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ad675b3279
freebsd-nq/sys/netinet6/nd6_rtr.c
Bjoern A. Zeeb ad675b3279 nd6 defrouter: consolidate nd_defrouter manipulations in nd6_rtr.c 
Move the nd_defrouter along with the sysctl handler from nd6.c to
nd6_rtr.c and make the variable file static.  Provide (temporary)
new accessor functions for code manipulating nd_defrouter from nd6.c,
and stop exporting functions no longer needed outside nd6_rtr.c.
This also shuffles a few functions around in nd6_rtr.c without
functional changes.

Given all nd_defrouter logic is now in one place we can tidy up the
code, locking and, and other open items.

MFC after:	3 weeks
X-MFC:		keep exporting the functions
Sponsored by:	Netflix
2019-11-13 12:05:48 +00:00

2668 lines
69 KiB
C
Raw Blame History

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $KAME: nd6_rtr.c,v 1.111 2001/04/27 01:37:15 jinmei Exp $
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/refcount.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/errno.h>
#include <sys/rmlock.h>
#include <sys/rwlock.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/queue.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_types.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <net/route_var.h>
#include <net/radix.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <net/if_llatbl.h>
#include <netinet6/in6_var.h>
#include <netinet6/in6_ifattach.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/nd6.h>
#include <netinet/icmp6.h>
#include <netinet6/scope6_var.h>
static int rtpref(struct nd_defrouter *);
static struct nd_defrouter *defrtrlist_update(struct nd_defrouter *);
static int prelist_update(struct nd_prefixctl *, struct nd_defrouter *,
struct mbuf *, int);
static struct in6_ifaddr *in6_ifadd(struct nd_prefixctl *, int);
static struct nd_pfxrouter *pfxrtr_lookup(struct nd_prefix *,
struct nd_defrouter *);
static void pfxrtr_add(struct nd_prefix *, struct nd_defrouter *);
static void pfxrtr_del(struct nd_pfxrouter *);
static struct nd_pfxrouter *find_pfxlist_reachable_router(struct nd_prefix *);
static void defrouter_delreq(struct nd_defrouter *);
static void nd6_rtmsg(int, struct rtentry *);
static int in6_init_prefix_ltimes(struct nd_prefix *);
static void in6_init_address_ltimes(struct nd_prefix *,
struct in6_addrlifetime *);
static int rt6_deleteroute(const struct rtentry *, void *);
VNET_DEFINE_STATIC(struct nd_drhead, nd_defrouter);
#define V_nd_defrouter VNET(nd_defrouter)
VNET_DECLARE(int, nd6_recalc_reachtm_interval);
#define V_nd6_recalc_reachtm_interval VNET(nd6_recalc_reachtm_interval)
VNET_DEFINE_STATIC(struct ifnet *, nd6_defifp);
VNET_DEFINE(int, nd6_defifindex);
#define V_nd6_defifp VNET(nd6_defifp)
VNET_DEFINE(int, ip6_use_tempaddr) = 0;
VNET_DEFINE(int, ip6_desync_factor);
VNET_DEFINE(u_int32_t, ip6_temp_preferred_lifetime) = DEF_TEMP_PREFERRED_LIFETIME;
VNET_DEFINE(u_int32_t, ip6_temp_valid_lifetime) = DEF_TEMP_VALID_LIFETIME;
VNET_DEFINE(int, ip6_temp_regen_advance) = TEMPADDR_REGEN_ADVANCE;
#ifdef EXPERIMENTAL
VNET_DEFINE(int, nd6_ignore_ipv6_only_ra) = 1;
#endif
/* RTPREF_MEDIUM has to be 0! */
#define RTPREF_HIGH 1
#define RTPREF_MEDIUM 0
#define RTPREF_LOW (-1)
#define RTPREF_RESERVED (-2)
#define RTPREF_INVALID (-3) /* internal */
static void
defrouter_ref(struct nd_defrouter *dr)
{
refcount_acquire(&dr->refcnt);
}
void
defrouter_rele(struct nd_defrouter *dr)
{
if (refcount_release(&dr->refcnt))
free(dr, M_IP6NDP);
}
/*
* Remove a router from the global list and optionally stash it in a
* caller-supplied queue.
*/
static void
defrouter_unlink(struct nd_defrouter *dr, struct nd_drhead *drq)
{
ND6_WLOCK_ASSERT();
TAILQ_REMOVE(&V_nd_defrouter, dr, dr_entry);
V_nd6_list_genid++;
if (drq != NULL)
TAILQ_INSERT_TAIL(drq, dr, dr_entry);
}
/*
* 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(struct mbuf *m, int off, int icmp6len)
{
struct ifnet *ifp;
struct ip6_hdr *ip6;
struct nd_router_solicit *nd_rs;
struct in6_addr saddr6;
union nd_opts ndopts;
char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
char *lladdr;
int lladdrlen;
ifp = m->m_pkthdr.rcvif;
/*
* Accept RS only when V_ip6_forwarding=1 and the interface has
* no ND6_IFF_ACCEPT_RTADV.
*/
if (!V_ip6_forwarding || ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV)
goto freeit;
/* RFC 6980: Nodes MUST silently ignore fragments */
if(m->m_flags & M_FRAGMENTED)
goto freeit;
/* Sanity checks */
ip6 = mtod(m, struct ip6_hdr *);
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(ip6bufs, &ip6->ip6_src),
ip6_sprintf(ip6bufd, &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.
*/
saddr6 = ip6->ip6_src;
if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
goto freeit;
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, icmp6len,);
nd_rs = (struct nd_router_solicit *)((caddr_t)ip6 + off);
#else
IP6_EXTHDR_GET(nd_rs, struct nd_router_solicit *, m, off, icmp6len);
if (nd_rs == NULL) {
ICMP6STAT_INC(icp6s_tooshort);
return;
}
#endif
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;
}
lladdr = NULL;
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_rs_input: lladdrlen mismatch for %s "
"(if %d, RS packet %d)\n",
ip6_sprintf(ip6bufs, &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_INC(icp6s_badrs);
m_freem(m);
}
#ifdef EXPERIMENTAL
/*
* An initial update routine for draft-ietf-6man-ipv6only-flag.
* We need to iterate over all default routers for the given
* interface to see whether they are all advertising the "S"
* (IPv6-Only) flag. If they do set, otherwise unset, the
* interface flag we later use to filter on.
*/
static void
defrtr_ipv6_only_ifp(struct ifnet *ifp)
{
struct nd_defrouter *dr;
bool ipv6_only, ipv6_only_old;
#ifdef INET
struct epoch_tracker et;
struct ifaddr *ifa;
bool has_ipv4_addr;
#endif
if (V_nd6_ignore_ipv6_only_ra != 0)
return;
ipv6_only = true;
ND6_RLOCK();
TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry)
if (dr->ifp == ifp &&
(dr->raflags & ND_RA_FLAG_IPV6_ONLY) == 0)
ipv6_only = false;
ND6_RUNLOCK();
IF_AFDATA_WLOCK(ifp);
ipv6_only_old = ND_IFINFO(ifp)->flags & ND6_IFF_IPV6_ONLY;
IF_AFDATA_WUNLOCK(ifp);
/* If nothing changed, we have an early exit. */
if (ipv6_only == ipv6_only_old)
return;
#ifdef INET
/*
* Should we want to set the IPV6-ONLY flag, check if the
* interface has a non-0/0 and non-link-local IPv4 address
* configured on it. If it has we will assume working
* IPv4 operations and will clear the interface flag.
