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NetBSD/sys/netinet6/nd6_nbr.c
drochner e1e8770b32 Give DAD a chance to succeed even if the network is "slightly broken" 
(in my case it as a switch set to "monitor" mode):
If we see an NS request for the address we are just probing for, for
three times the number of DAD packets we are supposed to send (the
"ip6.dad_count" sysctl variable), assume that these are our own packets
and let DAD succeed.
The code for this was mostly there, commented out. Just needed some fixes.
The "three times" is heuristic of course.
Being here, reset the "dad_ns_tcount" variable on a successful send;
otherwise we get strange interdependencies with user-settable variables
(ever tried to set ip6.dad_count to something >15?).
2005-02-02 20:56:27 +00:00

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/* $NetBSD: nd6_nbr.c,v 1.54 2005/02/02 20:56:27 drochner Exp $ */
/* $KAME: nd6_nbr.c,v 1.61 2001/02/10 16:06:14 jinmei 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_nbr.c,v 1.54 2005/02/02 20:56:27 drochner Exp $");
#include "opt_inet.h"
#include "opt_ipsec.h"
#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 <sys/queue.h>
#include <sys/callout.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/nd6.h>
#include <netinet/icmp6.h>
#ifdef IPSEC
#include <netinet6/ipsec.h>
#endif
#include <net/net_osdep.h>
#define SDL(s) ((struct sockaddr_dl *)s)
struct dadq;
static struct dadq *nd6_dad_find __P((struct ifaddr *));
static void nd6_dad_starttimer __P((struct dadq *, int));
static void nd6_dad_stoptimer __P((struct dadq *));
static void nd6_dad_timer __P((struct ifaddr *));
static void nd6_dad_ns_output __P((struct dadq *, struct ifaddr *));
static void nd6_dad_ns_input __P((struct ifaddr *));
static void nd6_dad_na_input __P((struct ifaddr *));
static int dad_ignore_ns = 0; /* ignore NS in DAD - specwise incorrect*/
static int dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */
/*
* Input an Neighbor Solicitation Message.
*
* Based on RFC 2461
* Based on RFC 2462 (duplicated address detection)
*/
void
nd6_ns_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_neighbor_solicit *nd_ns;
struct in6_addr saddr6 = ip6->ip6_src;
struct in6_addr daddr6 = ip6->ip6_dst;
struct in6_addr taddr6;
struct in6_addr myaddr6;
char *lladdr = NULL;
struct ifaddr *ifa;
int lladdrlen = 0;
int anycast = 0, proxy = 0, tentative = 0;
int router = ip6_forwarding;
int tlladdr;
union nd_opts ndopts;
struct sockaddr_dl *proxydl = NULL;
IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len);
if (nd_ns == NULL) {
icmp6stat.icp6s_tooshort++;
return;
}
ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */
taddr6 = nd_ns->nd_ns_target;
if (ip6->ip6_hlim != 255) {
nd6log((LOG_ERR,
"nd6_ns_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_UNSPECIFIED(&saddr6)) {
/* dst has to be solicited node multicast address. */
/* don't check ifindex portion */
if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL &&
daddr6.s6_addr32[1] == 0 &&
daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE &&
daddr6.s6_addr8[12] == 0xff) {
; /* good */
} else {
nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
"(wrong ip6 dst)\n"));
goto bad;
}
}
if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"));
goto bad;
}
if (IN6_IS_SCOPE_LINKLOCAL(&taddr6))
taddr6.s6_addr16[1] = htons(ifp->if_index);
icmp6len -= sizeof(*nd_ns);
nd6_option_init(nd_ns + 1, icmp6len, &ndopts);
if (nd6_options(&ndopts) < 0) {
nd6log((LOG_INFO,
"nd6_ns_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 (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) {
nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
"(link-layer address option)\n"));
goto bad;
}
/*
* Attaching target link-layer address to the NA?
* (RFC 2461 7.2.4)
*
* NS IP dst is unicast/anycast MUST NOT add
* NS IP dst is solicited-node multicast MUST add
*
* In implementation, we add target link-layer address by default.
* We do not add one in MUST NOT cases.
*/
#if 0 /* too much! */
ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &daddr6);
if (ifa && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST))
tlladdr = 0;
else
#endif
if (!IN6_IS_ADDR_MULTICAST(&daddr6))
tlladdr = 0;
else
tlladdr = 1;
/*
* Target address (taddr6) must be either:
* (1) Valid unicast/anycast address for my receiving interface,
* (2) Unicast address for which I'm offering proxy service, or
* (3) "tentative" address on which DAD is being performed.
