/
nd6_nbr.c
1375 lines (1227 loc) · 35.7 KB
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nd6_nbr.c
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/* $OpenBSD: nd6_nbr.c,v 1.129 2019/11/29 16:41:02 nayden 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/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/ioctl.h>
#include <sys/syslog.h>
#include <sys/queue.h>
#include <sys/timeout.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 <netinet/in.h>
#include <netinet/if_ether.h>
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/nd6.h>
#include <netinet/icmp6.h>
#include "carp.h"
#if NCARP > 0
#include <netinet/ip_carp.h>
#endif
TAILQ_HEAD(dadq_head, dadq);
struct dadq {
TAILQ_ENTRY(dadq) dad_list;
struct ifaddr *dad_ifa;
int dad_count; /* max NS to send */
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 timeout dad_timer_ch;
};
struct dadq *nd6_dad_find(struct ifaddr *);
void nd6_dad_starttimer(struct dadq *, int);
void nd6_dad_stoptimer(struct dadq *);
void nd6_dad_timer(void *);
void nd6_dad_ns_output(struct dadq *, struct ifaddr *);
void nd6_dad_ns_input(struct ifaddr *);
void nd6_dad_duplicated(struct dadq *);
int nd6_isneighbor(const struct ifnet *, const struct in6_addr *);
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(struct mbuf *m, int off, int icmp6len)
{
struct ifnet *ifp;
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 = NULL;
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;
char addr[INET6_ADDRSTRLEN], addr0[INET6_ADDRSTRLEN];
ifp = if_get(m->m_pkthdr.ph_ifidx);
if (ifp == NULL)
goto freeit;
IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len);
if (nd_ns == NULL) {
icmp6stat_inc(icp6s_tooshort);
if_put(ifp);
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,
inet_ntop(AF_INET6, &ip6->ip6_src, addr, sizeof(addr)),
inet_ntop(AF_INET6, &ip6->ip6_dst, addr0, sizeof(addr0)),
ifp->if_xname));
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;
}
} else {
/*
* Make sure the source address is from a neighbor's address.
*/
if (!nd6_isneighbor(ifp, &saddr6)) {
nd6log((LOG_INFO, "nd6_ns_input: "
"NS packet from non-neighbor\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_EMBED(&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 = &in6ifa_ifpwithaddr(ifp, &daddr6)->ia_ifa;
if (ifa && (ifatoia6(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 = &in6ifa_ifpwithaddr(ifp, &taddr6)->ia_ifa;
#if NCARP > 0
if (ifp->if_type == IFT_CARP && ifa && !carp_iamatch(ifp))
ifa = NULL;
#endif
/* (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 = rtalloc(sin6tosa(&tsin6), 0, m->m_pkthdr.ph_rtableid);
if (rt && (rt->rt_flags & RTF_ANNOUNCE) != 0 &&
rt->rt_gateway->sa_family == AF_LINK) {
/*
* proxy NDP for single entry
*/
ifa = &in6ifa_ifpforlinklocal(ifp, IN6_IFF_TENTATIVE|
IN6_IFF_DUPLICATED|IN6_IFF_ANYCAST)->ia_ifa;
if (ifa) {
proxy = 1;
proxydl = satosdl(rt->rt_gateway);
router = 0; /* XXX */
}
}
if (rt)
rtfree(rt);
}
if (!ifa) {
/*
* We've got an NS packet, and we don't have that address
* assigned for us. We MUST silently ignore it.
* See RFC2461 7.2.3.