*/
has_ipv4_addr = false;
if (ipv6_only) {
NET_EPOCH_ENTER(et);
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family != AF_INET)
continue;
if (in_canforward(
satosin(ifa->ifa_addr)->sin_addr)) {
has_ipv4_addr = true;
break;
}
}
NET_EPOCH_EXIT(et);
}
if (ipv6_only && has_ipv4_addr) {
log(LOG_NOTICE, "%s rcvd RA w/ IPv6-Only flag set but has IPv4 "
"configured, ignoring IPv6-Only flag.\n", ifp->if_xname);
ipv6_only = false;
}
#endif
IF_AFDATA_WLOCK(ifp);
if (ipv6_only)
ND_IFINFO(ifp)->flags |= ND6_IFF_IPV6_ONLY;
else
ND_IFINFO(ifp)->flags &= ~ND6_IFF_IPV6_ONLY;
IF_AFDATA_WUNLOCK(ifp);
#ifdef notyet
/* Send notification of flag change. */
#endif
}
static void
defrtr_ipv6_only_ipf_down(struct ifnet *ifp)
{
IF_AFDATA_WLOCK(ifp);
ND_IFINFO(ifp)->flags &= ~ND6_IFF_IPV6_ONLY;
IF_AFDATA_WUNLOCK(ifp);
}
#endif /* EXPERIMENTAL */
void
nd6_ifnet_link_event(void *arg __unused, struct ifnet *ifp, int linkstate)
{
/*
* XXX-BZ we might want to trigger re-evaluation of our default router
* availability. E.g., on link down the default router might be
* unreachable but a different interface might still have connectivity.
*/
#ifdef EXPERIMENTAL
if (linkstate == LINK_STATE_DOWN)
defrtr_ipv6_only_ipf_down(ifp);
#endif
}
/*
* 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(struct mbuf *m, int off, int icmp6len)
{
struct ifnet *ifp;
struct nd_ifinfo *ndi;
struct ip6_hdr *ip6;
struct nd_router_advert *nd_ra;
struct in6_addr saddr6;
struct nd_defrouter *dr;
union nd_opts ndopts;
char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
int mcast;
/*
* We only accept RAs only when the per-interface flag
* ND6_IFF_ACCEPT_RTADV is on the receiving interface.
*/
ifp = m->m_pkthdr.rcvif;
ndi = ND_IFINFO(ifp);
if (!(ndi->flags & ND6_IFF_ACCEPT_RTADV))
goto freeit;
/* RFC 6980: Nodes MUST silently ignore fragments */
if(m->m_flags & M_FRAGMENTED)
goto freeit;
ip6 = mtod(m, struct ip6_hdr *);
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(ip6bufs, &ip6->ip6_src),
ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
goto bad;
}
saddr6 = ip6->ip6_src;
if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) {
nd6log((LOG_ERR,
"nd6_ra_input: src %s is not link-local\n",
ip6_sprintf(ip6bufs, &saddr6)));
goto bad;
}
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, icmp6len,);
nd_ra = (struct nd_router_advert *)((caddr_t)ip6 + off);
#else
IP6_EXTHDR_GET(nd_ra, struct nd_router_advert *, m, off, icmp6len);
if (nd_ra == NULL) {
ICMP6STAT_INC(icp6s_tooshort);
return;
}
#endif
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;
}
mcast = 0;
dr = NULL;
{
struct nd_defrouter dr0;
u_int32_t advreachable = nd_ra->nd_ra_reachable;
/* remember if this is a multicasted advertisement */
if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
mcast = 1;
bzero(&dr0, sizeof(dr0));
dr0.rtaddr = saddr6;
dr0.raflags = nd_ra->nd_ra_flags_reserved;
/*
* Effectively-disable routes from RA messages when
* ND6_IFF_NO_RADR enabled on the receiving interface or
* (ip6.forwarding == 1 && ip6.rfc6204w3 != 1).
*/
if (ndi->flags & ND6_IFF_NO_RADR)
dr0.rtlifetime = 0;
else if (V_ip6_forwarding && !V_ip6_rfc6204w3)
dr0.rtlifetime = 0;
else
dr0.rtlifetime = ntohs(nd_ra->nd_ra_router_lifetime);
dr0.expire = time_uptime + dr0.rtlifetime;
dr0.ifp = ifp;
/* unspecified or not? (RFC 2461 6.3.4) */
if (advreachable) {
advreachable = ntohl(advreachable);
if (advreachable <= MAX_REACHABLE_TIME &&
ndi->basereachable != advreachable) {
ndi->basereachable = advreachable;
ndi->reachable = ND_COMPUTE_RTIME(ndi->basereachable);
ndi->recalctm = V_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) {
if (ndi->chlim < nd_ra->nd_ra_curhoplimit)
ndi->chlim = nd_ra->nd_ra_curhoplimit;
else if (ndi->chlim != nd_ra->nd_ra_curhoplimit) {
log(LOG_ERR, "RA with a lower CurHopLimit sent from "
"%s on %s (current = %d, received = %d). "
"Ignored.\n", ip6_sprintf(ip6bufs, &ip6->ip6_src),
if_name(ifp), ndi->chlim, nd_ra->nd_ra_curhoplimit);
}
}
dr = defrtrlist_update(&dr0);
#ifdef EXPERIMENTAL
defrtr_ipv6_only_ifp(ifp);
#endif
}
/*
* prefix
*/
if (ndopts.nd_opts_pi) {
struct nd_opt_hdr *pt;
struct nd_opt_prefix_info *pi = NULL;
struct nd_prefixctl 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(ip6bufs,
&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);
(void)prelist_update(&pr, dr, m, mcast);
}
}
if (dr != NULL) {
defrouter_rele(dr);
dr = NULL;
}
/*
* MTU
*/
if (ndopts.nd_opts_mtu && ndopts.nd_opts_mtu->nd_opt_mtu_len == 1) {
u_long mtu;
u_long maxmtu;
mtu = (u_long)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(ip6bufs, &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();
rt_updatemtu(ifp);
}
} else {
nd6log((LOG_INFO, "nd6_ra_input: bogus mtu "
"mtu=%lu sent from %s; "
"exceeds maxmtu %lu, ignoring\n",
mtu, ip6_sprintf(ip6bufs, &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(ip6bufs, &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_INC(icp6s_badra);
m_freem(m);
}
/* tell the change to user processes watching the routing socket. */
static void
nd6_rtmsg(int cmd, struct rtentry *rt)
{
struct rt_addrinfo info;
struct ifnet *ifp;
struct ifaddr *ifa;
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);
ifp = rt->rt_ifp;
if (ifp != NULL) {
struct epoch_tracker et;
NET_EPOCH_ENTER(et);
ifa = CK_STAILQ_FIRST(&ifp->if_addrhead);
info.rti_info[RTAX_IFP] = ifa->ifa_addr;
ifa_ref(ifa);
NET_EPOCH_EXIT(et);
info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr;
} else
ifa = NULL;
rt_missmsg_fib(cmd, &info, rt->rt_flags, 0, rt->rt_fibnum);
if (ifa != NULL)
ifa_free(ifa);
}
/*
* default router list processing sub routines
*/
static void
defrouter_addreq(struct nd_defrouter *new)
{
struct sockaddr_in6 def, mask, gate;
struct rtentry *newrt = NULL;
int error;
bzero(&def, sizeof(def));
bzero(&mask, sizeof(mask));
bzero(&gate, sizeof(gate));
def.sin6_len = mask.sin6_len = gate.sin6_len =
sizeof(struct sockaddr_in6);
def.sin6_family = gate.sin6_family = AF_INET6;
gate.sin6_addr = new->rtaddr;
error = in6_rtrequest(RTM_ADD, (struct sockaddr *)&def,
(struct sockaddr *)&gate, (struct sockaddr *)&mask,
RTF_GATEWAY, &newrt, new->ifp->if_fib);
if (newrt) {
nd6_rtmsg(RTM_ADD, newrt); /* tell user process */
RTFREE(newrt);
}
if (error == 0)
new->installed = 1;
}
struct nd_defrouter *
defrouter_lookup_locked(struct in6_addr *addr, struct ifnet *ifp)
{
struct nd_defrouter *dr;
ND6_LOCK_ASSERT();
TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry)
if (dr->ifp == ifp && IN6_ARE_ADDR_EQUAL(addr, &dr->rtaddr)) {
defrouter_ref(dr);
return (dr);
}
return (NULL);
}
struct nd_defrouter *
defrouter_lookup(struct in6_addr *addr, struct ifnet *ifp)
{
struct nd_defrouter *dr;
ND6_RLOCK();
dr = defrouter_lookup_locked(addr, ifp);
ND6_RUNLOCK();
return (dr);
}
/*
* Remove the default route for a given router.