*/
/* (1) and (3) check. */
ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
/* (2) check. */
if (!ifa) {
struct rtentry *rt;
struct sockaddr_in6 tsin6;
bzero(&tsin6, sizeof tsin6);
tsin6.sin6_len = sizeof(struct sockaddr_in6);
tsin6.sin6_family = AF_INET6;
tsin6.sin6_addr = taddr6;
rt = rtalloc1((struct sockaddr *)&tsin6, 0);
if (rt && (rt->rt_flags & RTF_ANNOUNCE) != 0 &&
rt->rt_gateway->sa_family == AF_LINK) {
/*
* proxy NDP for single entry
*/
ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
if (ifa) {
proxy = 1;
proxydl = SDL(rt->rt_gateway);
router = 0; /* XXX */
}
}
if (rt)
rtfree(rt);
}
if (!ifa) {
/*
* We've got an NS packet, and we don't have that adddress
* assigned for us. We MUST silently ignore it.
* See RFC2461 7.2.3.
*/
goto freeit;
}
myaddr6 = *IFA_IN6(ifa);
anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST;
tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE;
if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED)
goto freeit;
if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
"(if %d, NS packet %d)\n",
ip6_sprintf(&taddr6), ifp->if_addrlen, lladdrlen - 2));
goto bad;
}
if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
ip6_sprintf(&saddr6)));
goto freeit;
}
/*
* We have neighbor solicitation packet, with target address equals to
* one of my tentative address.
*
* src addr how to process?
* --- ---
* multicast of course, invalid (rejected in ip6_input)
* unicast somebody is doing address resolution -> ignore
* unspec dup address detection
*
* The processing is defined in RFC 2462.
*/
if (tentative) {
/*
* If source address is unspecified address, it is for
* duplicated address detection.
*
* If not, the packet is for addess resolution;
* silently ignore it.
*/
if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
nd6_dad_ns_input(ifa);
goto freeit;
}
/*
* If the source address is unspecified address, entries must not
* be created or updated.
* It looks that sender is performing DAD. Output NA toward
* all-node multicast address, to tell the sender that I'm using
* the address.
* S bit ("solicited") must be zero.
*/
if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
saddr6 = in6addr_linklocal_allnodes;
saddr6.s6_addr16[1] = htons(ifp->if_index);
nd6_na_output(ifp, &saddr6, &taddr6,
((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
(router ? ND_NA_FLAG_ROUTER : 0),
tlladdr, (struct sockaddr *)proxydl);
goto freeit;
}
nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_NEIGHBOR_SOLICIT, 0);
nd6_na_output(ifp, &saddr6, &taddr6,
((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
(router ? ND_NA_FLAG_ROUTER : 0) | ND_NA_FLAG_SOLICITED,
tlladdr, (struct sockaddr *)proxydl);
freeit:
m_freem(m);
return;
bad:
nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", ip6_sprintf(&saddr6)));
nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", ip6_sprintf(&daddr6)));
nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", ip6_sprintf(&taddr6)));
icmp6stat.icp6s_badns++;
m_freem(m);
}
/*
* Output an Neighbor Solicitation Message. Caller specifies:
* - ICMP6 header source IP6 address
* - ND6 header target IP6 address
* - ND6 header source datalink address
*
* Based on RFC 2461
* Based on RFC 2462 (duplicated address detection)
*/
void
nd6_ns_output(ifp, daddr6, taddr6, ln, dad)
struct ifnet *ifp;
const struct in6_addr *daddr6, *taddr6;
struct llinfo_nd6 *ln; /* for source address determination */
int dad; /* duplicated address detection */
{
struct mbuf *m;
struct ip6_hdr *ip6;
struct nd_neighbor_solicit *nd_ns;
struct sockaddr_in6 src_sa, dst_sa;
struct ip6_moptions im6o;
int icmp6len;
int maxlen;
caddr_t mac;
struct route_in6 ro;
bzero(&ro, sizeof(ro));
if (IN6_IS_ADDR_MULTICAST(taddr6))
return;
/* estimate the size of message */
maxlen = sizeof(*ip6) + sizeof(*nd_ns);
maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
#ifdef DIAGNOSTIC
if (max_linkhdr + maxlen >= MCLBYTES) {
printf("nd6_ns_output: max_linkhdr + maxlen >= MCLBYTES "
"(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
panic("nd6_ns_output: insufficient MCLBYTES");
/* NOTREACHED */
}
#endif
MGETHDR(m, M_DONTWAIT, MT_DATA);
if (m && max_linkhdr + maxlen >= MHLEN) {
MCLGET(m, M_DONTWAIT);
if ((m->m_flags & M_EXT) == 0) {
m_free(m);
m = NULL;
}
}
if (m == NULL)
return;
m->m_pkthdr.rcvif = NULL;
if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
m->m_flags |= M_MCAST;
im6o.im6o_multicast_ifp = ifp;
im6o.im6o_multicast_hlim = 255;
im6o.im6o_multicast_loop = 0;
}
icmp6len = sizeof(*nd_ns);
m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */
/* fill neighbor solicitation packet */
ip6 = mtod(m, struct ip6_hdr *);
ip6->ip6_flow = 0;
ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
ip6->ip6_vfc |= IPV6_VERSION;
/* ip6->ip6_plen will be set later */
ip6->ip6_nxt = IPPROTO_ICMPV6;
ip6->ip6_hlim = 255;
/* determine the source and destination addresses */
bzero(&src_sa, sizeof(src_sa));
bzero(&dst_sa, sizeof(dst_sa));
src_sa.sin6_family = dst_sa.sin6_family = AF_INET6;
src_sa.sin6_len = dst_sa.sin6_len = sizeof(struct sockaddr_in6);
if (daddr6)
dst_sa.sin6_addr = *daddr6;
else {
dst_sa.sin6_addr.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
dst_sa.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
dst_sa.sin6_addr.s6_addr32[1] = 0;
dst_sa.sin6_addr.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
dst_sa.sin6_addr.s6_addr32[3] = taddr6->s6_addr32[3];
dst_sa.sin6_addr.s6_addr8[12] = 0xff;
}
ip6->ip6_dst = dst_sa.sin6_addr;
if (!dad) {
/*
* RFC2461 7.2.2:
* "If the source address of the packet prompting the
* solicitation is the same as one of the addresses assigned
* to the outgoing interface, that address SHOULD be placed
* in the IP Source Address of the outgoing solicitation.
