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src/sys/netinet6/icmp6.c

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/* $OpenBSD: icmp6.c,v 1.251 2023/12/03 20:36:24 bluhm Exp $ */
/* $KAME: icmp6.c,v 1.217 2001/06/20 15:03:29 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.
*/
/*
* Copyright (c) 1982, 1986, 1988, 1993
* The Regents of the University of California. 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 University 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 REGENTS 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 REGENTS 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.
*
* @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94
*/
#include "carp.h"
#include "pf.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/sysctl.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/route.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
#include <netinet6/mld6_var.h>
#include <netinet/in_pcb.h>
#include <netinet6/nd6.h>
#include <netinet6/ip6protosw.h>
#if NCARP > 0
#include <netinet/ip_carp.h>
#endif
#if NPF > 0
#include <net/pfvar.h>
#endif
struct cpumem *icmp6counters;
extern int icmp6errppslim;
static int icmp6errpps_count = 0;
static struct timeval icmp6errppslim_last;
/*
* List of callbacks to notify when Path MTU changes are made.
*/
struct icmp6_mtudisc_callback {
LIST_ENTRY(icmp6_mtudisc_callback) mc_list;
void (*mc_func)(struct sockaddr_in6 *, u_int);
};
LIST_HEAD(, icmp6_mtudisc_callback) icmp6_mtudisc_callbacks =
LIST_HEAD_INITIALIZER(icmp6_mtudisc_callbacks);
struct rttimer_queue icmp6_mtudisc_timeout_q;
/* XXX do these values make any sense? */
static int icmp6_mtudisc_hiwat = 1280;
static int icmp6_mtudisc_lowat = 256;
/*
* keep track of # of redirect routes.
*/
struct rttimer_queue icmp6_redirect_timeout_q;
void icmp6_errcount(int, int);
int icmp6_ratelimit(const struct in6_addr *, const int, const int);
const char *icmp6_redirect_diag(struct in6_addr *, struct in6_addr *,
struct in6_addr *);
int icmp6_notify_error(struct mbuf *, int, int, int);
void icmp6_mtudisc_timeout(struct rtentry *, u_int);
void
icmp6_init(void)
{
mld6_init();
rt_timer_queue_init(&icmp6_mtudisc_timeout_q, ip6_mtudisc_timeout,
&icmp6_mtudisc_timeout);
rt_timer_queue_init(&icmp6_redirect_timeout_q, icmp6_redirtimeout,
NULL);
icmp6counters = counters_alloc(icp6s_ncounters);
}
void
icmp6_errcount(int type, int code)
{
enum icmp6stat_counters c = icp6s_ounknown;
switch (type) {
case ICMP6_DST_UNREACH:
switch (code) {
case ICMP6_DST_UNREACH_NOROUTE:
c = icp6s_odst_unreach_noroute;
break;
case ICMP6_DST_UNREACH_ADMIN:
c = icp6s_odst_unreach_admin;
break;
case ICMP6_DST_UNREACH_BEYONDSCOPE:
c = icp6s_odst_unreach_beyondscope;
break;
case ICMP6_DST_UNREACH_ADDR:
c = icp6s_odst_unreach_addr;
break;
case ICMP6_DST_UNREACH_NOPORT:
c = icp6s_odst_unreach_noport;
break;
}
break;
case ICMP6_PACKET_TOO_BIG:
c = icp6s_opacket_too_big;
break;
case ICMP6_TIME_EXCEEDED:
switch (code) {
case ICMP6_TIME_EXCEED_TRANSIT:
c = icp6s_otime_exceed_transit;
break;
case ICMP6_TIME_EXCEED_REASSEMBLY:
c = icp6s_otime_exceed_reassembly;
break;
}
break;
case ICMP6_PARAM_PROB:
switch (code) {
case ICMP6_PARAMPROB_HEADER:
c = icp6s_oparamprob_header;
break;
case ICMP6_PARAMPROB_NEXTHEADER:
c = icp6s_oparamprob_nextheader;
break;
case ICMP6_PARAMPROB_OPTION:
c = icp6s_oparamprob_option;
break;
}
break;
case ND_REDIRECT:
c = icp6s_oredirect;
break;
}
icmp6stat_inc(c);
}
/*
* Register a Path MTU Discovery callback.
*/
void
icmp6_mtudisc_callback_register(void (*func)(struct sockaddr_in6 *, u_int))
{
struct icmp6_mtudisc_callback *mc;
LIST_FOREACH(mc, &icmp6_mtudisc_callbacks, mc_list) {
if (mc->mc_func == func)
return;
}
mc = malloc(sizeof(*mc), M_PCB, M_NOWAIT);
if (mc == NULL)
panic("%s", __func__);
mc->mc_func = func;
LIST_INSERT_HEAD(&icmp6_mtudisc_callbacks, mc, mc_list);
}
struct mbuf *
icmp6_do_error(struct mbuf *m, int type, int code, int param)
{
struct ip6_hdr *oip6, *nip6;
struct icmp6_hdr *icmp6;
u_int preplen;
int off;
int nxt;
icmp6stat_inc(icp6s_error);
/* count per-type-code statistics */
icmp6_errcount(type, code);
if (m->m_len < sizeof(struct ip6_hdr)) {
m = m_pullup(m, sizeof(struct ip6_hdr));
if (m == NULL)
return (NULL);
}
oip6 = mtod(m, struct ip6_hdr *);
/*
* If the destination address of the erroneous packet is a multicast
* address, or the packet was sent using link-layer multicast,
* we should basically suppress sending an error (RFC 2463, Section
* 2.4).
* We have two exceptions (the item e.2 in that section):
* - the Packet Too Big message can be sent for path MTU discovery.
* - the Parameter Problem Message that can be allowed an icmp6 error
* in the option type field. This check has been done in
* ip6_unknown_opt(), so we can just check the type and code.
*/
if ((m->m_flags & (M_BCAST|M_MCAST) ||
IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
(type != ICMP6_PACKET_TOO_BIG &&
(type != ICMP6_PARAM_PROB ||
code != ICMP6_PARAMPROB_OPTION)))
goto freeit;
/*
* RFC 2463, 2.4 (e.5): source address check.
* XXX: the case of anycast source?
*/
if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
goto freeit;
/*
* If we are about to send ICMPv6 against ICMPv6 error/redirect,
* don't do it.
*/
nxt = -1;
off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
if (off >= 0 && nxt == IPPROTO_ICMPV6) {
struct icmp6_hdr *icp;
IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
sizeof(*icp));
if (icp == NULL) {
icmp6stat_inc(icp6s_tooshort);
return (NULL);
}
if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
icp->icmp6_type == ND_REDIRECT) {
/*
* ICMPv6 error
* Special case: for redirect (which is
* informational) we must not send icmp6 error.