* This is just a subroutine function for defrouter_select_fib(), and
* should not be called from anywhere else.
*/
static void
defrouter_delreq(struct nd_defrouter *dr)
{
struct sockaddr_in6 def, mask, gate;
struct rtentry *oldrt = NULL;
bzero(&def, sizeof(def));
bzero(&mask, sizeof(mask));
bzero(&gate, sizeof(gate));
def.sin6_len = mask.sin6_len = gate.sin6_len =
sizeof(struct sockaddr_in6);
def.sin6_family = gate.sin6_family = AF_INET6;
gate.sin6_addr = dr->rtaddr;
in6_rtrequest(RTM_DELETE, (struct sockaddr *)&def,
(struct sockaddr *)&gate,
(struct sockaddr *)&mask, RTF_GATEWAY, &oldrt, dr->ifp->if_fib);
if (oldrt) {
nd6_rtmsg(RTM_DELETE, oldrt);
RTFREE(oldrt);
}
dr->installed = 0;
}
/*
* Remove all default routes from default router list.
*/
void
defrouter_reset(void)
{
struct nd_defrouter *dr, **dra;
int count, i;
count = i = 0;
/*
* We can't delete routes with the ND lock held, so make a copy of the
* current default router list and use that when deleting routes.
*/
ND6_RLOCK();
TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry)
count++;
ND6_RUNLOCK();
dra = malloc(count * sizeof(*dra), M_TEMP, M_WAITOK | M_ZERO);
ND6_RLOCK();
TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
if (i == count)
break;
defrouter_ref(dr);
dra[i++] = dr;
}
ND6_RUNLOCK();
for (i = 0; i < count && dra[i] != NULL; i++) {
defrouter_delreq(dra[i]);
defrouter_rele(dra[i]);
}
free(dra, M_TEMP);
/*
* XXX should we also nuke any default routers in the kernel, by
* going through them by rtalloc1()?
*/
}
static void
defrouter_del(struct nd_defrouter *dr)
{
struct nd_defrouter *deldr = NULL;
struct nd_prefix *pr;
struct nd_pfxrouter *pfxrtr;
ND6_UNLOCK_ASSERT();
/*
* Flush all the routing table entries that use the router
* as a next hop.
*/
if (ND_IFINFO(dr->ifp)->flags & ND6_IFF_ACCEPT_RTADV)
rt6_flush(&dr->rtaddr, dr->ifp);
#ifdef EXPERIMENTAL
defrtr_ipv6_only_ifp(dr->ifp);
#endif
if (dr->installed) {
deldr = dr;
defrouter_delreq(dr);
}
/*
* Also delete all the pointers to the router in each prefix lists.
*/
ND6_WLOCK();
LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
if ((pfxrtr = pfxrtr_lookup(pr, dr)) != NULL)
pfxrtr_del(pfxrtr);
}
ND6_WUNLOCK();
pfxlist_onlink_check();
/*
* If the router is the primary one, choose a new one.
* Note that defrouter_select_fib() will remove the current
* gateway from the routing table.
*/
if (deldr)
defrouter_select_fib(deldr->ifp->if_fib);
/*
* Release the list reference.
*/
defrouter_rele(dr);
}
/*
* Look up a matching default router list entry and remove it. Returns true if a
* matching entry was found, false otherwise.
*/
bool
defrouter_remove(struct in6_addr *addr, struct ifnet *ifp)
{
struct nd_defrouter *dr;
ND6_WLOCK();
dr = defrouter_lookup_locked(addr, ifp);
if (dr == NULL) {
ND6_WUNLOCK();
return (false);
}
defrouter_unlink(dr, NULL);
ND6_WUNLOCK();
defrouter_del(dr);
defrouter_rele(dr);
return (true);
}
/*
* 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.
*
* We maintain a single list of routers for multiple FIBs, only considering one
* at a time based on the receiving interface's FIB. If @fibnum is RT_ALL_FIBS,
* we do the whole thing multiple times.
*/
void
defrouter_select_fib(int fibnum)
{
struct epoch_tracker et;
struct nd_defrouter *dr, *selected_dr, *installed_dr;
struct llentry *ln = NULL;
if (fibnum == RT_ALL_FIBS) {
for (fibnum = 0; fibnum < rt_numfibs; fibnum++) {
defrouter_select_fib(fibnum);
}
}
ND6_RLOCK();
/*
* Let's handle easy case (3) first:
* If default router list is empty, there's nothing to be done.
*/
if (TAILQ_EMPTY(&V_nd_defrouter)) {
ND6_RUNLOCK();
return;
}
/*
* 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().
*/
selected_dr = installed_dr = NULL;
TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
NET_EPOCH_ENTER(et);
if (selected_dr == NULL && dr->ifp->if_fib == fibnum &&
(ln = nd6_lookup(&dr->rtaddr, 0, dr->ifp)) &&
ND6_IS_LLINFO_PROBREACH(ln)) {
selected_dr = dr;
defrouter_ref(selected_dr);
}
NET_EPOCH_EXIT(et);
if (ln != NULL) {
LLE_RUNLOCK(ln);
ln = NULL;
}
if (dr->installed && dr->ifp->if_fib == fibnum) {
if (installed_dr == NULL) {
installed_dr = dr;
defrouter_ref(installed_dr);
} else {
/*
* this should not happen.
* warn for diagnosis.
*/
log(LOG_ERR, "defrouter_select_fib: 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 == NULL) {
if (installed_dr == NULL ||
TAILQ_NEXT(installed_dr, dr_entry) == NULL)
dr = TAILQ_FIRST(&V_nd_defrouter);
else
dr = TAILQ_NEXT(installed_dr, dr_entry);
/* Ensure we select a router for this FIB. */
TAILQ_FOREACH_FROM(dr, &V_nd_defrouter, dr_entry) {
if (dr->ifp->if_fib == fibnum) {
selected_dr = dr;
defrouter_ref(selected_dr);
break;
}
}
} else if (installed_dr != NULL) {
NET_EPOCH_ENTER(et);
if ((ln = nd6_lookup(&installed_dr->rtaddr, 0,
installed_dr->ifp)) &&
ND6_IS_LLINFO_PROBREACH(ln) &&
installed_dr->ifp->if_fib == fibnum &&
rtpref(selected_dr) <= rtpref(installed_dr)) {
defrouter_rele(selected_dr);
selected_dr = installed_dr;
}
NET_EPOCH_EXIT(et);
if (ln != NULL)
LLE_RUNLOCK(ln);
}
ND6_RUNLOCK();
/*
* If we selected a router for this FIB and it's different
* than the installed one, remove the installed router and
* install the selected one in its place.
*/
if (installed_dr != selected_dr) {
if (installed_dr != NULL) {
defrouter_delreq(installed_dr);
defrouter_rele(installed_dr);
}
if (selected_dr != NULL)
defrouter_addreq(selected_dr);
}
if (selected_dr != NULL)
defrouter_rele(selected_dr);
}
/*
* Maintain old KPI for default router selection.
* If unspecified, we can re-select routers for all FIBs.