* Otherwise, any one of the addresses assigned to the
* interface should be used."
*
* We use the source address for the prompting packet
* (saddr6), if:
* - saddr6 is given from the caller (by giving "ln"), and
* - saddr6 belongs to the outgoing interface.
* Otherwise, we perform the source address selection as usual.
*/
struct ip6_hdr *hip6; /* hold ip6 */
struct in6_addr *saddr6;
if (ln && ln->ln_hold) {
hip6 = mtod(ln->ln_hold, struct ip6_hdr *);
/* XXX pullup? */
if (sizeof(*hip6) < ln->ln_hold->m_len)
saddr6 = &hip6->ip6_src;
else
saddr6 = NULL;
} else
saddr6 = NULL;
if (saddr6 && in6ifa_ifpwithaddr(ifp, saddr6))
src_sa.sin6_addr = *saddr6;
else {
struct in6_addr *src0;
int error;
bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa));
src0 = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL,
&error);
if (src0 == NULL) {
nd6log((LOG_DEBUG,
"nd6_ns_output: source can't be "
"determined: dst=%s, error=%d\n",
ip6_sprintf(&dst_sa.sin6_addr), error));
goto bad;
}
src_sa.sin6_addr = *src0;
}
} else {
/*
* Source address for DAD packet must always be IPv6
* unspecified address. (0::0)
* We actually don't have to 0-clear the address (we did it
* above), but we do so here explicitly to make the intention
* clearer.
*/
bzero(&src_sa.sin6_addr, sizeof(src_sa.sin6_addr));
}
ip6->ip6_src = src_sa.sin6_addr;
nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
nd_ns->nd_ns_code = 0;
nd_ns->nd_ns_reserved = 0;
nd_ns->nd_ns_target = *taddr6;
if (IN6_IS_SCOPE_LINKLOCAL(&nd_ns->nd_ns_target))
nd_ns->nd_ns_target.s6_addr16[1] = 0;
/*
* Add source link-layer address option.
*
* spec implementation
* --- ---
* DAD packet MUST NOT do not add the option
* there's no link layer address:
* impossible do not add the option
* there's link layer address:
* Multicast NS MUST add one add the option
* Unicast NS SHOULD add one add the option
*/
if (!dad && (mac = nd6_ifptomac(ifp))) {
int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
/* 8 byte alignments... */
optlen = (optlen + 7) & ~7;
m->m_pkthdr.len += optlen;
m->m_len += optlen;
icmp6len += optlen;
bzero((caddr_t)nd_opt, optlen);
nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
nd_opt->nd_opt_len = optlen >> 3;
bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
}
ip6->ip6_plen = htons((u_int16_t)icmp6len);
nd_ns->nd_ns_cksum = 0;
nd_ns->nd_ns_cksum =
in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
ip6_output(m, NULL, &ro, dad ? IPV6_UNSPECSRC : 0,
&im6o, (struct socket *)NULL, NULL);
icmp6_ifstat_inc(ifp, ifs6_out_msg);
icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
icmp6stat.icp6s_outhist[ND_NEIGHBOR_SOLICIT]++;
if (ro.ro_rt) { /* we don't cache this route. */
RTFREE(ro.ro_rt);
}
return;
bad:
if (ro.ro_rt) {
RTFREE(ro.ro_rt);
}
m_freem(m);
return;
}
/*
* Neighbor advertisement input handling.