*/
icmp6stat_inc(icp6s_canterror);
goto freeit;
} else {
/* ICMPv6 informational - send the error */
}
}
else {
/* non-ICMPv6 - send the error */
}
oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
/* Finally, do rate limitation check. */
if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
icmp6stat_inc(icp6s_toofreq);
goto freeit;
}
/*
* OK, ICMP6 can be generated.
*/
if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
M_PREPEND(m, preplen, M_DONTWAIT);
if (m && m->m_len < preplen)
m = m_pullup(m, preplen);
if (m == NULL) {
nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
return (NULL);
}
nip6 = mtod(m, struct ip6_hdr *);
nip6->ip6_src = oip6->ip6_src;
nip6->ip6_dst = oip6->ip6_dst;
if (IN6_IS_SCOPE_EMBED(&oip6->ip6_src))
oip6->ip6_src.s6_addr16[1] = 0;
if (IN6_IS_SCOPE_EMBED(&oip6->ip6_dst))
oip6->ip6_dst.s6_addr16[1] = 0;
icmp6 = (struct icmp6_hdr *)(nip6 + 1);
icmp6->icmp6_type = type;
icmp6->icmp6_code = code;
icmp6->icmp6_pptr = htonl((u_int32_t)param);
/*
* icmp6_reflect() is designed to be in the input path.
* icmp6_error() can be called from both input and output path,
* and if we are in output path rcvif could contain bogus value.
* clear m->m_pkthdr.ph_ifidx for safety, we should have enough
* scope information in ip header (nip6).
*/
m->m_pkthdr.ph_ifidx = 0;
icmp6stat_inc(icp6s_outhist + type);
return (m);
freeit:
/*
* If we can't tell whether or not we can generate ICMP6, free it.
*/
return (m_freem(m));
}
/*
* Generate an error packet of type error in response to bad IP6 packet.
*/
void
icmp6_error(struct mbuf *m, int type, int code, int param)
{
struct mbuf *n;
n = icmp6_do_error(m, type, code, param);
if (n != NULL) {
/* header order: IPv6 - ICMPv6 */
if (!icmp6_reflect(&n, sizeof(struct ip6_hdr), NULL))
ip6_send(n);
}
}
/*
* Process a received ICMP6 message.
*/
int
icmp6_input(struct mbuf **mp, int *offp, int proto, int af)
{
#if NCARP > 0
struct ifnet *ifp;
#endif
struct mbuf *m = *mp, *n;
struct ip6_hdr *ip6, *nip6;
struct icmp6_hdr *icmp6, *nicmp6;
int off = *offp;
int icmp6len = m->m_pkthdr.len - off;
int code, sum, noff;
char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN];
/*
* Locate icmp6 structure in mbuf, and check
* that not corrupted and of at least minimum length
*/
ip6 = mtod(m, struct ip6_hdr *);
if (icmp6len < sizeof(struct icmp6_hdr)) {
icmp6stat_inc(icp6s_tooshort);
goto freeit;
}
/*
* calculate the checksum
*/
IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
if (icmp6 == NULL) {
icmp6stat_inc(icp6s_tooshort);
return IPPROTO_DONE;
}
code = icmp6->icmp6_code;
if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
nd6log((LOG_ERR,
"ICMP6 checksum error(%d|%x) %s\n",
icmp6->icmp6_type, sum,
inet_ntop(AF_INET6, &ip6->ip6_src, src, sizeof(src))));
icmp6stat_inc(icp6s_checksum);
goto freeit;
}
#if NPF > 0
if (m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) {
switch (icmp6->icmp6_type) {
/*
* These ICMP6 types map to other connections. They must be
* delivered to pr_ctlinput() also for diverted connections.
*/
case ICMP6_DST_UNREACH:
case ICMP6_PACKET_TOO_BIG:
case ICMP6_TIME_EXCEEDED:
case ICMP6_PARAM_PROB:
/*
* Do not use the divert-to property of the TCP or UDP
* rule when doing the PCB lookup for the raw socket.
*/
m->m_pkthdr.pf.flags &=~ PF_TAG_DIVERTED;
break;
default:
goto raw;
}
}
#endif /* NPF */
#if NCARP > 0
ifp = if_get(m->m_pkthdr.ph_ifidx);
if (ifp == NULL)
goto freeit;
if (icmp6->icmp6_type == ICMP6_ECHO_REQUEST &&
carp_lsdrop(ifp, m, AF_INET6, ip6->ip6_src.s6_addr32,
ip6->ip6_dst.s6_addr32, 1)) {
if_put(ifp);
goto freeit;
}
if_put(ifp);
#endif
icmp6stat_inc(icp6s_inhist + icmp6->icmp6_type);
switch (icmp6->icmp6_type) {
case ICMP6_DST_UNREACH:
switch (code) {
case ICMP6_DST_UNREACH_NOROUTE:
code = PRC_UNREACH_NET;
break;
case ICMP6_DST_UNREACH_ADMIN:
code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
break;
case ICMP6_DST_UNREACH_ADDR:
code = PRC_HOSTDEAD;
break;
case ICMP6_DST_UNREACH_BEYONDSCOPE:
/* I mean "source address was incorrect." */
code = PRC_PARAMPROB;
break;
case ICMP6_DST_UNREACH_NOPORT:
code = PRC_UNREACH_PORT;
break;
default:
goto badcode;
}
goto deliver;
case ICMP6_PACKET_TOO_BIG:
/* MTU is checked in icmp6_mtudisc_update. */
code = PRC_MSGSIZE;
/*
* Updating the path MTU will be done after examining
* intermediate extension headers.
*/
goto deliver;
case ICMP6_TIME_EXCEEDED:
switch (code) {
case ICMP6_TIME_EXCEED_TRANSIT:
code = PRC_TIMXCEED_INTRANS;
break;
case ICMP6_TIME_EXCEED_REASSEMBLY:
code = PRC_TIMXCEED_REASS;
break;
default:
goto badcode;
}
goto deliver;
case ICMP6_PARAM_PROB:
switch (code) {
case ICMP6_PARAMPROB_NEXTHEADER:
code = PRC_UNREACH_PROTOCOL;
break;
case ICMP6_PARAMPROB_HEADER:
case ICMP6_PARAMPROB_OPTION:
code = PRC_PARAMPROB;
break;
default:
goto badcode;
}
goto deliver;
case ICMP6_ECHO_REQUEST:
if (code != 0)
goto badcode;
/*
* Copy mbuf to send to two data paths: userland socket(s),
* and to the querier (echo reply).
* m: a copy for socket, n: a copy for querier
*/
if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
/* Give up local */
n = m;
m = *mp = NULL;
goto deliverecho;
}
/*
* If the first mbuf is shared, or the first mbuf is too short,
* copy the first part of the data into a fresh mbuf.
* Otherwise, we will wrongly overwrite both copies.
