s/%d) on %s, gw=%s, mask=%s, flags=%lx "
"errno = %d\n",
ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
pr->ndpr_plen, if_name(ifp),
ip6_sprintf(&((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr),
ip6_sprintf(&mask6.sin6_addr), rtflags, error));
}
if (rt != NULL)
rt->rt_refcnt--;
return (error);
}
int
nd6_prefix_offlink(pr)
struct nd_prefix *pr;
{
int error = 0;
struct ifnet *ifp = pr->ndpr_ifp;
struct nd_prefix *opr;
struct sockaddr_in6 sa6, mask6;
struct rtentry *rt = NULL;
/* sanity check */
if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
nd6log((LOG_ERR,
"nd6_prefix_offlink: %s/%d is already off-link\n",
ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen));
return (EEXIST);
}
bzero(&sa6, sizeof(sa6));
sa6.sin6_family = AF_INET6;
sa6.sin6_len = sizeof(sa6);
bcopy(&pr->ndpr_prefix.sin6_addr, &sa6.sin6_addr,
sizeof(struct in6_addr));
bzero(&mask6, sizeof(mask6));
mask6.sin6_family = AF_INET6;
mask6.sin6_len = sizeof(sa6);
bcopy(&pr->ndpr_mask, &mask6.sin6_addr, sizeof(struct in6_addr));
error = rtrequest(RTM_DELETE, (struct sockaddr *)&sa6, NULL,
(struct sockaddr *)&mask6, 0, &rt);
if (error == 0) {
pr->ndpr_stateflags &= ~NDPRF_ONLINK;
/* report the route deletion to the routing socket. */
if (rt != NULL)
nd6_rtmsg(RTM_DELETE, rt);
/*
* There might be the same prefix on another interface,
* the prefix which could not be on-link just because we have
* the interface route (see comments in nd6_prefix_onlink).
* If there's one, try to make the prefix on-link on the
* interface.
*/
for (opr = nd_prefix.lh_first; opr; opr = opr->ndpr_next) {
if (opr == pr)
continue;
if ((opr->ndpr_stateflags & NDPRF_ONLINK) != 0)
continue;
/*
* KAME specific: detached prefixes should not be
* on-link.
*/
if ((opr->ndpr_stateflags & NDPRF_DETACHED) != 0)
continue;
if (opr->ndpr_plen == pr->ndpr_plen &&
in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
&opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) {
int e;
if ((e = nd6_prefix_onlink(opr)) != 0) {
nd6log((LOG_ERR,
"nd6_prefix_offlink: failed to "
"recover a prefix %s/%d from %s "
"to %s (errno = %d)\n",
ip6_sprintf(&opr->ndpr_prefix.sin6_addr),
opr->ndpr_plen, if_name(ifp),
if_name(opr->ndpr_ifp), e));
}
}
}
} else {
/* XXX: can we still set the NDPRF_ONLINK flag? */
nd6log((LOG_ERR,
"nd6_prefix_offlink: failed to delete route: "
"%s/%d on %s (errno = %d)\n",
ip6_sprintf(&sa6.sin6_addr), pr->ndpr_plen, if_name(ifp),
error));
}
if (rt != NULL) {
if (rt->rt_refcnt <= 0) {
/* XXX: we should free the entry ourselves. */
rt->rt_refcnt++;
rtfree(rt);
}
}
return (error);
}
static struct in6_ifaddr *
in6_ifadd(pr)
struct nd_prefix *pr;
{
struct ifnet *ifp = pr->ndpr_ifp;
struct ifaddr *ifa;
struct in6_aliasreq ifra;
struct in6_ifaddr *ia, *ib;
int error, plen0;
struct in6_addr mask;
int prefixlen = pr->ndpr_plen;
in6_prefixlen2mask(&mask, prefixlen);
/*
* find a link-local address (will be interface ID).
* Is it really mandatory? Theoretically, a global or a site-local
* address can be configured without a link-local address, if we
* have a unique interface identifier...
*
* it is not mandatory to have a link-local address, we can generate
* interface identifier on the fly. we do this because:
* (1) it should be the easiest way to find interface identifier.