*
* Based on RFC 2461
* Based on RFC 2462 (duplicated address detection)
*
* the following items are not implemented yet:
* - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
* - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
*/
void
nd6_na_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_neighbor_advert *nd_na;
#if 0
struct in6_addr saddr6 = ip6->ip6_src;
#endif
struct in6_addr daddr6 = ip6->ip6_dst;
struct in6_addr taddr6;
int flags;
int is_router;
int is_solicited;
int is_override;
char *lladdr = NULL;
int lladdrlen = 0;
struct ifaddr *ifa;
struct llinfo_nd6 *ln;
struct rtentry *rt;
struct sockaddr_dl *sdl;
union nd_opts ndopts;
if (ip6->ip6_hlim != 255) {
nd6log((LOG_ERR,
"nd6_na_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;
}
IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len);
if (nd_na == NULL) {
icmp6stat.icp6s_tooshort++;
return;
}
taddr6 = nd_na->nd_na_target;
flags = nd_na->nd_na_flags_reserved;
is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
if (IN6_IS_SCOPE_LINKLOCAL(&taddr6))
taddr6.s6_addr16[1] = htons(ifp->if_index);
if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
nd6log((LOG_ERR,
"nd6_na_input: invalid target address %s\n",
ip6_sprintf(&taddr6)));
goto bad;
}
if (is_solicited && IN6_IS_ADDR_MULTICAST(&daddr6)) {
nd6log((LOG_ERR,
"nd6_na_input: a solicited adv is multicasted\n"));
goto bad;
}
icmp6len -= sizeof(*nd_na);
nd6_option_init(nd_na + 1, icmp6len, &ndopts);
if (nd6_options(&ndopts) < 0) {
nd6log((LOG_INFO,
"nd6_na_input: invalid ND option, ignored\n"));
/* nd6_options have incremented stats */
goto freeit;
}
if (ndopts.nd_opts_tgt_lladdr) {
lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
}
ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
/*
* Target address matches one of my interface address.
*
* If my address is tentative, this means that there's somebody
* already using the same address as mine. This indicates DAD failure.
* This is defined in RFC 2462.
*
* Otherwise, process as defined in RFC 2461.
*/
if (ifa
&& (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
nd6_dad_na_input(ifa);
goto freeit;
}
/* Just for safety, maybe unnecessary. */
if (ifa) {
log(LOG_ERR,
"nd6_na_input: duplicate IP6 address %s\n",
ip6_sprintf(&taddr6));
goto freeit;
}
if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
"(if %d, NA packet %d)\n", ip6_sprintf(&taddr6),
ifp->if_addrlen, lladdrlen - 2));
goto bad;
}
/*
* If no neighbor cache entry is found, NA SHOULD silently be
* discarded.
*/
rt = nd6_lookup(&taddr6, 0, ifp);
if ((rt == NULL) ||
((ln = (struct llinfo_nd6 *)rt->rt_llinfo) == NULL) ||
((sdl = SDL(rt->rt_gateway)) == NULL))
goto freeit;
if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
/*
* If the link-layer has address, and no lladdr option came,
* discard the packet.
*/
if (ifp->if_addrlen && !lladdr)
goto freeit;
/*
* Record link-layer address, and update the state.
*/
sdl->sdl_alen = ifp->if_addrlen;
bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen);
if (is_solicited) {
ln->ln_state = ND6_LLINFO_REACHABLE;
ln->ln_byhint = 0;
if (!ND6_LLINFO_PERMANENT(ln)) {
nd6_llinfo_settimer(ln,
(long)ND_IFINFO(rt->rt_ifp)->reachable * hz);
}
} else {
ln->ln_state = ND6_LLINFO_STALE;
nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz);
}
if ((ln->ln_router = is_router) != 0) {
/*
* This means a router's state has changed from
* non-reachable to probably reachable, and might
* affect the status of associated prefixes..
*/
pfxlist_onlink_check();
}
} else {
int llchange;
/*
* Check if the link-layer address has changed or not.
*/
if (!lladdr)
llchange = 0;
else {
if (sdl->sdl_alen) {
if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen))
llchange = 1;
else
llchange = 0;
} else
llchange = 1;
}
/*
* This is VERY complex. Look at it with care.
*
* override solicit lladdr llchange action
* (L: record lladdr)
*
* 0 0 n -- (2c)
* 0 0 y n (2b) L
* 0 0 y y (1) REACHABLE->STALE
* 0 1 n -- (2c) *->REACHABLE
* 0 1 y n (2b) L *->REACHABLE
* 0 1 y y (1) REACHABLE->STALE
* 1 0 n -- (2a)
* 1 0 y n (2a) L
* 1 0 y y (2a) L *->STALE
* 1 1 n -- (2a) *->REACHABLE
* 1 1 y n (2a) L *->REACHABLE
* 1 1 y y (2a) L *->REACHABLE
*/
if (!is_override && (lladdr && llchange)) { /* (1) */
/*
* If state is REACHABLE, make it STALE.