*/
if ((n->m_flags & M_EXT) != 0 ||
n->m_len < off + sizeof(struct icmp6_hdr)) {
struct mbuf *n0 = n;
const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
/*
* Prepare an internal mbuf. m_pullup() doesn't
* always copy the length we specified.
*/
if (maxlen >= MCLBYTES) {
/* Give up remote */
m_freem(n0);
break;
}
MGETHDR(n, M_DONTWAIT, n0->m_type);
if (n && maxlen >= MHLEN) {
MCLGET(n, M_DONTWAIT);
if ((n->m_flags & M_EXT) == 0) {
m_free(n);
n = NULL;
}
}
if (n == NULL) {
/* Give up local */
m_freem(n0);
n = m;
m = *mp = NULL;
goto deliverecho;
}
M_MOVE_PKTHDR(n, n0);
/*
* Copy IPv6 and ICMPv6 only.
*/
nip6 = mtod(n, struct ip6_hdr *);
bcopy(ip6, nip6, sizeof(struct ip6_hdr));
nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
noff = sizeof(struct ip6_hdr);
n->m_len = noff + sizeof(struct icmp6_hdr);
/*
* Adjust mbuf. ip6_plen will be adjusted in
* ip6_output().
* n->m_pkthdr.len == n0->m_pkthdr.len at this point.
*/
n->m_pkthdr.len += noff + sizeof(struct icmp6_hdr);
n->m_pkthdr.len -= (off + sizeof(struct icmp6_hdr));
m_adj(n0, off + sizeof(struct icmp6_hdr));
n->m_next = n0;
} else {
deliverecho:
IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
sizeof(*nicmp6));
noff = off;
}
if (n) {
nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
nicmp6->icmp6_code = 0;
icmp6stat_inc(icp6s_reflect);
icmp6stat_inc(icp6s_outhist + ICMP6_ECHO_REPLY);
if (!icmp6_reflect(&n, noff, NULL))
ip6_send(n);
}
if (!m)
goto freeit;
break;
case ICMP6_ECHO_REPLY:
if (code != 0)
goto badcode;
break;
case MLD_LISTENER_QUERY:
case MLD_LISTENER_REPORT:
if (icmp6len < sizeof(struct mld_hdr))
goto badlen;
if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
/* give up local */
mld6_input(m, off);
m = NULL;
goto freeit;
}
mld6_input(n, off);
/* m stays. */
break;
case MLD_LISTENER_DONE:
if (icmp6len < sizeof(struct mld_hdr)) /* necessary? */
goto badlen;
break; /* nothing to be done in kernel */
case MLD_MTRACE_RESP:
case MLD_MTRACE:
/* XXX: these two are experimental. not officially defined. */
/* XXX: per-interface statistics? */
break; /* just pass it to applications */
case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */
/* IPv6 Node Information Queries are not supported */
break;
case ICMP6_WRUREPLY:
break;
case ND_ROUTER_SOLICIT:
case ND_ROUTER_ADVERT:
if (code != 0)
goto badcode;
if ((icmp6->icmp6_type == ND_ROUTER_SOLICIT && icmp6len <
sizeof(struct nd_router_solicit)) ||
(icmp6->icmp6_type == ND_ROUTER_ADVERT && icmp6len <
sizeof(struct nd_router_advert)))
goto badlen;
if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
/* give up local */
nd6_rtr_cache(m, off, icmp6len,
icmp6->icmp6_type);
m = NULL;
goto freeit;
}
nd6_rtr_cache(n, off, icmp6len, icmp6->icmp6_type);
/* m stays. */
break;
case ND_NEIGHBOR_SOLICIT:
if (code != 0)
goto badcode;
if (icmp6len < sizeof(struct nd_neighbor_solicit))
goto badlen;
if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
/* give up local */
nd6_ns_input(m, off, icmp6len);
m = NULL;
goto freeit;
}
nd6_ns_input(n, off, icmp6len);
/* m stays. */
break;
case ND_NEIGHBOR_ADVERT:
if (code != 0)
goto badcode;
if (icmp6len < sizeof(struct nd_neighbor_advert))
goto badlen;
if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
/* give up local */
nd6_na_input(m, off, icmp6len);
m = NULL;
goto freeit;
}
nd6_na_input(n, off, icmp6len);
/* m stays. */
break;
case ND_REDIRECT:
if (code != 0)
goto badcode;
if (icmp6len < sizeof(struct nd_redirect))
goto badlen;
if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
/* give up local */
icmp6_redirect_input(m, off);
m = NULL;
goto freeit;
}
icmp6_redirect_input(n, off);
/* m stays. */
break;
case ICMP6_ROUTER_RENUMBERING:
if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
code != ICMP6_ROUTER_RENUMBERING_RESULT)
goto badcode;
if (icmp6len < sizeof(struct icmp6_router_renum))
goto badlen;
break;
default:
nd6log((LOG_DEBUG,
"icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%u)\n",
icmp6->icmp6_type,
inet_ntop(AF_INET6, &ip6->ip6_src, src, sizeof(src)),
inet_ntop(AF_INET6, &ip6->ip6_dst, dst, sizeof(dst)),
m->m_pkthdr.ph_ifidx));
if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
/* ICMPv6 error: MUST deliver it by spec... */
code = PRC_NCMDS;
/* deliver */
} else {
/* ICMPv6 informational: MUST not deliver */
break;
}
deliver:
if (icmp6_notify_error(m, off, icmp6len, code)) {
/* In this case, m should've been freed. */
return (IPPROTO_DONE);
}
break;
badcode:
icmp6stat_inc(icp6s_badcode);
break;
badlen:
icmp6stat_inc(icp6s_badlen);
break;
}
#if NPF > 0
raw:
#endif
/* deliver the packet to appropriate sockets */
return rip6_input(mp, offp, proto, af);
freeit:
m_freem(m);
return IPPROTO_DONE;
}
int
icmp6_notify_error(struct mbuf *m, int off, int icmp6len, int code)
{
struct icmp6_hdr *icmp6;
struct ip6_hdr *eip6;
u_int32_t notifymtu;
struct sockaddr_in6 icmp6src, icmp6dst;
if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
icmp6stat_inc(icp6s_tooshort);
goto freeit;
}
IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
sizeof(*icmp6) + sizeof(struct ip6_hdr));
if (icmp6 == NULL) {
icmp6stat_inc(icp6s_tooshort);
return (-1);
}
eip6 = (struct ip6_hdr *)(icmp6 + 1);
/* Detect the upper level protocol */
{
void (*ctlfunc)(int, struct sockaddr *, u_int, void *);
u_int8_t nxt = eip6->ip6_nxt;
int eoff = off + sizeof(struct icmp6_hdr) +
sizeof(struct ip6_hdr);
struct ip6ctlparam ip6cp;
struct in6_addr *finaldst = NULL;
int icmp6type = icmp6->icmp6_type;
struct ip6_frag *fh;
struct ip6_rthdr *rth;
struct ip6_rthdr0 *rth0;
int rthlen;
while (1) { /* XXX: should avoid infinite loop explicitly? */
struct ip6_ext *eh;
switch (nxt) {
case IPPROTO_HOPOPTS:
case IPPROTO_DSTOPTS:
case IPPROTO_AH:
IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
eoff, sizeof(*eh));
if (eh == NULL) {
icmp6stat_inc(icp6s_tooshort);
return (-1);
}
if (nxt == IPPROTO_AH)
eoff += (eh->ip6e_len + 2) << 2;
else
eoff += (eh->ip6e_len + 1) << 3;
nxt = eh->ip6e_nxt;
break;
case IPPROTO_ROUTING:
/*
* When the erroneous packet contains a
* routing header, we should examine the
* header to determine the final destination.