* (2) RFC2462 5.4 suggesting the use of the same interface identifier
* for multiple addresses on a single interface, and possible shortcut
* of DAD. we omitted DAD for this reason in the past.
* (3) a user can prevent autoconfiguration of global address
* by removing link-local address by hand (this is partly because we
* don't have other way to control the use of IPv6 on a interface.
* this has been our design choice - cf. NRL's "ifconfig auto").
* (4) it is easier to manage when an interface has addresses
* with the same interface identifier, than to have multiple addresses
* with different interface identifiers.
*/
ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0); /* 0 is OK? */
if (ifa)
ib = (struct in6_ifaddr *)ifa;
else
return NULL;
#if 0 /* don't care link local addr state, and always do DAD */
/* if link-local address is not eligible, do not autoconfigure. */
if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_NOTREADY) {
printf("in6_ifadd: link-local address not ready\n");
return NULL;
}
#endif
/* prefixlen + ifidlen must be equal to 128 */
plen0 = in6_mask2len(&ib->ia_prefixmask.sin6_addr, NULL);
if (prefixlen != plen0) {
nd6log((LOG_ERR, "in6_ifadd: wrong prefixlen for %s"
"(prefix=%d ifid=%d)\n",
if_name(ifp), prefixlen, 128 - plen0));
return NULL;
}
/* make ifaddr */
bzero(&ifra, sizeof(ifra));
/*
* in6_update_ifa() does not use ifra_name, but we accurately set it
* for safety.
*/
strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
ifra.ifra_addr.sin6_family = AF_INET6;
ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
/* prefix */
bcopy(&pr->ndpr_prefix.sin6_addr, &ifra.ifra_addr.sin6_addr,
sizeof(ifra.ifra_addr.sin6_addr));
ifra.ifra_addr.sin6_addr.s6_addr32[0] &= mask.s6_addr32[0];
ifra.ifra_addr.sin6_addr.s6_addr32[1] &= mask.s6_addr32[1];
ifra.ifra_addr.sin6_addr.s6_addr32[2] &= mask.s6_addr32[2];
ifra.ifra_addr.sin6_addr.s6_addr32[3] &= mask.s6_addr32[3];
/* interface ID */
ifra.ifra_addr.sin6_addr.s6_addr32[0] |=
(ib->ia_addr.sin6_addr.s6_addr32[0] & ~mask.s6_addr32[0]);
ifra.ifra_addr.sin6_addr.s6_addr32[1] |=
(ib->ia_addr.sin6_addr.s6_addr32[1] & ~mask.s6_addr32[1]);
ifra.ifra_addr.sin6_addr.s6_addr32[2] |=
(ib->ia_addr.sin6_addr.s6_addr32[2] & ~mask.s6_addr32[2]);
ifra.ifra_addr.sin6_addr.s6_addr32[3] |=
(ib->ia_addr.sin6_addr.s6_addr32[3] & ~mask.s6_addr32[3]);
/* new prefix mask. */
ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
ifra.ifra_prefixmask.sin6_family = AF_INET6;
bcopy(&mask, &ifra.ifra_prefixmask.sin6_addr,
sizeof(ifra.ifra_prefixmask.sin6_addr));
/*
* lifetime.
* XXX: in6_init_address_ltimes would override these values later.
* We should reconsider this logic.