* no other updates should be done.
*/
if (ln->ln_state == ND6_LLINFO_REACHABLE) {
ln->ln_state = ND6_LLINFO_STALE;
nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz);
}
goto freeit;
} else if (is_override /* (2a) */
|| (!is_override && (lladdr && !llchange)) /* (2b) */
|| !lladdr) { /* (2c) */
/*
* Update link-local address, if any.
*/
if (lladdr) {
sdl->sdl_alen = ifp->if_addrlen;
bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen);
}
/*
* If solicited, make the state REACHABLE.
* If not solicited and the link-layer address was
* changed, make it STALE.
*/
if (is_solicited) {
ln->ln_state = ND6_LLINFO_REACHABLE;
ln->ln_byhint = 0;
if (!ND6_LLINFO_PERMANENT(ln)) {
nd6_llinfo_settimer(ln,
(long)ND_IFINFO(ifp)->reachable * hz);
}
} else {
if (lladdr && llchange) {
ln->ln_state = ND6_LLINFO_STALE;
nd6_llinfo_settimer(ln,
(long)nd6_gctimer * hz);
}
}
}
if (ln->ln_router && !is_router) {
/*
* The peer dropped the router flag.
* Remove the sender from the Default Router List and
* update the Destination Cache entries.
*/
struct nd_defrouter *dr;
struct in6_addr *in6;
int s;
in6 = &((struct sockaddr_in6 *)rt_key(rt))->sin6_addr;
/*
* Lock to protect the default router list.
* XXX: this might be unnecessary, since this function
* is only called under the network software interrupt
* context. However, we keep it just for safety.
*/
s = splsoftnet();
dr = defrouter_lookup(in6, rt->rt_ifp);
if (dr)
defrtrlist_del(dr);
else if (!ip6_forwarding) {
/*
* Even if the neighbor is not in the default
* router list, the neighbor may be used
* as a next hop for some destinations
* (e.g. redirect case). So we must
* call rt6_flush explicitly.
*/
rt6_flush(&ip6->ip6_src, rt->rt_ifp);
}
splx(s);
}
ln->ln_router = is_router;
}
rt->rt_flags &= ~RTF_REJECT;
ln->ln_asked = 0;
if (ln->ln_hold) {
/*
* we assume ifp is not a loopback here, so just set the 2nd
* argument as the 1st one.
*/
nd6_output(ifp, ifp, ln->ln_hold,
(struct sockaddr_in6 *)rt_key(rt), rt);
ln->ln_hold = NULL;
}
freeit:
m_freem(m);
return;
bad:
icmp6stat.icp6s_badna++;
m_freem(m);
}
/*
* Neighbor advertisement output handling.
*
* Based on RFC 2461
*
* the following items are not implemented yet:
* - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
* - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
*/
void
nd6_na_output(ifp, daddr6, taddr6, flags, tlladdr, sdl0)
struct ifnet *ifp;
const struct in6_addr *daddr6, *taddr6;
u_long flags;
int tlladdr; /* 1 if include target link-layer address */
struct sockaddr *sdl0; /* sockaddr_dl (= proxy NA) or NULL */
{
struct mbuf *m;
struct ip6_hdr *ip6;
struct nd_neighbor_advert *nd_na;
struct ip6_moptions im6o;
struct sockaddr_in6 dst_sa;
struct in6_addr *src0;
int icmp6len, maxlen, error;
caddr_t mac;
struct route_in6 ro;
mac = NULL;
bzero(&ro, sizeof(ro));
/* estimate the size of message */
maxlen = sizeof(*ip6) + sizeof(*nd_na);
maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
#ifdef DIAGNOSTIC
if (max_linkhdr + maxlen >= MCLBYTES) {
printf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES "
"(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
panic("nd6_na_output: insufficient MCLBYTES");
/* NOTREACHED */
}
#endif
MGETHDR(m, M_DONTWAIT, MT_DATA);
if (m && max_linkhdr + maxlen >= MHLEN) {
MCLGET(m, M_DONTWAIT);
if ((m->m_flags & M_EXT) == 0) {
m_free(m);
m = NULL;
}
}
if (m == NULL)
return;
m->m_pkthdr.rcvif = NULL;
if (IN6_IS_ADDR_MULTICAST(daddr6)) {
m->m_flags |= M_MCAST;
im6o.im6o_multicast_ifp = ifp;
im6o.im6o_multicast_hlim = 255;
im6o.im6o_multicast_loop = 0;
}
icmp6len = sizeof(*nd_na);
m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */
/* fill neighbor advertisement packet */
ip6 = mtod(m, struct ip6_hdr *);
ip6->ip6_flow = 0;
ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
ip6->ip6_vfc |= IPV6_VERSION;
ip6->ip6_nxt = IPPROTO_ICMPV6;
ip6->ip6_hlim = 255;
bzero(&dst_sa, sizeof(dst_sa));
dst_sa.sin6_len = sizeof(struct sockaddr_in6);
dst_sa.sin6_family = AF_INET6;
dst_sa.sin6_addr = *daddr6;
if (IN6_IS_ADDR_UNSPECIFIED(daddr6)) {
/* reply to DAD */
dst_sa.sin6_addr.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
dst_sa.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
dst_sa.sin6_addr.s6_addr32[1] = 0;
dst_sa.sin6_addr.s6_addr32[2] = 0;
dst_sa.sin6_addr.s6_addr32[3] = IPV6_ADDR_INT32_ONE;
flags &= ~ND_NA_FLAG_SOLICITED;
}
ip6->ip6_dst = dst_sa.sin6_addr;
/*
* Select a source whose scope is the same as that of the dest.