* Otherwise, we can't properly update
* information that depends on the final
* destination (e.g. path MTU).
*/
IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
eoff, sizeof(*rth));
if (rth == NULL) {
icmp6stat_inc(icp6s_tooshort);
return (-1);
}
rthlen = (rth->ip6r_len + 1) << 3;
/*
* XXX: currently there is no
* officially defined type other
* than type-0.
* Note that if the segment left field
* is 0, all intermediate hops must
* have been passed.
*/
if (rth->ip6r_segleft &&
rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
int hops;
IP6_EXTHDR_GET(rth0,
struct ip6_rthdr0 *, m,
eoff, rthlen);
if (rth0 == NULL) {
icmp6stat_inc(icp6s_tooshort);
return (-1);
}
/* just ignore a bogus header */
if ((rth0->ip6r0_len % 2) == 0 &&
(hops = rth0->ip6r0_len/2))
finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
}
eoff += rthlen;
nxt = rth->ip6r_nxt;
break;
case IPPROTO_FRAGMENT:
IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
eoff, sizeof(*fh));
if (fh == NULL) {
icmp6stat_inc(icp6s_tooshort);
return (-1);
}
/*
* Data after a fragment header is meaningless
* unless it is the first fragment, but
* we'll go to the notify label for path MTU
* discovery.
*/
if (fh->ip6f_offlg & IP6F_OFF_MASK)
goto notify;
eoff += sizeof(struct ip6_frag);
nxt = fh->ip6f_nxt;
break;
default:
/*
* This case includes ESP and the No Next
* Header. In such cases going to the notify
* label does not have any meaning
* (i.e. ctlfunc will be NULL), but we go
* anyway since we might have to update
* path MTU information.
*/
goto notify;
}
}
notify:
IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
sizeof(*icmp6) + sizeof(struct ip6_hdr));
if (icmp6 == NULL) {
icmp6stat_inc(icp6s_tooshort);
return (-1);
}
eip6 = (struct ip6_hdr *)(icmp6 + 1);
bzero(&icmp6dst, sizeof(icmp6dst));
icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
icmp6dst.sin6_family = AF_INET6;
if (finaldst == NULL)
icmp6dst.sin6_addr = eip6->ip6_dst;
else
icmp6dst.sin6_addr = *finaldst;
icmp6dst.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.ph_ifidx,
&icmp6dst.sin6_addr);
if (in6_embedscope(&icmp6dst.sin6_addr, &icmp6dst,
NULL, NULL)) {
/* should be impossible */
nd6log((LOG_DEBUG,
"icmp6_notify_error: in6_embedscope failed\n"));
goto freeit;
}
/*
* retrieve parameters from the inner IPv6 header, and convert
* them into sockaddr structures.
*/
bzero(&icmp6src, sizeof(icmp6src));
icmp6src.sin6_len = sizeof(struct sockaddr_in6);
icmp6src.sin6_family = AF_INET6;
icmp6src.sin6_addr = eip6->ip6_src;
icmp6src.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.ph_ifidx,
&icmp6src.sin6_addr);
if (in6_embedscope(&icmp6src.sin6_addr, &icmp6src,
NULL, NULL)) {
/* should be impossible */
nd6log((LOG_DEBUG,
"icmp6_notify_error: in6_embedscope failed\n"));
goto freeit;
}
icmp6src.sin6_flowinfo =
(eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
if (finaldst == NULL)
finaldst = &eip6->ip6_dst;
ip6cp.ip6c_m = m;
ip6cp.ip6c_icmp6 = icmp6;
ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
ip6cp.ip6c_off = eoff;
ip6cp.ip6c_finaldst = finaldst;
ip6cp.ip6c_src = &icmp6src;
ip6cp.ip6c_nxt = nxt;
#if NPF > 0
pf_pkt_addr_changed(m);
#endif
if (icmp6type == ICMP6_PACKET_TOO_BIG) {
notifymtu = ntohl(icmp6->icmp6_mtu);
ip6cp.ip6c_cmdarg = (void *)&notifymtu;
}
ctlfunc = inet6sw[ip6_protox[nxt]].pr_ctlinput;
if (ctlfunc)
(*ctlfunc)(code, sin6tosa(&icmp6dst),
m->m_pkthdr.ph_rtableid, &ip6cp);
}
return (0);
freeit:
m_freem(m);
return (-1);
}
void
icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
{
unsigned long rtcount;
struct icmp6_mtudisc_callback *mc;
struct in6_addr *dst = ip6cp->ip6c_finaldst;
struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
u_int mtu = ntohl(icmp6->icmp6_mtu);
struct rtentry *rt = NULL;
struct sockaddr_in6 sin6;
if (mtu < IPV6_MMTU)
return;
/*
* allow non-validated cases if memory is plenty, to make traffic
* from non-connected pcb happy.
*/
rtcount = rt_timer_queue_count(&icmp6_mtudisc_timeout_q);
if (validated) {
if (0 <= icmp6_mtudisc_hiwat && rtcount > icmp6_mtudisc_hiwat)
return;
else if (0 <= icmp6_mtudisc_lowat &&
rtcount > icmp6_mtudisc_lowat) {
/*
* XXX nuke a victim, install the new one.
*/
}
} else {
if (0 <= icmp6_mtudisc_lowat && rtcount > icmp6_mtudisc_lowat)
return;
}
bzero(&sin6, sizeof(sin6));
sin6.sin6_family = PF_INET6;
sin6.sin6_len = sizeof(struct sockaddr_in6);
sin6.sin6_addr = *dst;
/* XXX normally, this won't happen */
if (IN6_IS_ADDR_LINKLOCAL(dst)) {
sin6.sin6_addr.s6_addr16[1] = htons(m->m_pkthdr.ph_ifidx);
}
sin6.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.ph_ifidx,
&sin6.sin6_addr);
rt = icmp6_mtudisc_clone(&sin6, m->m_pkthdr.ph_rtableid, 0);
if (rt != NULL && ISSET(rt->rt_flags, RTF_HOST) &&
!(rt->rt_locks & RTV_MTU) &&
(rt->rt_mtu > mtu || rt->rt_mtu == 0)) {
struct ifnet *ifp;
ifp = if_get(rt->rt_ifidx);
if (ifp != NULL && mtu < ifp->if_mtu) {
icmp6stat_inc(icp6s_pmtuchg);
rt->rt_mtu = mtu;
}
if_put(ifp);
}
rtfree(rt);
/*
* Notify protocols that the MTU for this destination
* has changed.