*/
ifra.ifra_lifetime.ia6t_vltime = pr->ndpr_vltime;
ifra.ifra_lifetime.ia6t_pltime = pr->ndpr_pltime;
/* XXX: scope zone ID? */
ifra.ifra_flags |= IN6_IFF_AUTOCONF; /* obey autoconf */
/* allocate ifaddr structure, link into chain, etc. */
if ((error = in6_update_ifa(ifp, &ifra, NULL)) != 0) {
nd6log((LOG_ERR,
"in6_ifadd: failed to make ifaddr %s on %s (errno=%d)\n",
ip6_sprintf(&ifra.ifra_addr.sin6_addr), if_name(ifp),
error));
return (NULL); /* ifaddr must not have been allocated. */
}
ia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
return (ia); /* this is always non-NULL */
}
int
in6_init_prefix_ltimes(struct nd_prefix *ndpr)
{
/* check if preferred lifetime > valid lifetime. RFC2462 5.5.3 (c) */
if (ndpr->ndpr_pltime > ndpr->ndpr_vltime) {
nd6log((LOG_INFO, "in6_init_prefix_ltimes: preferred lifetime"
"(%d) is greater than valid lifetime(%d)\n",
(u_int)ndpr->ndpr_pltime, (u_int)ndpr->ndpr_vltime));
return (EINVAL);
}
if (ndpr->ndpr_pltime == ND6_INFINITE_LIFETIME)
ndpr->ndpr_preferred = 0;
else
ndpr->ndpr_preferred = time.tv_sec + ndpr->ndpr_pltime;
if (ndpr->ndpr_vltime == ND6_INFINITE_LIFETIME)
ndpr->ndpr_expire = 0;
else
ndpr->ndpr_expire = time.tv_sec + ndpr->ndpr_vltime;
return 0;
}
static void
in6_init_address_ltimes(struct nd_prefix *new, struct in6_addrlifetime *lt6)
{
/* Valid lifetime must not be updated unless explicitly specified. */
/* init ia6t_expire */
if (lt6->ia6t_vltime == ND6_INFINITE_LIFETIME)
lt6->ia6t_expire = 0;
else {
lt6->ia6t_expire = time.tv_sec;
lt6->ia6t_expire += lt6->ia6t_vltime;
}
/* init ia6t_preferred */
if (lt6->ia6t_pltime == ND6_INFINITE_LIFETIME)
lt6->ia6t_preferred = 0;
else {
lt6->ia6t_preferred = time.tv_sec;
lt6->ia6t_preferred += lt6->ia6t_pltime;
}
}
/*
* Delete all the routing table entries that use the specified gateway.
* XXX: this function causes search through all entries of routing table, so
* it shouldn't be called when acting as a router.
*/
void
rt6_flush(gateway, ifp)
struct in6_addr *gateway;
struct ifnet *ifp;
{
struct radix_node_head *rnh = rt_tables[AF_INET6];
int s = splsoftnet();
/* We'll care only link-local addresses */
if (!IN6_IS_ADDR_LINKLOCAL(gateway)) {
splx(s);
return;
}
/* XXX: hack for KAME's link-local address kludge */
gateway->s6_addr16[1] = htons(ifp->if_index);
rnh->rnh_walktree(rnh, rt6_deleteroute, (void *)gateway);
splx(s);
}
static int
rt6_deleteroute(rn, arg)
struct radix_node *rn;
void *arg;
{
#define SIN6(s) ((struct sockaddr_in6 *)s)
struct rtentry *rt = (struct rtentry *)rn;
struct in6_addr *gate = (struct in6_addr *)arg;
if (rt->rt_gateway == NULL || rt->rt_gateway->sa_family != AF_INET6)
return (0);
if (!IN6_ARE_ADDR_EQUAL(gate, &SIN6(rt->rt_gateway)->sin6_addr))
return (0);
/*
* Do not delete a static route.
* XXX: this seems to be a bit ad-hoc. Should we consider the
* 'cloned' bit instead?
*/
if ((rt->rt_flags & RTF_STATIC) != 0)
return (0);
/*
* We delete only host route. This means, in particular, we don't
* delete default route.
*/
if ((rt->rt_flags & RTF_HOST) == 0)
return (0);
return (rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway,
rt_mask(rt), rt->rt_flags, 0));
#undef SIN6
}
int
nd6_setdefaultiface(ifindex)
int ifindex;
{
int error = 0;
if (ifindex < 0 || if_indexlim <= ifindex || !ifindex2ifnet[ifindex])
return (EINVAL);
if (nd6_defifindex != ifindex) {
nd6_defifindex = ifindex;
if (nd6_defifindex > 0) {
nd6_defifp = ifindex2ifnet[nd6_defifindex];
} else
nd6_defifp = NULL;
/*
* Rescan default router list, refresh default route(s).
*/
defrouter_select();
}
return (error);
}
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