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freebsd-skq/sys/netinet6/nd6_nbr.c
ume 2f50cbb708 use arc4random. 
Obtained from:	KAME
2003-10-31 16:06:05 +00:00

1378 lines
35 KiB
C
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/* $FreeBSD$ */
/* $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 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 "opt_inet.h"
#include "opt_inet6.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/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>
#ifdef INET6
#include <netinet6/ipsec6.h>
#endif
#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 a 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 tlladdr;
union nd_opts ndopts;
struct sockaddr_dl *proxydl = NULL;
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, icmp6len,);
nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off);
#else
IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len);
if (nd_ns == NULL) {
icmp6stat.icp6s_tooshort++;
return;
}
#endif
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. */
if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL &&
/* don't check ifindex portion */
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;
int need_proxy;
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, 0);
need_proxy = (rt && (rt->rt_flags & RTF_ANNOUNCE) != 0 &&
rt->rt_gateway->sa_family == AF_LINK);
if (rt)
rtfree(rt);
if (need_proxy) {
/*
* 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);
}
}
}
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) |
(ip6_forwarding ? 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) |
(ip6_forwarding ? 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 a 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 in6_ifaddr *ia = NULL;
struct ip6_moptions im6o;
int icmp6len;
int maxlen;
caddr_t mac;
struct ifnet *outif = NULL;
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;
if (max_linkhdr + maxlen >= MCLBYTES) {
#ifdef DIAGNOSTIC
printf("nd6_ns_output: max_linkhdr + maxlen >= MCLBYTES "
"(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
#endif
return;
}
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;
if (daddr6)
ip6->ip6_dst = *daddr6;
else {
ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
ip6->ip6_dst.s6_addr16[1] = htons(ifp->if_index);
ip6->ip6_dst.s6_addr32[1] = 0;
ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3];
ip6->ip6_dst.s6_addr8[12] = 0xff;
}
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 a scope-wise match.
*/
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))
bcopy(saddr6, &ip6->ip6_src, sizeof(*saddr6));
else {
ia = in6_ifawithifp(ifp, &ip6->ip6_dst);
if (ia == NULL) {
m_freem(m);
return;
}
ip6->ip6_src = ia->ia_addr.sin6_addr;
}
} else {
/*
* Source address for DAD packet must always be IPv6
* unspecified address. (0::0)
*/
bzero(&ip6->ip6_src, sizeof(ip6->ip6_src));
}
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;
in6_clearscope(&nd_ns->nd_ns_target); /* XXX */
/*
* 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;
nd_ns->nd_ns_cksum =
in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
ip6_output(m, NULL, NULL, dad ? IPV6_DADOUTPUT : 0, &im6o, &outif, NULL);
if (outif) {
icmp6_ifstat_inc(outif, ifs6_out_msg);
icmp6_ifstat_inc(outif, ifs6_out_neighborsolicit);
}
icmp6stat.icp6s_outhist[ND_NEIGHBOR_SOLICIT]++;
}
/*
* 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;
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;
}
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, icmp6len,);
nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off);
#else
IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len);
if (nd_na == NULL) {
icmp6stat.icp6s_tooshort++;
return;
}
#endif
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 (IN6_IS_ADDR_MULTICAST(&daddr6))
if (is_solicited) {
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 (ln->ln_expire) {
ln->ln_expire = time_second +
ND_IFINFO(rt->rt_ifp)->reachable;
}
} else {
ln->ln_state = ND6_LLINFO_STALE;
ln->ln_expire = time_second + 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..
*/
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;
ln->ln_expire = time_second + nd6_gctimer;
}
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 (ln->ln_expire) {
ln->ln_expire = time_second +
ND_IFINFO(ifp)->reachable;
}
} else {
if (lladdr && llchange) {
ln->ln_state = ND6_LLINFO_STALE;
ln->ln_expire = time_second + nd6_gctimer;
}
}
}
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 = splnet();
dr = defrouter_lookup(in6, rt->rt_ifp);
if (dr)
defrtrlist_del(dr);
else if (!ip6_forwarding && ip6_accept_rtadv) {
/*
* 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 in6_ifaddr *ia = NULL;
struct ip6_moptions im6o;
int icmp6len;
int maxlen;
caddr_t mac = NULL;
struct ifnet *outif = NULL;
/* estimate the size of message */
maxlen = sizeof(*ip6) + sizeof(*nd_na);
maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
if (max_linkhdr + maxlen >= MCLBYTES) {
#ifdef DIAGNOSTIC
printf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES "
"(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
#endif
return;
}
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;
if (IN6_IS_ADDR_UNSPECIFIED(daddr6)) {
/* reply to DAD */
ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
ip6->ip6_dst.s6_addr16[1] = htons(ifp->if_index);
ip6->ip6_dst.s6_addr32[1] = 0;
ip6->ip6_dst.s6_addr32[2] = 0;
ip6->ip6_dst.s6_addr32[3] = IPV6_ADDR_INT32_ONE;
flags &= ~ND_NA_FLAG_SOLICITED;
} else
ip6->ip6_dst = *daddr6;
/*
* Select a source whose scope is the same as that of the dest.
*/
ia = in6_ifawithifp(ifp, &ip6->ip6_dst);
if (ia == NULL) {
m_freem(m);
return;
}
ip6->ip6_src = ia->ia_addr.sin6_addr;
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;
in6_clearscope(&nd_na->nd_na_target); /* XXX */
/*
* "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_short)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, &outif, NULL);
if (outif) {
icmp6_ifstat_inc(outif, ifs6_out_msg);
icmp6_ifstat_inc(outif, ifs6_out_neighboradvert);
}
icmp6stat.icp6s_outhist[ND_NEIGHBOR_ADVERT]++;
}
caddr_t
nd6_ifptomac(ifp)
struct ifnet *ifp;
{
switch (ifp->if_type) {
case IFT_ARCNET:
case IFT_ETHER:
case IFT_FDDI:
case IFT_IEEE1394:
#ifdef IFT_L2VLAN
case IFT_L2VLAN:
#endif
#ifdef IFT_IEEE80211
case IFT_IEEE80211:
#endif
case IFT_ISO88025:
return ((caddr_t)(ifp + 1));
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 */
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, 0);
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_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,
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 = splnet(); /* 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) {
/*
* We have more NS to go. Send NS packet for DAD.
*/
nd6_dad_ns_output(dp, ifa);
nd6_dad_starttimer(dp,
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) {
#if 0 /* 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 card/driver which
* loops back multicasts to myself.
*/
if (3 < dp->dad_count
&& dp->dad_ns_icount == dp->dad_count
&& dp->dad_na_icount == 0) {
log(LOG_INFO, "DAD questionable for %s(%s): "
"network card loops back multicast?\n",
ip6_sprintf(&ia->ia_addr.sin6_addr),
if_name(ifa->ifa_ifp));
/* XXX consider it a duplicate or not? */
/* duplicate++; */
} else {
/* We've seen NS, means DAD has failed. */
duplicate++;
}
#else
/* We've seen NS, means DAD has failed. */
duplicate++;
#endif
}
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_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;
struct ifnet *ifp;
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;
ifp = ifa->ifa_ifp;
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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