*/
void
defrouter_select(void)
{
defrouter_select_fib(RT_ALL_FIBS);
}
/*
* for default router selection
* regards router-preference field as a 2-bit signed integer
*/
static int
rtpref(struct nd_defrouter *dr)
{
switch (dr->raflags & 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\n", dr->raflags);
return (RTPREF_INVALID);
}
/* NOTREACHED */
}
static struct nd_defrouter *
defrtrlist_update(struct nd_defrouter *new)
{
struct nd_defrouter *dr, *n;
uint64_t genid;
int oldpref;
bool writelocked;
if (new->rtlifetime == 0) {
defrouter_remove(&new->rtaddr, new->ifp);
return (NULL);
}
ND6_RLOCK();
writelocked = false;
restart:
dr = defrouter_lookup_locked(&new->rtaddr, new->ifp);
if (dr != NULL) {
oldpref = rtpref(dr);
/* override */
dr->raflags = new->raflags; /* 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. Also make sure the selected
* router is still installed in the kernel.
*/
if (dr->installed && rtpref(new) == oldpref) {
if (writelocked)
ND6_WUNLOCK();
else
ND6_RUNLOCK();
return (dr);
}
}
/*
* The router needs to be reinserted into the default router
* list, so upgrade to a write lock. If that fails and the list
* has potentially changed while the lock was dropped, we'll
* redo the lookup with the write lock held.
*/
if (!writelocked) {
writelocked = true;
if (!ND6_TRY_UPGRADE()) {
genid = V_nd6_list_genid;
ND6_RUNLOCK();
ND6_WLOCK();
if (genid != V_nd6_list_genid)
goto restart;
}
}
if (dr != NULL) {
/*
* The preferred router may have changed, so relocate this
* router.
*/
TAILQ_REMOVE(&V_nd_defrouter, dr, dr_entry);
n = dr;
} else {
n = malloc(sizeof(*n), M_IP6NDP, M_NOWAIT | M_ZERO);
if (n == NULL) {
ND6_WUNLOCK();
return (NULL);
}
memcpy(n, new, sizeof(*n));
/* Initialize with an extra reference for the caller. */
refcount_init(&n->refcnt, 2);
}
/*
* 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 */
TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
if (rtpref(n) > rtpref(dr))
break;
}
if (dr != NULL)
TAILQ_INSERT_BEFORE(dr, n, dr_entry);
else
TAILQ_INSERT_TAIL(&V_nd_defrouter, n, dr_entry);
V_nd6_list_genid++;
ND6_WUNLOCK();
defrouter_select_fib(new->ifp->if_fib);
return (n);
}
static struct nd_pfxrouter *
pfxrtr_lookup(struct nd_prefix *pr, struct nd_defrouter *dr)
{
struct nd_pfxrouter *search;
ND6_LOCK_ASSERT();
LIST_FOREACH(search, &pr->ndpr_advrtrs, pfr_entry) {
if (search->router == dr)
break;
}
return (search);
}
static void
pfxrtr_add(struct nd_prefix *pr, struct nd_defrouter *dr)
{
struct nd_pfxrouter *new;
bool update;
ND6_UNLOCK_ASSERT();
ND6_RLOCK();
if (pfxrtr_lookup(pr, dr) != NULL) {
ND6_RUNLOCK();
return;
}
ND6_RUNLOCK();
new = malloc(sizeof(*new), M_IP6NDP, M_NOWAIT | M_ZERO);
if (new == NULL)
return;
defrouter_ref(dr);
new->router = dr;
ND6_WLOCK();
if (pfxrtr_lookup(pr, dr) == NULL) {
LIST_INSERT_HEAD(&pr->ndpr_advrtrs, new, pfr_entry);
update = true;
} else {
/* We lost a race to add the reference. */
defrouter_rele(dr);
free(new, M_IP6NDP);
update = false;
}
ND6_WUNLOCK();
if (update)
pfxlist_onlink_check();
}
static void
pfxrtr_del(struct nd_pfxrouter *pfr)
{
ND6_WLOCK_ASSERT();
LIST_REMOVE(pfr, pfr_entry);
defrouter_rele(pfr->router);
free(pfr, M_IP6NDP);
}
static struct nd_prefix *
nd6_prefix_lookup_locked(struct nd_prefixctl *key)
{
struct nd_prefix *search;
ND6_LOCK_ASSERT();
LIST_FOREACH(search, &V_nd_prefix, ndpr_entry) {
if (key->ndpr_ifp == search->ndpr_ifp &&
key->ndpr_plen == search->ndpr_plen &&
in6_are_prefix_equal(&key->ndpr_prefix.sin6_addr,
&search->ndpr_prefix.sin6_addr, key->ndpr_plen)) {
nd6_prefix_ref(search);
break;
}
}
return (search);
}
struct nd_prefix *
nd6_prefix_lookup(struct nd_prefixctl *key)
{
struct nd_prefix *search;
ND6_RLOCK();
search = nd6_prefix_lookup_locked(key);
ND6_RUNLOCK();
return (search);
}
void
nd6_prefix_ref(struct nd_prefix *pr)
{
refcount_acquire(&pr->ndpr_refcnt);
}
void
nd6_prefix_rele(struct nd_prefix *pr)
{
if (refcount_release(&pr->ndpr_refcnt)) {
KASSERT(LIST_EMPTY(&pr->ndpr_advrtrs),
("prefix %p has advertising routers", pr));
free(pr, M_IP6NDP);
}
}
int
nd6_prelist_add(struct nd_prefixctl *pr, struct nd_defrouter *dr,
struct nd_prefix **newp)
{
struct nd_prefix *new;
char ip6buf[INET6_ADDRSTRLEN];
int error;
new = malloc(sizeof(*new), M_IP6NDP, M_NOWAIT | M_ZERO);
if (new == NULL)
return (ENOMEM);
refcount_init(&new->ndpr_refcnt, newp != NULL ? 2 : 1);
new->ndpr_ifp = pr->ndpr_ifp;
new->ndpr_prefix = pr->ndpr_prefix;
new->ndpr_plen = pr->ndpr_plen;
new->ndpr_vltime = pr->ndpr_vltime;
new->ndpr_pltime = pr->ndpr_pltime;
new->ndpr_flags = pr->ndpr_flags;
if ((error = in6_init_prefix_ltimes(new)) != 0) {
free(new, M_IP6NDP);
return (error);
}
new->ndpr_lastupdate = time_uptime;
/* initialization */
LIST_INIT(&new->ndpr_advrtrs);
in6_prefixlen2mask(&new->ndpr_mask, new->ndpr_plen);
/* make prefix in the canonical form */
IN6_MASK_ADDR(&new->ndpr_prefix.sin6_addr, &new->ndpr_mask);
ND6_WLOCK();
LIST_INSERT_HEAD(&V_nd_prefix, new, ndpr_entry);
V_nd6_list_genid++;
ND6_WUNLOCK();
/* ND_OPT_PI_FLAG_ONLINK processing */
if (new->ndpr_raf_onlink) {
struct epoch_tracker et;
ND6_ONLINK_LOCK();
NET_EPOCH_ENTER(et);
if ((error = 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(ip6buf, &pr->ndpr_prefix.sin6_addr),
pr->ndpr_plen, if_name(pr->ndpr_ifp), error));
/* proceed anyway. XXX: is it correct? */
}
NET_EPOCH_EXIT(et);
ND6_ONLINK_UNLOCK();
}
if (dr != NULL)
pfxrtr_add(new, dr);
if (newp != NULL)
*newp = new;
return (0);
}
/*
* Remove a prefix from the prefix list and optionally stash it in a
* caller-provided list.
*
* The ND6 lock must be held.
*/
void
nd6_prefix_unlink(struct nd_prefix *pr, struct nd_prhead *list)
{
ND6_WLOCK_ASSERT();
LIST_REMOVE(pr, ndpr_entry);
V_nd6_list_genid++;
if (list != NULL)
LIST_INSERT_HEAD(list, pr, ndpr_entry);
}
/*
* Free an unlinked prefix, first marking it off-link if necessary.
*/
void
nd6_prefix_del(struct nd_prefix *pr)
{
struct nd_pfxrouter *pfr, *next;
int e;
char ip6buf[INET6_ADDRSTRLEN];
KASSERT(pr->ndpr_addrcnt == 0,
("prefix %p has referencing addresses", pr));
ND6_UNLOCK_ASSERT();
/*
* Though these flags are now meaningless, we'd rather keep the value
* of pr->ndpr_raf_onlink and pr->ndpr_raf_auto not to confuse users
* when executing "ndp -p".