*/
bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa));
src0 = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, &error);
if (src0 == NULL) {
nd6log((LOG_DEBUG, "nd6_na_output: source can't be "
"determined: dst=%s, error=%d\n",
ip6_sprintf(&dst_sa.sin6_addr), error));
goto bad;
}
ip6->ip6_src = *src0;
nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
nd_na->nd_na_code = 0;
nd_na->nd_na_target = *taddr6;
if (IN6_IS_SCOPE_LINKLOCAL(&nd_na->nd_na_target))
nd_na->nd_na_target.s6_addr16[1] = 0;
/*
* "tlladdr" indicates NS's condition for adding tlladdr or not.
* see nd6_ns_input() for details.
* Basically, if NS packet is sent to unicast/anycast addr,
* target lladdr option SHOULD NOT be included.
*/
if (tlladdr) {
/*
* sdl0 != NULL indicates proxy NA. If we do proxy, use
* lladdr in sdl0. If we are not proxying (sending NA for
* my address) use lladdr configured for the interface.
*/
if (sdl0 == NULL)
mac = nd6_ifptomac(ifp);
else if (sdl0->sa_family == AF_LINK) {
struct sockaddr_dl *sdl;
sdl = (struct sockaddr_dl *)sdl0;
if (sdl->sdl_alen == ifp->if_addrlen)
mac = LLADDR(sdl);
}
}
if (tlladdr && mac) {
int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
/* roundup to 8 bytes alignment! */
optlen = (optlen + 7) & ~7;
m->m_pkthdr.len += optlen;
m->m_len += optlen;
icmp6len += optlen;
bzero((caddr_t)nd_opt, optlen);
nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
nd_opt->nd_opt_len = optlen >> 3;
bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
} else
flags &= ~ND_NA_FLAG_OVERRIDE;
ip6->ip6_plen = htons((u_int16_t)icmp6len);
nd_na->nd_na_flags_reserved = flags;
nd_na->nd_na_cksum = 0;
nd_na->nd_na_cksum =
in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len);
ip6_output(m, NULL, NULL, 0, &im6o, (struct socket *)NULL, NULL);
icmp6_ifstat_inc(ifp, ifs6_out_msg);
icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert);
icmp6stat.icp6s_outhist[ND_NEIGHBOR_ADVERT]++;
if (ro.ro_rt) { /* we don't cache this route. */
RTFREE(ro.ro_rt);
}
return;
bad:
if (ro.ro_rt) {
RTFREE(ro.ro_rt);
}
m_freem(m);
return;
}
caddr_t
nd6_ifptomac(ifp)
struct ifnet *ifp;
{
switch (ifp->if_type) {
case IFT_ARCNET:
case IFT_ETHER:
case IFT_FDDI:
case IFT_IEEE1394:
case IFT_PROPVIRTUAL:
case IFT_L2VLAN:
case IFT_IEEE80211:
return LLADDR(ifp->if_sadl);
default:
return NULL;
}
}
TAILQ_HEAD(dadq_head, dadq);
struct dadq {
TAILQ_ENTRY(dadq) dad_list;
struct ifaddr *dad_ifa;
int dad_count; /* max NS to send, standard case */
int dad_maxcount; /* max NS to send, loopback detection */
int dad_ns_tcount; /* # of trials to send NS */
int dad_ns_ocount; /* NS sent so far */
int dad_ns_icount;
int dad_na_icount;
struct callout dad_timer_ch;
};
static struct dadq_head dadq;
static int dad_init = 0;
static struct dadq *
nd6_dad_find(ifa)
struct ifaddr *ifa;
{
struct dadq *dp;
for (dp = dadq.tqh_first; dp; dp = dp->dad_list.tqe_next) {
if (dp->dad_ifa == ifa)
return dp;
}
return NULL;
}
static void
nd6_dad_starttimer(dp, ticks)
struct dadq *dp;
int ticks;
{
callout_reset(&dp->dad_timer_ch, ticks,
(void (*) __P((void *)))nd6_dad_timer, (void *)dp->dad_ifa);
}
static void
nd6_dad_stoptimer(dp)
struct dadq *dp;
{
callout_stop(&dp->dad_timer_ch);
}
/*
* Start Duplicated Address Detection (DAD) for specified interface address.