*/
LIST_FOREACH(mc, &icmp6_mtudisc_callbacks, mc_list)
(*mc->mc_func)(&sin6, m->m_pkthdr.ph_rtableid);
}
/*
* Reflect the ip6 packet back to the source.
* OFF points to the icmp6 header, counted from the top of the mbuf.
*/
int
icmp6_reflect(struct mbuf **mp, size_t off, struct sockaddr *sa)
{
struct mbuf *m = *mp;
struct rtentry *rt = NULL;
struct ip6_hdr *ip6;
struct icmp6_hdr *icmp6;
struct in6_addr t, *src = NULL;
struct sockaddr_in6 sa6_src, sa6_dst;
u_int rtableid;
u_int8_t pfflags;
CTASSERT(sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) <= MHLEN);
/* too short to reflect */
if (off < sizeof(struct ip6_hdr)) {
nd6log((LOG_DEBUG,
"sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
(u_long)off, (u_long)sizeof(struct ip6_hdr),
__FILE__, __LINE__));
goto bad;
}
if (m->m_pkthdr.ph_loopcnt++ >= M_MAXLOOP) {
m_freemp(mp);
return (ELOOP);
}
rtableid = m->m_pkthdr.ph_rtableid;
pfflags = m->m_pkthdr.pf.flags;
m_resethdr(m);
m->m_pkthdr.ph_rtableid = rtableid;
m->m_pkthdr.pf.flags = pfflags & PF_TAG_GENERATED;
/*
* If there are extra headers between IPv6 and ICMPv6, strip
* off that header first.
*/
if (off > sizeof(struct ip6_hdr)) {
size_t l;
struct ip6_hdr nip6;
l = off - sizeof(struct ip6_hdr);
m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
m_adj(m, l);
l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
if (m->m_len < l) {
if ((m = *mp = m_pullup(m, l)) == NULL)
return (EMSGSIZE);
}
memcpy(mtod(m, caddr_t), &nip6, sizeof(nip6));
} else /* off == sizeof(struct ip6_hdr) */ {
size_t l;
l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
if (m->m_len < l) {
if ((m = *mp = m_pullup(m, l)) == NULL)
return (EMSGSIZE);
}
}
ip6 = mtod(m, struct ip6_hdr *);
ip6->ip6_nxt = IPPROTO_ICMPV6;
icmp6 = (struct icmp6_hdr *)(ip6 + 1);
t = ip6->ip6_dst;
/*
* ip6_input() drops a packet if its src is multicast.
* So, the src is never multicast.
*/
ip6->ip6_dst = ip6->ip6_src;
/*
* XXX: make sure to embed scope zone information, using
* already embedded IDs or the received interface (if any).
* Note that rcvif may be NULL.
* TODO: scoped routing case (XXX).
*/
bzero(&sa6_src, sizeof(sa6_src));
sa6_src.sin6_family = AF_INET6;
sa6_src.sin6_len = sizeof(sa6_src);
sa6_src.sin6_addr = ip6->ip6_dst;
bzero(&sa6_dst, sizeof(sa6_dst));
sa6_dst.sin6_family = AF_INET6;
sa6_dst.sin6_len = sizeof(sa6_dst);
sa6_dst.sin6_addr = t;
if (sa == NULL) {
/*
* If the incoming packet was addressed directly to us (i.e.
* unicast), use dst as the src for the reply. The
* IN6_IFF_TENTATIVE|IN6_IFF_DUPLICATED case would be VERY rare,
* but is possible (for example) when we encounter an error
* while forwarding procedure destined to a duplicated address
* of ours.
*/
rt = rtalloc(sin6tosa(&sa6_dst), 0, rtableid);
if (rtisvalid(rt) && ISSET(rt->rt_flags, RTF_LOCAL) &&
!ISSET(ifatoia6(rt->rt_ifa)->ia6_flags,
IN6_IFF_ANYCAST|IN6_IFF_TENTATIVE|IN6_IFF_DUPLICATED)) {
src = &t;
}
rtfree(rt);
rt = NULL;
sa = sin6tosa(&sa6_src);
}
if (src == NULL) {
struct in6_ifaddr *ia6;
/*
* This case matches to multicasts, our anycast, or unicasts
* that we do not own. Select a source address based on the
* source address of the erroneous packet.
*/
rt = rtalloc(sa, RT_RESOLVE, 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, &sa6_src.sin6_addr,
addr, sizeof(addr))));
rtfree(rt);
goto bad;
}
ia6 = in6_ifawithscope(rt->rt_ifa->ifa_ifp, &t, rtableid);
if (ia6 != NULL)
src = &ia6->ia_addr.sin6_addr;
if (src == NULL)
src = &ifatoia6(rt->rt_ifa)->ia_addr.sin6_addr;
}
ip6->ip6_src = *src;
rtfree(rt);
ip6->ip6_flow = 0;
ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
ip6->ip6_vfc |= IPV6_VERSION;
ip6->ip6_nxt = IPPROTO_ICMPV6;
ip6->ip6_hlim = ip6_defhlim;
icmp6->icmp6_cksum = 0;
m->m_pkthdr.csum_flags = M_ICMP_CSUM_OUT;
/*
* XXX option handling
*/
m->m_flags &= ~(M_BCAST|M_MCAST);
return (0);
bad:
m_freemp(mp);
return (EHOSTUNREACH);
}
void
icmp6_fasttimo(void)
{
mld6_fasttimeo();
}
const char *
icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
struct in6_addr *tgt6)
{
static char buf[1024]; /* XXX */
char src[INET6_ADDRSTRLEN];
char dst[INET6_ADDRSTRLEN];
char tgt[INET6_ADDRSTRLEN];
snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
inet_ntop(AF_INET6, src6, src, sizeof(src)),
inet_ntop(AF_INET6, dst6, dst, sizeof(dst)),
inet_ntop(AF_INET6, tgt6, tgt, sizeof(tgt)));
return buf;
}
void
icmp6_redirect_input(struct mbuf *m, int off)
{
struct ifnet *ifp;
struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
struct nd_redirect *nd_rd;
int icmp6len = ntohs(ip6->ip6_plen);
char *lladdr = NULL;
int lladdrlen = 0;
struct rtentry *rt = NULL;
int is_router;
int is_onlink;
struct in6_addr src6 = ip6->ip6_src;
struct in6_addr redtgt6;
struct in6_addr reddst6;
struct nd_opts ndopts;
char addr[INET6_ADDRSTRLEN];
ifp = if_get(m->m_pkthdr.ph_ifidx);
if (ifp == NULL)
return;
/* XXX if we are router, we don't update route by icmp6 redirect */
if (ip6_forwarding)
goto freeit;
if (!(ifp->if_xflags & IFXF_AUTOCONF6))
goto freeit;
IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
if (nd_rd == NULL) {
icmp6stat_inc(icp6s_tooshort);
if_put(ifp);
return;
}
redtgt6 = nd_rd->nd_rd_target;
reddst6 = nd_rd->nd_rd_dst;
if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
redtgt6.s6_addr16[1] = htons(ifp->if_index);
if (IN6_IS_ADDR_LINKLOCAL(&reddst6))
reddst6.s6_addr16[1] = htons(ifp->if_index);
/* validation */
if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
nd6log((LOG_ERR,
"ICMP6 redirect sent from %s rejected; "
"must be from linklocal\n",
inet_ntop(AF_INET6, &src6, addr, sizeof(addr))));
goto bad;
}