*/
if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
ND6_ONLINK_LOCK();
if ((e = nd6_prefix_offlink(pr)) != 0) {
nd6log((LOG_ERR,
"nd6_prefix_del: failed to make %s/%d offlink "
"on %s, errno=%d\n",
ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
/* what should we do? */
}
ND6_ONLINK_UNLOCK();
}
/* Release references to routers that have advertised this prefix. */
ND6_WLOCK();
LIST_FOREACH_SAFE(pfr, &pr->ndpr_advrtrs, pfr_entry, next)
pfxrtr_del(pfr);
ND6_WUNLOCK();
nd6_prefix_rele(pr);
pfxlist_onlink_check();
}
static int
prelist_update(struct nd_prefixctl *new, struct nd_defrouter *dr,
struct mbuf *m, int mcast)
{
struct in6_ifaddr *ia6 = NULL, *ia6_match = NULL;
struct ifaddr *ifa;
struct ifnet *ifp = new->ndpr_ifp;
struct nd_prefix *pr;
int error = 0;
int auth;
struct in6_addrlifetime lt6_tmp;
char ip6buf[INET6_ADDRSTRLEN];
NET_EPOCH_ASSERT();
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));
#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;
(void)in6_init_prefix_ltimes(pr); /* XXX error case? */
pr->ndpr_lastupdate = time_uptime;
}
if (new->ndpr_raf_onlink &&
(pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
ND6_ONLINK_LOCK();
if ((error = 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(ip6buf,
&pr->ndpr_prefix.sin6_addr),
pr->ndpr_plen, if_name(pr->ndpr_ifp),
error));
/* proceed anyway. XXX: is it correct? */
}
ND6_ONLINK_UNLOCK();
}
if (dr != NULL)
pfxrtr_add(pr, dr);
} else {
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, &pr);
if (error != 0) {
nd6log((LOG_NOTICE, "prelist_update: "
"nd6_prelist_add failed for %s/%d on %s errno=%d\n",
ip6_sprintf(ip6buf, &new->ndpr_prefix.sin6_addr),
new->ndpr_plen, if_name(new->ndpr_ifp), error));
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 (pr->ndpr_raf_onlink == 0) {
pr->ndpr_vltime = 0;
pr->ndpr_pltime = 0;
in6_init_prefix_ltimes(pr);
}
}
/*
* 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. */
if (new->ndpr_pltime > new->ndpr_vltime) {
error = EINVAL; /* XXX: won't be used */
goto end;
}
/*
* 5.5.3 (d). If the prefix advertised is not equal to the prefix of
* an address configured by stateless autoconfiguration already in the
* list of addresses associated with the interface, and the Valid
* Lifetime is not 0, form an address. We first check if we have
* a matching prefix.
* Note: we apply a clarification in rfc2462bis-02 here. We only
* consider autoconfigured addresses while RFC2462 simply said
* "address".
*/
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
struct in6_ifaddr *ifa6;
u_int32_t remaininglifetime;
if (ifa->ifa_addr->sa_family != AF_INET6)
continue;
ifa6 = (struct in6_ifaddr *)ifa;
/*
* We only consider autoconfigured addresses as per rfc2462bis.
*/
if (!(ifa6->ia6_flags & IN6_IFF_AUTOCONF))
continue;
/*
* 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;
/*
* Ignore the address if it is not associated with a prefix
* or is associated with a prefix that is different from this
* one. (pr is never NULL here)
*/
if (ifa6->ia6_ndpr != pr)
continue;
if (ia6_match == NULL) /* remember the first one */
ia6_match = ifa6;
/*
* 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.
* We apply some clarifications in rfc2462bis:
* - use remaininglifetime instead of storedlifetime as a
* variable name
* - remove the dead code in the "two-hour" rule
*/
#define TWOHOUR (120*60)
lt6_tmp = ifa6->ia6_lifetime;
if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME)
remaininglifetime = ND6_INFINITE_LIFETIME;
else if (time_uptime - ifa6->ia6_updatetime >
lt6_tmp.ia6t_vltime) {
/*
* The case of "invalid" address. We should usually
* not see this case.
*/
remaininglifetime = 0;
} else
remaininglifetime = lt6_tmp.ia6t_vltime -
(time_uptime - ifa6->ia6_updatetime);
/* when not updating, keep the current stored lifetime. */
lt6_tmp.ia6t_vltime = remaininglifetime;
if (TWOHOUR < new->ndpr_vltime ||
remaininglifetime < new->ndpr_vltime) {
lt6_tmp.ia6t_vltime = new->ndpr_vltime;
} else if (remaininglifetime <= TWOHOUR) {
if (auth) {
lt6_tmp.ia6t_vltime = new->ndpr_vltime;
}
} else {
/*
* new->ndpr_vltime <= TWOHOUR &&
* TWOHOUR < remaininglifetime
*/
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);
/*
* We need to treat lifetimes for temporary addresses
* differently, according to
* draft-ietf-ipv6-privacy-addrs-v2-01.txt 3.3 (1);
* we only update the lifetimes when they are in the maximum
* intervals.
*/
if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
u_int32_t maxvltime, maxpltime;
if (V_ip6_temp_valid_lifetime >
(u_int32_t)((time_uptime - ifa6->ia6_createtime) +
V_ip6_desync_factor)) {
maxvltime = V_ip6_temp_valid_lifetime -
(time_uptime - ifa6->ia6_createtime) -
V_ip6_desync_factor;
} else
maxvltime = 0;
if (V_ip6_temp_preferred_lifetime >
(u_int32_t)((time_uptime - ifa6->ia6_createtime) +
V_ip6_desync_factor)) {
maxpltime = V_ip6_temp_preferred_lifetime -
(time_uptime - ifa6->ia6_createtime) -
V_ip6_desync_factor;
} else
maxpltime = 0;
if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME ||
lt6_tmp.ia6t_vltime > maxvltime) {
lt6_tmp.ia6t_vltime = maxvltime;
}
if (lt6_tmp.ia6t_pltime == ND6_INFINITE_LIFETIME ||
lt6_tmp.ia6t_pltime > maxpltime) {
lt6_tmp.ia6t_pltime = maxpltime;
}
}
ifa6->ia6_lifetime = lt6_tmp;
ifa6->ia6_updatetime = time_uptime;
}
if (ia6_match == NULL && new->ndpr_vltime) {
int ifidlen;
/*
* 5.5.3 (d) (continued)
* No address matched and the valid lifetime is non-zero.
* Create a new address.
*/
/*
* Prefix Length check:
* If the sum of the prefix length and interface identifier
* length does not equal 128 bits, the Prefix Information
* option MUST be ignored. The length of the interface
* identifier is defined in a separate link-type specific
* document.
*/
ifidlen = in6_if2idlen(ifp);
if (ifidlen < 0) {
/* this should not happen, so we always log it. */
log(LOG_ERR, "prelist_update: IFID undefined (%s)\n",
if_name(ifp));
goto end;
}
if (ifidlen + pr->ndpr_plen != 128) {
nd6log((LOG_INFO,
"prelist_update: invalid prefixlen "
"%d for %s, ignored\n",
pr->ndpr_plen, if_name(ifp)));
goto end;
}
if ((ia6 = in6_ifadd(new, mcast)) != NULL) {
/*
* note that we should use pr (not new) for reference.
*/
pr->ndpr_addrcnt++;
ia6->ia6_ndpr = pr;
/*
* RFC 3041 3.3 (2).
* When a new public address is created as described
* in RFC2462, also create a new temporary address.
*
* RFC 3041 3.5.
* When an interface connects to a new link, a new
* randomized interface identifier should be generated
* immediately together with a new set of temporary
* addresses. Thus, we specifiy 1 as the 2nd arg of
* in6_tmpifadd().