*/
void
nd6_dad_start(ifa, tick)
struct ifaddr *ifa;
int *tick; /* minimum delay ticks for IFF_UP event */
{
struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
struct dadq *dp;
if (!dad_init) {
TAILQ_INIT(&dadq);
dad_init++;
}
/*
* If we don't need DAD, don't do it.
* There are several cases:
* - DAD is disabled (ip6_dad_count == 0)
* - the interface address is anycast
*/
if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) {
log(LOG_DEBUG,
"nd6_dad_start: called with non-tentative address "
"%s(%s)\n",
ip6_sprintf(&ia->ia_addr.sin6_addr),
ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
return;
}
if (ia->ia6_flags & IN6_IFF_ANYCAST) {
ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
return;
}
if (!ip6_dad_count) {
ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
return;
}
if (!ifa->ifa_ifp)
panic("nd6_dad_start: ifa->ifa_ifp == NULL");
if (!(ifa->ifa_ifp->if_flags & IFF_UP))
return;
if (nd6_dad_find(ifa) != NULL) {
/* DAD already in progress */
return;
}
dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT);
if (dp == NULL) {
log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
"%s(%s)\n",
ip6_sprintf(&ia->ia_addr.sin6_addr),
ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
return;
}
bzero(dp, sizeof(*dp));
callout_init(&dp->dad_timer_ch);
TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list);
nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
ip6_sprintf(&ia->ia_addr.sin6_addr)));
/*
* Send NS packet for DAD, ip6_dad_count times.
* Note that we must delay the first transmission, if this is the
* first packet to be sent from the interface after interface
* (re)initialization.
*/
dp->dad_ifa = ifa;
IFAREF(ifa); /* just for safety */
dp->dad_count = ip6_dad_count;
dp->dad_maxcount = 3 * ip6_dad_count; /* XXX sysctl??? */
dp->dad_ns_icount = dp->dad_na_icount = 0;
dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
if (tick == NULL) {
nd6_dad_ns_output(dp, ifa);
nd6_dad_starttimer(dp,
(long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
} else {
int ntick;
if (*tick == 0)
ntick = arc4random() % (MAX_RTR_SOLICITATION_DELAY * hz);
else
ntick = *tick + arc4random() % (hz / 2);
*tick = ntick;
nd6_dad_starttimer(dp, ntick);
}
}
/*
* terminate DAD unconditionally. used for address removals.
*/
void
nd6_dad_stop(ifa)
struct ifaddr *ifa;
{
struct dadq *dp;
if (!dad_init)
return;
dp = nd6_dad_find(ifa);
if (!dp) {
/* DAD wasn't started yet */
return;
}
nd6_dad_stoptimer(dp);
TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list);
free(dp, M_IP6NDP);
dp = NULL;
IFAFREE(ifa);
}
static void
nd6_dad_timer(ifa)
struct ifaddr *ifa;
{
int s;
struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
struct dadq *dp;
s = splsoftnet(); /* XXX */
/* Sanity check */
if (ia == NULL) {
log(LOG_ERR, "nd6_dad_timer: called with null parameter\n");
goto done;
}
dp = nd6_dad_find(ifa);
if (dp == NULL) {
log(LOG_ERR, "nd6_dad_timer: DAD structure not found\n");
goto done;
}
if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
log(LOG_ERR, "nd6_dad_timer: called with duplicated address "
"%s(%s)\n",
ip6_sprintf(&ia->ia_addr.sin6_addr),
ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
goto done;
}
if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
log(LOG_ERR, "nd6_dad_timer: called with non-tentative address "
"%s(%s)\n",
ip6_sprintf(&ia->ia_addr.sin6_addr),
ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
goto done;
}
/* timeouted with IFF_{RUNNING,UP} check */
if (dp->dad_ns_tcount > dad_maxtry) {
nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n",
if_name(ifa->ifa_ifp)));
TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list);
free(dp, M_IP6NDP);
dp = NULL;
IFAFREE(ifa);
goto done;
}
/* Need more checks? */
if ((dp->dad_ns_ocount < dp->dad_count)
|| ((dp->dad_ns_ocount < dp->dad_maxcount)
&& (dp->dad_ns_icount == dp->dad_ns_ocount))) {
/*
* We have more NS to go. Send NS packet for DAD.
*/
nd6_dad_ns_output(dp, ifa);
nd6_dad_starttimer(dp,
(long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
} else {
/*
* We have transmitted sufficient number of DAD packets.