*/
goto freeit;
}
myaddr6 = *IFA_IN6(ifa);
anycast = ifatoia6(ifa)->ia6_flags & IN6_IFF_ANYCAST;
tentative = ifatoia6(ifa)->ia6_flags & IN6_IFF_TENTATIVE;
if (ifatoia6(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",
inet_ntop(AF_INET6, &taddr6, addr, sizeof(addr)),
ifp->if_addrlen, lladdrlen - 2));
goto bad;
}
if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
log(LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
inet_ntop(AF_INET6, &saddr6, addr, sizeof(addr)));
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 address 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, sdltosa(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, sdltosa(proxydl));
freeit:
m_freem(m);
if_put(ifp);
return;
bad:
nd6log((LOG_ERR, "nd6_ns_input: src=%s\n",
inet_ntop(AF_INET6, &saddr6, addr, sizeof(addr))));
nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n",
inet_ntop(AF_INET6, &daddr6, addr, sizeof(addr))));
nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n",
inet_ntop(AF_INET6, &taddr6, addr, sizeof(addr))));
icmp6stat_inc(icp6s_badns);
m_freem(m);
if_put(ifp);
}
/*
* 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)
*
* ln - for source address determination
* dad - duplicated address detection
*/
void
nd6_ns_output(struct ifnet *ifp, struct in6_addr *daddr6,
struct in6_addr *taddr6, struct llinfo_nd6 *ln, int dad)
{
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;
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("%s: max_linkhdr + maxlen >= MCLBYTES "
"(%d + %d > %d)\n", __func__, max_linkhdr, maxlen, MCLBYTES);
panic("%s: insufficient MCLBYTES", __func__);
/* 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.ph_ifidx = 0;
m->m_pkthdr.ph_rtableid = ifp->if_rdomain;
if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
m->m_flags |= M_MCAST;
im6o.im6o_ifidx = ifp->if_index;
im6o.im6o_hlim = 255;
im6o.im6o_loop = 0;
}
icmp6len = sizeof(*nd_ns);
m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
m_align(m, maxlen);
/* 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 and
* - if taddr is link local saddr6 must be link local as well
* 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 *);
if (sizeof(*hip6) <= ln->ln_hold->m_len) {
saddr6 = &hip6->ip6_src;
if (saddr6 && IN6_IS_ADDR_LINKLOCAL(taddr6) &&
!IN6_IS_ADDR_LINKLOCAL(saddr6))
saddr6 = NULL;
} else
saddr6 = NULL;
} else
saddr6 = NULL;
if (saddr6 && in6ifa_ifpwithaddr(ifp, saddr6))
src_sa.sin6_addr = *saddr6;
else {
struct rtentry *rt;
rt = rtalloc(sin6tosa(&dst_sa), RT_RESOLVE,
m->m_pkthdr.ph_rtableid);
if (!rtisvalid(rt)) {
char addr[INET6_ADDRSTRLEN];
nd6log((LOG_DEBUG,
"%s: source can't be determined: dst=%s\n",
__func__, inet_ntop(AF_INET6,
&dst_sa.sin6_addr, addr, sizeof(addr))));
rtfree(rt);
goto bad;
}
src_sa.sin6_addr =
ifatoia6(rt->rt_ifa)->ia_addr.sin6_addr;
rtfree(rt);
}
} 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_EMBED(&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_short)icmp6len);
nd_ns->nd_ns_cksum = 0;
m->m_pkthdr.csum_flags |= M_ICMP_CSUM_OUT;
ip6_output(m, NULL, NULL, dad ? IPV6_UNSPECSRC : 0, &im6o, NULL);
icmp6stat_inc(icp6s_outhist + ND_NEIGHBOR_SOLICIT);
return;
bad:
m_freem(m);
}
/*
* 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(struct mbuf *m, int off, int icmp6len)
{
struct ifnet *ifp;
struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
struct nd_neighbor_advert *nd_na;
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 = NULL;
struct sockaddr_dl *sdl;
union nd_opts ndopts;
char addr[INET6_ADDRSTRLEN], addr0[INET6_ADDRSTRLEN];
NET_ASSERT_LOCKED();
ifp = if_get(m->m_pkthdr.ph_ifidx);
if (ifp == NULL)
goto freeit;
if (ip6->ip6_hlim != 255) {
nd6log((LOG_ERR,
"nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
ip6->ip6_hlim,
inet_ntop(AF_INET6, &ip6->ip6_src, addr, sizeof(addr)),
inet_ntop(AF_INET6, &ip6->ip6_dst, addr0, sizeof(addr0)),
ifp->if_xname));
goto bad;
}
IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len);
if (nd_na == NULL) {
icmp6stat_inc(icp6s_tooshort);
if_put(ifp);
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_EMBED(&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",
inet_ntop(AF_INET6, &taddr6, addr, sizeof(addr))));
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 (IN6_IS_ADDR_MULTICAST(&daddr6) && !ndopts.nd_opts_tgt_lladdr) {
nd6log((LOG_INFO,
"nd6_na_input: multicast adv without TLLA\n"));
goto bad;
}
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 = &in6ifa_ifpwithaddr(ifp, &taddr6)->ia_ifa;
/*
* 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 && (ifatoia6(ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
struct dadq *dp;
dp = nd6_dad_find(ifa);
if (dp) {
dp->dad_na_icount++;
/* remove the address. */
nd6_dad_duplicated(dp);
}
goto freeit;
}
if (ifa) {
#if NCARP > 0
/*
* Ignore NAs silently for carp addresses if we're not
* the CARP master.