if (ip6->ip6_hlim != 255) {
nd6log((LOG_ERR,
"ICMP6 redirect sent from %s rejected; "
"hlim=%d (must be 255)\n",
inet_ntop(AF_INET6, &src6, addr, sizeof(addr)),
ip6->ip6_hlim));
goto bad;
}
if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
nd6log((LOG_ERR,
"ICMP6 redirect rejected; "
"redirect dst must be unicast: %s\n",
icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
goto bad;
}
{
/* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
struct sockaddr_in6 sin6;
struct in6_addr *gw6;
bzero(&sin6, sizeof(sin6));
sin6.sin6_family = AF_INET6;
sin6.sin6_len = sizeof(struct sockaddr_in6);
memcpy(&sin6.sin6_addr, &reddst6, sizeof(reddst6));
rt = rtalloc(sin6tosa(&sin6), 0, m->m_pkthdr.ph_rtableid);
if (rt) {
if (rt->rt_gateway == NULL ||
rt->rt_gateway->sa_family != AF_INET6) {
nd6log((LOG_ERR,
"ICMP6 redirect rejected; no route "
"with inet6 gateway found for redirect dst: %s\n",
icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
rtfree(rt);
goto bad;
}
gw6 = &(satosin6(rt->rt_gateway)->sin6_addr);
if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
nd6log((LOG_ERR,
"ICMP6 redirect rejected; "
"not equal to gw-for-src=%s (must be same): "
"%s\n",
inet_ntop(AF_INET6, gw6, addr, sizeof(addr)),
icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
rtfree(rt);
goto bad;
}
} else {
nd6log((LOG_ERR,
"ICMP6 redirect rejected; "
"no route found for redirect dst: %s\n",
icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
goto bad;
}
rtfree(rt);
rt = NULL;
}
is_router = is_onlink = 0;
if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
is_router = 1; /* router case */
if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
is_onlink = 1; /* on-link destination case */
if (!is_router && !is_onlink) {
nd6log((LOG_ERR,
"ICMP6 redirect rejected; "
"neither router case nor onlink case: %s\n",
icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
goto bad;
}
/* validation passed */
icmp6len -= sizeof(*nd_rd);
if (nd6_options(nd_rd + 1, icmp6len, &ndopts) < 0) {
nd6log((LOG_INFO, "icmp6_redirect_input: "
"invalid ND option, rejected: %s\n",
icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
/* 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;
}
if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
nd6log((LOG_INFO,
"icmp6_redirect_input: lladdrlen mismatch for %s "
"(if %d, icmp6 packet %d): %s\n",
inet_ntop(AF_INET6, &redtgt6, addr, sizeof(addr)),
ifp->if_addrlen, lladdrlen - 2,
icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
goto bad;
}
/* RFC 2461 8.3 */
nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
if (!is_onlink) { /* better router case. perform rtredirect. */
/* perform rtredirect */
struct sockaddr_in6 sdst;
struct sockaddr_in6 sgw;
struct sockaddr_in6 ssrc;
unsigned long rtcount;
struct rtentry *newrt = NULL;
/*
* do not install redirect route, if the number of entries
* is too much (> hiwat). note that, the node (= host) will
* work just fine even if we do not install redirect route
* (there will be additional hops, though).
*/
rtcount = rt_timer_queue_count(&icmp6_redirect_timeout_q);
if (0 <= ip6_maxdynroutes && rtcount >= ip6_maxdynroutes)
goto freeit;
bzero(&sdst, sizeof(sdst));
bzero(&sgw, sizeof(sgw));
bzero(&ssrc, sizeof(ssrc));
sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
sizeof(struct sockaddr_in6);
memcpy(&sgw.sin6_addr, &redtgt6, sizeof(struct in6_addr));
memcpy(&sdst.sin6_addr, &reddst6, sizeof(struct in6_addr));
memcpy(&ssrc.sin6_addr, &src6, sizeof(struct in6_addr));
rtredirect(sin6tosa(&sdst), sin6tosa(&sgw), sin6tosa(&ssrc),
&newrt, m->m_pkthdr.ph_rtableid);
if (newrt != NULL && icmp6_redirtimeout > 0) {
rt_timer_add(newrt, &icmp6_redirect_timeout_q,
m->m_pkthdr.ph_rtableid);
}
rtfree(newrt);
}
/* finally update cached route in each socket via pfctlinput */
{
struct sockaddr_in6 sdst;
bzero(&sdst, sizeof(sdst));
sdst.sin6_family = AF_INET6;
sdst.sin6_len = sizeof(struct sockaddr_in6);
memcpy(&sdst.sin6_addr, &reddst6, sizeof(struct in6_addr));
pfctlinput(PRC_REDIRECT_HOST, sin6tosa(&sdst));
}
freeit:
if_put(ifp);
m_freem(m);
return;
bad:
if_put(ifp);
icmp6stat_inc(icp6s_badredirect);
m_freem(m);
}
void
icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
{
struct ifnet *ifp = NULL;
struct in6_addr *ifp_ll6;
struct in6_addr *nexthop;
struct ip6_hdr *sip6; /* m0 as struct ip6_hdr */
struct mbuf *m = NULL; /* newly allocated one */
struct ip6_hdr *ip6; /* m as struct ip6_hdr */
struct nd_redirect *nd_rd;
size_t maxlen;
u_char *p;
struct sockaddr_in6 src_sa;
icmp6_errcount(ND_REDIRECT, 0);
/* if we are not router, we don't send icmp6 redirect */
if (!ip6_forwarding)
goto fail;
/* sanity check */
if (m0 == NULL || !rtisvalid(rt))
goto fail;
ifp = if_get(rt->rt_ifidx);
if (ifp == NULL)
goto fail;
/*
* Address check:
* the source address must identify a neighbor, and
* the destination address must not be a multicast address
* [RFC 2461, sec 8.2]
*/
sip6 = mtod(m0, struct ip6_hdr *);
bzero(&src_sa, sizeof(src_sa));
src_sa.sin6_family = AF_INET6;
src_sa.sin6_len = sizeof(src_sa);
src_sa.sin6_addr = sip6->ip6_src;
/* we don't currently use sin6_scope_id, but eventually use it */
src_sa.sin6_scope_id = in6_addr2scopeid(ifp->if_index, &sip6->ip6_src);
if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
goto fail;
if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
goto fail; /* what should we do here? */
/* rate limit */
if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
goto fail;
/*
* Since we are going to append up to 1280 bytes (= IPV6_MMTU),
* we almost always ask for an mbuf cluster for simplicity.