* See what we've got.
*/
int duplicate;
duplicate = 0;
if (dp->dad_na_icount) {
/*
* the check is in nd6_dad_na_input(),
* but just in case
*/
duplicate++;
}
if (dp->dad_ns_icount) { /* heuristics */
/*
* if
* - we have sent many DAD NS, and
* - the number of NS we sent equals to the
* number of NS we've got, and
* - we've got no NA
* we may have a faulty network which
* loops back multicasts to myself.
*/
if (dp->dad_ns_ocount == dp->dad_maxcount
&& dp->dad_ns_icount == dp->dad_ns_ocount
&& dp->dad_na_icount == 0) {
log(LOG_INFO, "DAD questionable for %s(%s): "
"network loops back multicast?\n",
ip6_sprintf(&ia->ia_addr.sin6_addr),
if_name(ifa->ifa_ifp));
} else {
/* DAD has failed. */
duplicate++;
}
}
if (duplicate) {
/* (*dp) will be freed in nd6_dad_duplicated() */
dp = NULL;
nd6_dad_duplicated(ifa);
} else {
/*
* We are done with DAD. No NA came, no NS came.
* duplicated address found.
*/
ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
nd6log((LOG_DEBUG,
"%s: DAD complete for %s - no duplicates found\n",
if_name(ifa->ifa_ifp),
ip6_sprintf(&ia->ia_addr.sin6_addr)));
TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list);
free(dp, M_IP6NDP);
dp = NULL;
IFAFREE(ifa);
}
}
done:
splx(s);
}
void
nd6_dad_duplicated(ifa)
struct ifaddr *ifa;
{
struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
struct dadq *dp;
dp = nd6_dad_find(ifa);
if (dp == NULL) {
log(LOG_ERR, "nd6_dad_duplicated: DAD structure not found\n");
return;
}
log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
"NS in/out=%d/%d, NA in=%d\n",
if_name(ifa->ifa_ifp), ip6_sprintf(&ia->ia_addr.sin6_addr),
dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount);
ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
ia->ia6_flags |= IN6_IFF_DUPLICATED;
/* We are done with DAD, with duplicated address found. (failure) */
nd6_dad_stoptimer(dp);
log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
if_name(ifa->ifa_ifp), ip6_sprintf(&ia->ia_addr.sin6_addr));
log(LOG_ERR, "%s: manual intervention required\n",
if_name(ifa->ifa_ifp));
TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list);
free(dp, M_IP6NDP);
dp = NULL;
IFAFREE(ifa);
}
static void
nd6_dad_ns_output(dp, ifa)
struct dadq *dp;
struct ifaddr *ifa;
{
struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
struct ifnet *ifp = ifa->ifa_ifp;
dp->dad_ns_tcount++;
if ((ifp->if_flags & IFF_UP) == 0) {
#if 0
printf("%s: interface down?\n", if_name(ifp));
#endif
return;
}
if ((ifp->if_flags & IFF_RUNNING) == 0) {
#if 0
printf("%s: interface not running?\n", if_name(ifp));
#endif
return;
}
dp->dad_ns_tcount = 0;
dp->dad_ns_ocount++;
nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1);
}
static void
nd6_dad_ns_input(ifa)
struct ifaddr *ifa;
{
struct in6_ifaddr *ia;
const struct in6_addr *taddr6;
struct dadq *dp;
int duplicate;
if (!ifa)
panic("ifa == NULL in nd6_dad_ns_input");
ia = (struct in6_ifaddr *)ifa;
taddr6 = &ia->ia_addr.sin6_addr;
duplicate = 0;
dp = nd6_dad_find(ifa);
/* Quickhack - completely ignore DAD NS packets */
if (dad_ignore_ns) {
nd6log((LOG_INFO,
"nd6_dad_ns_input: ignoring DAD NS packet for "
"address %s(%s)\n", ip6_sprintf(taddr6),
if_name(ifa->ifa_ifp)));
return;
}
/*
* if I'm yet to start DAD, someone else started using this address
* first. I have a duplicate and you win.
*/
if (!dp || dp->dad_ns_ocount == 0)
duplicate++;
/* XXX more checks for loopback situation - see nd6_dad_timer too */
if (duplicate) {
dp = NULL; /* will be freed in nd6_dad_duplicated() */
nd6_dad_duplicated(ifa);
} else {
/*
* not sure if I got a duplicate.
* increment ns count and see what happens.
*/
if (dp)
dp->dad_ns_icount++;
}
}
static void
nd6_dad_na_input(ifa)
struct ifaddr *ifa;
{
struct dadq *dp;
if (!ifa)
panic("ifa == NULL in nd6_dad_na_input");
dp = nd6_dad_find(ifa);
if (dp)
dp->dad_na_icount++;
/* remove the address. */
nd6_dad_duplicated(ifa);
}
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