*/
if (V_ip6_use_tempaddr) {
int e;
if ((e = in6_tmpifadd(ia6, 1, 1)) != 0) {
nd6log((LOG_NOTICE, "prelist_update: "
"failed to create a temporary "
"address, errno=%d\n",
e));
}
}
ifa_free(&ia6->ia_ifa);
/*
* 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:
if (pr != NULL)
nd6_prefix_rele(pr);
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(struct nd_prefix *pr)
{
struct epoch_tracker et;
struct nd_pfxrouter *pfxrtr;
struct llentry *ln;
int canreach;
ND6_LOCK_ASSERT();
NET_EPOCH_ENTER(et);
LIST_FOREACH(pfxrtr, &pr->ndpr_advrtrs, pfr_entry) {
ln = nd6_lookup(&pfxrtr->router->rtaddr, 0, pfxrtr->router->ifp);
if (ln == NULL)
continue;
canreach = ND6_IS_LLINFO_PROBREACH(ln);
LLE_RUNLOCK(ln);
if (canreach)
break;
}
NET_EPOCH_EXIT(et);
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 regard
* 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(void)
{
struct nd_prefix *pr;
struct in6_ifaddr *ifa;
struct nd_defrouter *dr;
struct nd_pfxrouter *pfxrtr = NULL;
struct rm_priotracker in6_ifa_tracker;
uint64_t genid;
uint32_t flags;
ND6_ONLINK_LOCK();
ND6_RLOCK();
/*
* Check if there is a prefix that has a reachable advertising
* router.
*/
LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
if (pr->ndpr_raf_onlink && find_pfxlist_reachable_router(pr))
break;
}
/*
* If we have no such prefix, check whether we still have a router
* that does not advertise any prefixes.
*/
if (pr == NULL) {
TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
struct nd_prefix *pr0;
LIST_FOREACH(pr0, &V_nd_prefix, ndpr_entry) {
if ((pfxrtr = pfxrtr_lookup(pr0, dr)) != NULL)
break;
}
if (pfxrtr != NULL)
break;
}
}
if (pr != NULL || (!TAILQ_EMPTY(&V_nd_defrouter) && pfxrtr == 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.
*/
LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
/* XXX: a link-local prefix should never be detached */
if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr) ||
pr->ndpr_raf_onlink == 0 ||
pr->ndpr_raf_auto == 0)
continue;
if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
find_pfxlist_reachable_router(pr) == NULL)
pr->ndpr_stateflags |= NDPRF_DETACHED;
else if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
find_pfxlist_reachable_router(pr) != NULL)
pr->ndpr_stateflags &= ~NDPRF_DETACHED;
}
} else {
/* there is no prefix that has a reachable router */
LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr) ||
pr->ndpr_raf_onlink == 0 ||
pr->ndpr_raf_auto == 0)
continue;
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.
*/
restart:
LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
char ip6buf[INET6_ADDRSTRLEN];
int e;
if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr) ||
pr->ndpr_raf_onlink == 0 ||
pr->ndpr_raf_auto == 0)
continue;
flags = pr->ndpr_stateflags & (NDPRF_DETACHED | NDPRF_ONLINK);
if (flags == 0 || flags == (NDPRF_DETACHED | NDPRF_ONLINK)) {
genid = V_nd6_list_genid;
ND6_RUNLOCK();
if ((flags & NDPRF_ONLINK) != 0 &&
(e = nd6_prefix_offlink(pr)) != 0) {
nd6log((LOG_ERR,
"pfxlist_onlink_check: failed to "
"make %s/%d offlink, errno=%d\n",
ip6_sprintf(ip6buf,
&pr->ndpr_prefix.sin6_addr),
pr->ndpr_plen, e));
} else if ((flags & NDPRF_ONLINK) == 0 &&
(e = nd6_prefix_onlink(pr)) != 0) {
nd6log((LOG_ERR,
"pfxlist_onlink_check: failed to "
"make %s/%d onlink, errno=%d\n",
ip6_sprintf(ip6buf,
&pr->ndpr_prefix.sin6_addr),
pr->ndpr_plen, e));
}
ND6_RLOCK();
if (genid != V_nd6_list_genid)
goto restart;
}
}
/*
* 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.
*/
IN6_IFADDR_RLOCK(&in6_ifa_tracker);
CK_STAILQ_FOREACH(ifa, &V_in6_ifaddrhead, ia_link) {
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) {
CK_STAILQ_FOREACH(ifa, &V_in6_ifaddrhead, ia_link) {
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)) {
if (ifa->ia6_flags & IN6_IFF_DETACHED) {
ifa->ia6_flags &= ~IN6_IFF_DETACHED;
ifa->ia6_flags |= IN6_IFF_TENTATIVE;
nd6_dad_start((struct ifaddr *)ifa, 0);
}
} else {
ifa->ia6_flags |= IN6_IFF_DETACHED;
}
}
} else {
CK_STAILQ_FOREACH(ifa, &V_in6_ifaddrhead, ia_link) {
if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
continue;
if (ifa->ia6_flags & IN6_IFF_DETACHED) {
ifa->ia6_flags &= ~IN6_IFF_DETACHED;
ifa->ia6_flags |= IN6_IFF_TENTATIVE;
/* Do we need a delay in this case? */
nd6_dad_start((struct ifaddr *)ifa, 0);
}
}
}
IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
ND6_RUNLOCK();
ND6_ONLINK_UNLOCK();
}
static int
nd6_prefix_onlink_rtrequest(struct nd_prefix *pr, struct ifaddr *ifa)
{
struct sockaddr_dl sdl;
struct rtentry *rt;
struct sockaddr_in6 mask6;
u_long rtflags;
int error, a_failure, fibnum, maxfib;
/*
* 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;
rtflags = (ifa->ifa_flags & ~IFA_RTSELF) | RTF_UP;
bzero(&sdl, sizeof(struct sockaddr_dl));
sdl.sdl_len = sizeof(struct sockaddr_dl);
sdl.sdl_family = AF_LINK;
sdl.sdl_type = ifa->ifa_ifp->if_type;
sdl.sdl_index = ifa->ifa_ifp->if_index;
if(V_rt_add_addr_allfibs) {
fibnum = 0;
maxfib = rt_numfibs;
} else {
fibnum = ifa->ifa_ifp->if_fib;
maxfib = fibnum + 1;
}
a_failure = 0;
for (; fibnum < maxfib; fibnum++) {
rt = NULL;
error = in6_rtrequest(RTM_ADD,
(struct sockaddr *)&pr->ndpr_prefix, (struct sockaddr *)&sdl,
(struct sockaddr *)&mask6, rtflags, &rt, fibnum);
if (error == 0) {
KASSERT(rt != NULL, ("%s: in6_rtrequest return no "
"error(%d) but rt is NULL, pr=%p, ifa=%p", __func__,
error, pr, ifa));
RT_LOCK(rt);
nd6_rtmsg(RTM_ADD, rt);
RT_UNLOCK(rt);
pr->ndpr_stateflags |= NDPRF_ONLINK;
} else {
char ip6buf[INET6_ADDRSTRLEN];
char ip6bufg[INET6_ADDRSTRLEN];
char ip6bufm[INET6_ADDRSTRLEN];
struct sockaddr_in6 *sin6;
sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
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(ip6buf, &pr->ndpr_prefix.sin6_addr),
pr->ndpr_plen, if_name(pr->ndpr_ifp),
ip6_sprintf(ip6bufg, &sin6->sin6_addr),
ip6_sprintf(ip6bufm, &mask6.sin6_addr),
rtflags, error));
/* Save last error to return, see rtinit(). */
a_failure = error;
}
if (rt != NULL) {
RT_LOCK(rt);
RT_REMREF(rt);
RT_UNLOCK(rt);
}
}
/* Return the last error we got. */
return (a_failure);
}
int
nd6_prefix_onlink(struct nd_prefix *pr)
{
struct epoch_tracker et;
struct ifaddr *ifa;
struct ifnet *ifp = pr->ndpr_ifp;
struct nd_prefix *opr;
char ip6buf[INET6_ADDRSTRLEN];
int error;
ND6_ONLINK_LOCK_ASSERT();
ND6_UNLOCK_ASSERT();
if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0)
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.