*/
if (ifp->if_type == IFT_CARP && !carp_iamatch(ifp))
goto freeit;
#endif
log(LOG_ERR,
"nd6_na_input: duplicate IP6 address %s\n",
inet_ntop(AF_INET6, &taddr6, addr, sizeof(addr)));
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",
inet_ntop(AF_INET6, &taddr6, addr, sizeof(addr)),
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, ifp->if_rdomain);
if ((rt == NULL) ||
((ln = (struct llinfo_nd6 *)rt->rt_llinfo) == NULL) ||
((sdl = satosdl(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;
/* Notify userland that a new ND entry is reachable. */
rtm_send(rt, RTM_RESOLVE, 0, ifp->if_rdomain);
if (!ND6_LLINFO_PERMANENT(ln)) {
nd6_llinfo_settimer(ln,
ND_IFINFO(ifp)->reachable);
}
} else {
ln->ln_state = ND6_LLINFO_STALE;
nd6_llinfo_settimer(ln, nd6_gctimer);
}
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..
*/
if ((rt->rt_flags & RTF_LLINFO) == 0)
goto freeit; /* ln is gone */
}
} 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, nd6_gctimer);
}
goto freeit;
} else if (is_override /* (2a) */
|| (!is_override && (lladdr && !llchange)) /* (2b) */
|| !lladdr) { /* (2c) */
/*
* Update link-local address, if any.
*/
if (llchange) {
log(LOG_INFO, "ndp info overwritten for %s "
"by %s on %s\n",
inet_ntop(AF_INET6, &taddr6,
addr, sizeof(addr)),
ether_sprintf(lladdr), ifp->if_xname);
}
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,
ND_IFINFO(ifp)->reachable);
}
} else {
if (lladdr && llchange) {
ln->ln_state = ND6_LLINFO_STALE;
nd6_llinfo_settimer(ln, nd6_gctimer);
}
}
}
if (ln->ln_router && !is_router) {
if (!ip6_forwarding) {
/*
* 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, ifp);
}
}
ln->ln_router = is_router;
}
rt->rt_flags &= ~RTF_REJECT;
ln->ln_asked = 0;
if (ln->ln_hold) {
struct mbuf *n = ln->ln_hold;
ln->ln_hold = NULL;
/*
* we assume ifp is not a loopback here, so just set the 2nd
* argument as the 1st one.
*/
ifp->if_output(ifp, n, rt_key(rt), rt);
if (ln->ln_hold == n) {
/* n is back in ln_hold. Discard. */
m_freem(ln->ln_hold);
ln->ln_hold = NULL;
}
}
freeit:
rtfree(rt);
m_freem(m);
if_put(ifp);
return;
bad:
icmp6stat_inc(icp6s_badna);
m_freem(m);
if_put(ifp);
}
/*
* 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)
*
* tlladdr - 1 if include target link-layer address
* sdl0 - sockaddr_dl (= proxy NA) or NULL
*/
void
nd6_na_output(struct ifnet *ifp, struct in6_addr *daddr6,
struct in6_addr *taddr6, u_long flags, int tlladdr,
struct sockaddr *sdl0)
{
struct mbuf *m;
struct rtentry *rt = NULL;
struct ip6_hdr *ip6;
struct nd_neighbor_advert *nd_na;
struct ip6_moptions im6o;
struct sockaddr_in6 dst_sa;
int icmp6len, maxlen;
caddr_t mac = NULL;
#if NCARP > 0
/* Do not send NAs for carp addresses if we're not the CARP master. */
if (ifp->if_type == IFT_CARP && !carp_iamatch(ifp))
return;
#endif
/* 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("%s: max_linkhdr + maxlen >= MCLBYTES "
"(%d + %d > %d)\n", __func__, max_linkhdr, maxlen, MCLBYTES);
panic("%s: insufficient MCLBYTES", __func__);
/* 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.ph_rtableid = ifp->if_rdomain;
if (IN6_IS_ADDR_MULTICAST(daddr6)) {
m->m_flags |= M_MCAST;
im6o.im6o_ifidx = ifp->if_index;
im6o.im6o_hlim = 255;
im6o.im6o_loop = 0;
}
icmp6len = sizeof(*nd_na);
m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
m_align(m, maxlen);
/* 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.
*/
rt = rtalloc(sin6tosa(&dst_sa), RT_RESOLVE, ifp->if_rdomain);
if (!rtisvalid(rt)) {
char addr[INET6_ADDRSTRLEN];
nd6log((LOG_DEBUG, "%s: source can't be determined: dst=%s\n",
__func__, inet_ntop(AF_INET6, &dst_sa.sin6_addr, addr,
sizeof(addr))));
rtfree(rt);
goto bad;
}
ip6->ip6_src = ifatoia6(rt->rt_ifa)->ia_addr.sin6_addr;
rtfree(rt);
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_EMBED(&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 = satosdl(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;