* (MHLEN < IPV6_MMTU is almost always true)
*/
#if IPV6_MMTU >= MCLBYTES
# error assumption failed about IPV6_MMTU and MCLBYTES
#endif
MGETHDR(m, M_DONTWAIT, MT_HEADER);
if (m && IPV6_MMTU >= MHLEN)
MCLGET(m, M_DONTWAIT);
if (!m)
goto fail;
m->m_pkthdr.ph_ifidx = 0;
m->m_len = 0;
maxlen = m_trailingspace(m);
maxlen = min(IPV6_MMTU, maxlen);
/* just for safety */
if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
goto fail;
}
{
/* get ip6 linklocal address for ifp(my outgoing interface). */
struct in6_ifaddr *ia6;
if ((ia6 = in6ifa_ifpforlinklocal(ifp, IN6_IFF_TENTATIVE|
IN6_IFF_DUPLICATED|IN6_IFF_ANYCAST)) == NULL)
goto fail;
ifp_ll6 = &ia6->ia_addr.sin6_addr;
}
/* get ip6 linklocal address for the router. */
if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
struct sockaddr_in6 *sin6;
sin6 = satosin6(rt->rt_gateway);
nexthop = &sin6->sin6_addr;
if (!IN6_IS_ADDR_LINKLOCAL(nexthop))
nexthop = NULL;
} else
nexthop = NULL;
/* ip6 */
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;
/* ip6->ip6_src must be linklocal addr for my outgoing if. */
bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
/* ND Redirect */
nd_rd = (struct nd_redirect *)(ip6 + 1);
nd_rd->nd_rd_type = ND_REDIRECT;
nd_rd->nd_rd_code = 0;
nd_rd->nd_rd_reserved = 0;
if (rt->rt_flags & RTF_GATEWAY) {
/*
* nd_rd->nd_rd_target must be a link-local address in
* better router cases.
*/
if (!nexthop)
goto fail;
bcopy(nexthop, &nd_rd->nd_rd_target,
sizeof(nd_rd->nd_rd_target));
bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
sizeof(nd_rd->nd_rd_dst));
} else {
/* make sure redtgt == reddst */
nexthop = &sip6->ip6_dst;
bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
sizeof(nd_rd->nd_rd_target));
bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
sizeof(nd_rd->nd_rd_dst));
}
p = (u_char *)(nd_rd + 1);
{
/* target lladdr option */
struct rtentry *nrt;
int len;
struct sockaddr_dl *sdl;
struct nd_opt_hdr *nd_opt;
char *lladdr;
len = sizeof(*nd_opt) + ifp->if_addrlen;
len = (len + 7) & ~7; /* round by 8 */
/* safety check */
if (len + (p - (u_char *)ip6) > maxlen)
goto nolladdropt;
nrt = nd6_lookup(nexthop, 0, ifp, ifp->if_rdomain);
if ((nrt != NULL) &&
(nrt->rt_flags & (RTF_GATEWAY|RTF_LLINFO)) == RTF_LLINFO &&
(nrt->rt_gateway->sa_family == AF_LINK) &&
(sdl = satosdl(nrt->rt_gateway)) &&
sdl->sdl_alen) {
nd_opt = (struct nd_opt_hdr *)p;
nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
nd_opt->nd_opt_len = len >> 3;
lladdr = (char *)(nd_opt + 1);
bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen);
p += len;
}
rtfree(nrt);
}
nolladdropt:;
m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
/* just to be safe */
if (p - (u_char *)ip6 > maxlen)
goto noredhdropt;
{
/* redirected header option */
int len;
struct nd_opt_rd_hdr *nd_opt_rh;
/*
* compute the maximum size for icmp6 redirect header option.
* XXX room for auth header?
*/
len = maxlen - (p - (u_char *)ip6);
len &= ~7;
/*
* Redirected header option spec (RFC2461 4.6.3) talks nothing
* about padding/truncate rule for the original IP packet.
* From the discussion on IPv6imp in Feb 1999,
* the consensus was:
* - "attach as much as possible" is the goal
* - pad if not aligned (original size can be guessed by
* original ip6 header)
* Following code adds the padding if it is simple enough,
* and truncates if not.
*/
if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
/* not enough room, truncate */
m_adj(m0, (len - sizeof(*nd_opt_rh)) -
m0->m_pkthdr.len);
} else {
/*
* enough room, truncate if not aligned.
* we don't pad here for simplicity.
*/
size_t extra;
extra = m0->m_pkthdr.len % 8;
if (extra) {
/* truncate */
m_adj(m0, -extra);
}
len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
}
nd_opt_rh = (struct nd_opt_rd_hdr *)p;
bzero(nd_opt_rh, sizeof(*nd_opt_rh));
nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
nd_opt_rh->nd_opt_rh_len = len >> 3;
p += sizeof(*nd_opt_rh);
m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
/* connect m0 to m */
m->m_pkthdr.len += m0->m_pkthdr.len;
m_cat(m, m0);
m0 = NULL;
}
noredhdropt:
m_freem(m0);
m0 = NULL;
sip6 = mtod(m, struct ip6_hdr *);
if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_src))
sip6->ip6_src.s6_addr16[1] = 0;
if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_dst))
sip6->ip6_dst.s6_addr16[1] = 0;
#if 0
if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
ip6->ip6_src.s6_addr16[1] = 0;
if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
ip6->ip6_dst.s6_addr16[1] = 0;
#endif
if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_target))
nd_rd->nd_rd_target.s6_addr16[1] = 0;
if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_dst))
nd_rd->nd_rd_dst.s6_addr16[1] = 0;
ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
nd_rd->nd_rd_cksum = 0;
m->m_pkthdr.csum_flags = M_ICMP_CSUM_OUT;
/* send the packet to outside... */
ip6_output(m, NULL, NULL, 0, NULL, NULL);
icmp6stat_inc(icp6s_outhist + ND_REDIRECT);
if_put(ifp);
return;
fail:
if_put(ifp);
m_freem(m);
m_freem(m0);
}
/*
* ICMPv6 socket option processing.