*/
ND6_RLOCK();
LIST_FOREACH(opr, &V_nd_prefix, ndpr_entry) {
if (opr == pr)
continue;
if ((opr->ndpr_stateflags & NDPRF_ONLINK) == 0)
continue;
if (!V_rt_add_addr_allfibs &&
opr->ndpr_ifp->if_fib != pr->ndpr_ifp->if_fib)
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)) {
ND6_RUNLOCK();
return (0);
}
}
ND6_RUNLOCK();
/*
* We prefer link-local addresses as the associated interface address.
*/
/* search for a link-local addr */
NET_EPOCH_ENTER(et);
ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
IN6_IFF_NOTREADY | IN6_IFF_ANYCAST);
if (ifa == NULL) {
/* XXX: freebsd does not have ifa_ifwithaf */
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family == AF_INET6) {
ifa_ref(ifa);
break;
}
}
/* should we care about ia6_flags? */
}
NET_EPOCH_EXIT(et);
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(ip6buf, &pr->ndpr_prefix.sin6_addr),
pr->ndpr_plen, if_name(ifp)));
return (0);
}
error = nd6_prefix_onlink_rtrequest(pr, ifa);
if (ifa != NULL)
ifa_free(ifa);
return (error);
}
int
nd6_prefix_offlink(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;
char ip6buf[INET6_ADDRSTRLEN];
uint64_t genid;
int fibnum, maxfib, a_failure;
ND6_ONLINK_LOCK_ASSERT();
ND6_UNLOCK_ASSERT();
if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0)
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));
if (V_rt_add_addr_allfibs) {
fibnum = 0;
maxfib = rt_numfibs;
} else {
fibnum = ifp->if_fib;
maxfib = fibnum + 1;
}
a_failure = 0;
for (; fibnum < maxfib; fibnum++) {
rt = NULL;
error = in6_rtrequest(RTM_DELETE, (struct sockaddr *)&sa6, NULL,
(struct sockaddr *)&mask6, 0, &rt, fibnum);
if (error == 0) {
/* report the route deletion to the routing socket. */
if (rt != NULL)
nd6_rtmsg(RTM_DELETE, rt);
} else {
/* Save last error to return, see rtinit(). */
a_failure = error;
}
if (rt != NULL) {
RTFREE(rt);
}
}
error = a_failure;
a_failure = 1;
if (error == 0) {
pr->ndpr_stateflags &= ~NDPRF_ONLINK;
/*
* 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.
*/
ND6_RLOCK();
restart:
LIST_FOREACH(opr, &V_nd_prefix, ndpr_entry) {
/*
* KAME specific: detached prefixes should not be
* on-link.
*/
if (opr == pr || (opr->ndpr_stateflags &
(NDPRF_ONLINK | 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;
genid = V_nd6_list_genid;
ND6_RUNLOCK();
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(ip6buf,
&opr->ndpr_prefix.sin6_addr),
opr->ndpr_plen, if_name(ifp),
if_name(opr->ndpr_ifp), e));
} else
a_failure = 0;
ND6_RLOCK();
if (genid != V_nd6_list_genid)
goto restart;
}
}
ND6_RUNLOCK();
} 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(ip6buf, &sa6.sin6_addr), pr->ndpr_plen,
if_name(ifp), error));
}
if (a_failure)
lltable_prefix_free(AF_INET6, (struct sockaddr *)&sa6,
(struct sockaddr *)&mask6, LLE_STATIC);
return (error);
}
static struct in6_ifaddr *
in6_ifadd(struct nd_prefixctl *pr, int mcast)
{
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;
int updateflags;
char ip6buf[INET6_ADDRSTRLEN];
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 an 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;
/* prefixlen + ifidlen must be equal to 128 */
plen0 = in6_mask2len(&ib->ia_prefixmask.sin6_addr, NULL);
if (prefixlen != plen0) {
ifa_free(ifa);
nd6log((LOG_INFO, "in6_ifadd: wrong prefixlen for %s "
"(prefix=%d ifid=%d)\n",
if_name(ifp), prefixlen, 128 - plen0));
return NULL;
}
/* make ifaddr */
in6_prepare_ifra(&ifra, &pr->ndpr_prefix.sin6_addr, &mask);
IN6_MASK_ADDR(&ifra.ifra_addr.sin6_addr, &mask);
/* 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]);
ifa_free(ifa);
/* lifetimes. */
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 */
/*
* Make sure that we do not have this address already. This should
* usually not happen, but we can still see this case, e.g., if we
* have manually configured the exact address to be configured.
*/
ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp,
&ifra.ifra_addr.sin6_addr);
if (ifa != NULL) {
ifa_free(ifa);
/* this should be rare enough to make an explicit log */
log(LOG_INFO, "in6_ifadd: %s is already configured\n",
ip6_sprintf(ip6buf, &ifra.ifra_addr.sin6_addr));
return (NULL);
}
/*
* Allocate ifaddr structure, link into chain, etc.
* If we are going to create a new address upon receiving a multicasted
* RA, we need to impose a random delay before starting DAD.
* [draft-ietf-ipv6-rfc2462bis-02.txt, Section 5.4.2]
*/
updateflags = 0;
if (mcast)
updateflags |= IN6_IFAUPDATE_DADDELAY;
if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0) {
nd6log((LOG_ERR,
"in6_ifadd: failed to make ifaddr %s on %s (errno=%d)\n",
ip6_sprintf(ip6buf, &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);
/*
* XXXRW: Assumption of non-NULLness here might not be true with
* fine-grained locking -- should we validate it? Or just return
* earlier ifa rather than looking it up again?
*/
return (ia); /* this is always non-NULL and referenced. */
}
/*
* ia0 - corresponding public address
*/
int
in6_tmpifadd(const struct in6_ifaddr *ia0, int forcegen, int delay)
{
struct ifnet *ifp = ia0->ia_ifa.ifa_ifp;
struct in6_ifaddr *newia;
struct in6_aliasreq ifra;
int error;
int trylimit = 3; /* XXX: adhoc value */
int updateflags;
u_int32_t randid[2];
time_t vltime0, pltime0;
in6_prepare_ifra(&ifra, &ia0->ia_addr.sin6_addr,
&ia0->ia_prefixmask.sin6_addr);
ifra.ifra_addr = ia0->ia_addr; /* XXX: do we need this ? */
/* clear the old IFID */
IN6_MASK_ADDR(&ifra.ifra_addr.sin6_addr,
&ifra.ifra_prefixmask.sin6_addr);
again:
if (in6_get_tmpifid(ifp, (u_int8_t *)randid,
(const u_int8_t *)&ia0->ia_addr.sin6_addr.s6_addr[8], forcegen)) {
nd6log((LOG_NOTICE, "in6_tmpifadd: failed to find a good "
"random IFID\n"));
return (EINVAL);
}
ifra.ifra_addr.sin6_addr.s6_addr32[2] |=
(randid[0] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[2]));
ifra.ifra_addr.sin6_addr.s6_addr32[3] |=
(randid[1] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[3]));
/*
* in6_get_tmpifid() quite likely provided a unique interface ID.
* However, we may still have a chance to see collision, because
* there may be a time lag between generation of the ID and generation
* of the address. So, we'll do one more sanity check.
*/
if (in6_localip(&ifra.ifra_addr.sin6_addr) != 0) {
if (trylimit-- > 0) {
forcegen = 1;
goto again;
}
/* Give up. Something strange should have happened. */
nd6log((LOG_NOTICE, "in6_tmpifadd: failed to "
"find a unique random IFID\n"));
return (EEXIST);
}
/*
* The Valid Lifetime is the lower of the Valid Lifetime of the
* public address or TEMP_VALID_LIFETIME.
* The Preferred Lifetime is the lower of the Preferred Lifetime
* of the public address or TEMP_PREFERRED_LIFETIME -
* DESYNC_FACTOR.
*/
if (ia0->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
vltime0 = IFA6_IS_INVALID(ia0) ? 0 :
(ia0->ia6_lifetime.ia6t_vltime -
(time_uptime - ia0->ia6_updatetime));
if (vltime0 > V_ip6_temp_valid_lifetime)
vltime0 = V_ip6_temp_valid_lifetime;
} else
vltime0 = V_ip6_temp_valid_lifetime;
if (ia0->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
pltime0 = IFA6_IS_DEPRECATED(ia0) ? 0 :
(ia0->ia6_lifetime.ia6t_pltime -
(time_uptime - ia0->ia6_updatetime));
if (pltime0 > V_ip6_temp_preferred_lifetime - V_ip6_desync_factor){
pltime0 = V_ip6_temp_preferred_lifetime -
V_ip6_desync_factor;
}
} else
pltime0 = V_ip6_temp_preferred_lifetime - V_ip6_desync_factor;
ifra.ifra_lifetime.ia6t_vltime = vltime0;
ifra.ifra_lifetime.ia6t_pltime = pltime0;
/*
* A temporary address is created only if this calculated Preferred
* Lifetime is greater than REGEN_ADVANCE time units.
*/
if (ifra.ifra_lifetime.ia6t_pltime <= V_ip6_temp_regen_advance)
return (0);
/* XXX: scope zone ID? */
ifra.ifra_flags |= (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY);
/* allocate ifaddr structure, link into chain, etc. */
updateflags = 0;
if (delay)
updateflags |= IN6_IFAUPDATE_DADDELAY;
if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0)
return (error);
newia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
if (newia == NULL) { /* XXX: can it happen? */
nd6log((LOG_ERR,
"in6_tmpifadd: ifa update succeeded, but we got "
"no ifaddr\n"));
return (EINVAL); /* XXX */
}
newia->ia6_ndpr = ia0->ia6_ndpr;
newia->ia6_ndpr->ndpr_addrcnt++;
ifa_free(&newia->ia_ifa);
/*
* A newly added address might affect the status of other addresses.
* XXX: when the temporary address is generated with a new public
* address, the onlink check is redundant. However, it would be safe
* to do the check explicitly everywhere a new address is generated,
* and, in fact, we surely need the check when we create a new
* temporary address due to deprecation of an old temporary address.
*/
pfxlist_onlink_check();
return (0);
}
static int
in6_init_prefix_ltimes(struct nd_prefix *ndpr)
{
if (ndpr->ndpr_pltime == ND6_INFINITE_LIFETIME)
ndpr->ndpr_preferred = 0;
else
ndpr->ndpr_preferred = time_uptime + ndpr->ndpr_pltime;
if (ndpr->ndpr_vltime == ND6_INFINITE_LIFETIME)
ndpr->ndpr_expire = 0;
else
ndpr->ndpr_expire = time_uptime + ndpr->ndpr_vltime;
return 0;
}
static void
in6_init_address_ltimes(struct nd_prefix *new, struct in6_addrlifetime *lt6)
{
/* init ia6t_expire */
if (lt6->ia6t_vltime == ND6_INFINITE_LIFETIME)
lt6->ia6t_expire = 0;
else {
lt6->ia6t_expire = time_uptime;
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_uptime;
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(struct in6_addr *gateway, struct ifnet *ifp)
{
/* We'll care only link-local addresses */
if (!IN6_IS_ADDR_LINKLOCAL(gateway))
return;
/* XXX Do we really need to walk any but the default FIB? */
rt_foreach_fib_walk_del(AF_INET6, rt6_deleteroute, (void *)gateway);
}
static int
rt6_deleteroute(const struct rtentry *rt, void *arg)
{
#define SIN6(s) ((struct sockaddr_in6 *)s)
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 (1);
#undef SIN6
}
int
nd6_setdefaultiface(int ifindex)
{
int error = 0;
if (ifindex < 0 || V_if_index < ifindex)
return (EINVAL);
if (ifindex != 0 && !ifnet_byindex(ifindex))
return (EINVAL);
if (V_nd6_defifindex != ifindex) {
V_nd6_defifindex = ifindex;
if (V_nd6_defifindex > 0)
V_nd6_defifp = ifnet_byindex(V_nd6_defifindex);
else
V_nd6_defifp = NULL;
/*
* Our current implementation assumes one-to-one maping between
* interfaces and links, so it would be natural to use the
* default interface as the default link.
*/
scope6_setdefault(V_nd6_defifp);
}
return (error);
}
static int
nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS)
{
struct in6_defrouter d;
struct nd_defrouter *dr;
int error;
if (req->newptr != NULL)
return (EPERM);
error = sysctl_wire_old_buffer(req, 0);
if (error != 0)
return (error);
bzero(&d, sizeof(d));
d.rtaddr.sin6_family = AF_INET6;
d.rtaddr.sin6_len = sizeof(d.rtaddr);
ND6_RLOCK();
TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
d.rtaddr.sin6_addr = dr->rtaddr;
error = sa6_recoverscope(&d.rtaddr);
if (error != 0)
break;
d.flags = dr->raflags;
d.rtlifetime = dr->rtlifetime;
d.expire = dr->expire + (time_second - time_uptime);
d.if_index = dr->ifp->if_index;
error = SYSCTL_OUT(req, &d, sizeof(d));
if (error != 0)
break;
}
ND6_RUNLOCK();
return (error);
}
SYSCTL_DECL(_net_inet6_icmp6);
SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ND6_DRLIST, nd6_drlist,
CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
NULL, 0, nd6_sysctl_drlist, "S,in6_defrouter",
"NDP default router list");
bool
nd6_defrouter_list_empty(void)
{
return (TAILQ_EMPTY(&V_nd_defrouter));
}
void
nd6_defrouter_timer(void)
{
struct nd_defrouter *dr, *ndr;
struct nd_drhead drq;
TAILQ_INIT(&drq);
ND6_WLOCK();
TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr)
if (dr->expire && dr->expire < time_uptime)
defrouter_unlink(dr, &drq);
ND6_WUNLOCK();
while ((dr = TAILQ_FIRST(&drq)) != NULL) {
TAILQ_REMOVE(&drq, dr, dr_entry);
defrouter_del(dr);
}
}
/*
* Nuke default router list entries toward ifp.
* We defer removal of default router list entries that is installed in the
* routing table, in order to keep additional side effects as small as possible.
*/
void
nd6_defrouter_purge(struct ifnet *ifp)
{
struct nd_defrouter *dr, *ndr;
struct nd_drhead drq;
TAILQ_INIT(&drq);
ND6_WLOCK();
TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr) {
if (dr->installed)
continue;
if (dr->ifp == ifp)
defrouter_unlink(dr, &drq);
}
TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr) {
if (!dr->installed)
continue;
if (dr->ifp == ifp)
defrouter_unlink(dr, &drq);
}
ND6_WUNLOCK();
/* Delete the unlinked router objects. */
while ((dr = TAILQ_FIRST(&drq)) != NULL) {
TAILQ_REMOVE(&drq, dr, dr_entry);
defrouter_del(dr);
}
}
void
nd6_defrouter_flush_all(void)
{
struct nd_defrouter *dr;
struct nd_drhead drq;
TAILQ_INIT(&drq);
ND6_WLOCK();
while ((dr = TAILQ_FIRST(&V_nd_defrouter)) != NULL)
defrouter_unlink(dr, &drq);
ND6_WUNLOCK();
while ((dr = TAILQ_FIRST(&drq)) != NULL) {
TAILQ_REMOVE(&drq, dr, dr_entry);
defrouter_del(dr);
}
}
void
nd6_defrouter_init(void)
{
TAILQ_INIT(&V_nd_defrouter);
}
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