*/
int
icmp6_ctloutput(int op, struct socket *so, int level, int optname,
struct mbuf *m)
{
int error = 0;
struct inpcb *inp = sotoinpcb(so);
if (level != IPPROTO_ICMPV6)
return EINVAL;
switch (op) {
case PRCO_SETOPT:
switch (optname) {
case ICMP6_FILTER:
{
struct icmp6_filter *p;
if (m == NULL || m->m_len != sizeof(*p)) {
error = EMSGSIZE;
break;
}
p = mtod(m, struct icmp6_filter *);
if (!p || !inp->inp_icmp6filt) {
error = EINVAL;
break;
}
bcopy(p, inp->inp_icmp6filt,
sizeof(struct icmp6_filter));
error = 0;
break;
}
default:
error = ENOPROTOOPT;
break;
}
break;
case PRCO_GETOPT:
switch (optname) {
case ICMP6_FILTER:
{
struct icmp6_filter *p;
if (!inp->inp_icmp6filt) {
error = EINVAL;
break;
}
m->m_len = sizeof(struct icmp6_filter);
p = mtod(m, struct icmp6_filter *);
bcopy(inp->inp_icmp6filt, p,
sizeof(struct icmp6_filter));
error = 0;
break;
}
default:
error = ENOPROTOOPT;
break;
}
break;
}
return (error);
}
/*
* Perform rate limit check.
* Returns 0 if it is okay to send the icmp6 packet.
* Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
* limitation.
*
* XXX per-destination/type check necessary?
*
* dst - not used at this moment
* type - not used at this moment
* code - not used at this moment
*/
int
icmp6_ratelimit(const struct in6_addr *dst, const int type, const int code)
{
/* PPS limit */
if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count,
icmp6errppslim))
return 1; /* The packet is subject to rate limit */
return 0; /* okay to send */
}
struct rtentry *
icmp6_mtudisc_clone(struct sockaddr_in6 *dst, u_int rtableid, int ipsec)
{
struct rtentry *rt;
int error;
rt = rtalloc(sin6tosa(dst), RT_RESOLVE, rtableid);
/* Check if the route is actually usable */
if (!rtisvalid(rt))
goto bad;
/* IPsec needs the route only for PMTU, it can use reject for that */
if (!ipsec && (rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)))
goto bad;
/*
* No PMTU for local routes and permanent neighbors,
* ARP and NDP use the same expire timer as the route.
*/
if (ISSET(rt->rt_flags, RTF_LOCAL) ||
(ISSET(rt->rt_flags, RTF_LLINFO) && rt->rt_expire == 0))
goto bad;
/* If we didn't get a host route, allocate one */
if ((rt->rt_flags & RTF_HOST) == 0) {
struct rtentry *nrt;
struct rt_addrinfo info;
struct sockaddr_rtlabel sa_rl;
memset(&info, 0, sizeof(info));
info.rti_ifa = rt->rt_ifa;
info.rti_flags = RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC;
info.rti_info[RTAX_DST] = sin6tosa(dst);
info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
info.rti_info[RTAX_LABEL] =
rtlabel_id2sa(rt->rt_labelid, &sa_rl);
error = rtrequest(RTM_ADD, &info, rt->rt_priority, &nrt,
rtableid);
if (error)
goto bad;
nrt->rt_rmx = rt->rt_rmx;
rtfree(rt);
rt = nrt;
rtm_send(rt, RTM_ADD, 0, rtableid);
}
error = rt_timer_add(rt, &icmp6_mtudisc_timeout_q, rtableid);
if (error)
goto bad;
return (rt);
bad:
rtfree(rt);
return (NULL);
}
void
icmp6_mtudisc_timeout(struct rtentry *rt, u_int rtableid)
{
struct ifnet *ifp;
NET_ASSERT_LOCKED();
ifp = if_get(rt->rt_ifidx);
if (ifp == NULL)
return;
if ((rt->rt_flags & (RTF_DYNAMIC|RTF_HOST)) == (RTF_DYNAMIC|RTF_HOST)) {
rtdeletemsg(rt, ifp, rtableid);
} else {
if (!(rt->rt_locks & RTV_MTU))
rt->rt_mtu = 0;
}
if_put(ifp);
}
const struct sysctl_bounded_args icmpv6ctl_vars[] = {
{ ICMPV6CTL_ND6_DELAY, &nd6_delay, 0, INT_MAX },
{ ICMPV6CTL_ND6_UMAXTRIES, &nd6_umaxtries, 0, INT_MAX },
{ ICMPV6CTL_ND6_MMAXTRIES, &nd6_mmaxtries, 0, INT_MAX },
{ ICMPV6CTL_ERRPPSLIMIT, &icmp6errppslim, -1, 1000 },
{ ICMPV6CTL_ND6_MAXNUDHINT, &nd6_maxnudhint, 0, INT_MAX },
{ ICMPV6CTL_MTUDISC_HIWAT, &icmp6_mtudisc_hiwat, -1, INT_MAX },
{ ICMPV6CTL_MTUDISC_LOWAT, &icmp6_mtudisc_lowat, -1, INT_MAX },
{ ICMPV6CTL_ND6_DEBUG, &nd6_debug, 0, 1 },
};
int
icmp6_sysctl_icmp6stat(void *oldp, size_t *oldlenp, void *newp)
{
struct icmp6stat *icmp6stat;
int ret;
CTASSERT(sizeof(*icmp6stat) == icp6s_ncounters * sizeof(uint64_t));
icmp6stat = malloc(sizeof(*icmp6stat), M_TEMP, M_WAITOK|M_ZERO);
counters_read(icmp6counters, (uint64_t *)icmp6stat, icp6s_ncounters,
NULL);
ret = sysctl_rdstruct(oldp, oldlenp, newp,
icmp6stat, sizeof(*icmp6stat));
free(icmp6stat, M_TEMP, sizeof(*icmp6stat));
return (ret);
}
int
icmp6_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
void *newp, size_t newlen)
{
int error;
/* All sysctl names at this level are terminal. */
if (namelen != 1)
return (ENOTDIR);
switch (name[0]) {
case ICMPV6CTL_REDIRTIMEOUT:
NET_LOCK();
error = sysctl_int_bounded(oldp, oldlenp, newp, newlen,
&icmp6_redirtimeout, 0, INT_MAX);
rt_timer_queue_change(&icmp6_redirect_timeout_q,
icmp6_redirtimeout);
NET_UNLOCK();
break;
case ICMPV6CTL_STATS:
error = icmp6_sysctl_icmp6stat(oldp, oldlenp, newp);
break;
case ICMPV6CTL_ND6_QUEUED:
error = sysctl_rdint(oldp, oldlenp, newp,
atomic_load_int(&ln_hold_total));
break;
default:
NET_LOCK();
error = sysctl_bounded_arr(icmpv6ctl_vars,
nitems(icmpv6ctl_vars), name, namelen, oldp, oldlenp, newp,
newlen);
NET_UNLOCK();
break;
}
return (error);
}
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