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darling-xnu/bsd/netinet6/icmp6.c
Thomas A cdbc10b677 Upload xnu-7195.141.2 Source
2023-05-16 21:41:14 -07:00

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/*
* Copyright (c) 2000-2020 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/* $FreeBSD: src/sys/netinet6/icmp6.c,v 1.6.2.6 2001/07/10 09:44:16 ume Exp $ */
/* $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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 <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mcache.h>
#include <sys/mbuf.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 <sys/domain.h>
#include <sys/kauth.h>
#include <net/if.h>
#include <net/route.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <netinet/in.h>
#include <netinet/in_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/in6_pcb.h>
#include <netinet6/in6_var.h>
#include <netinet6/nd6.h>
#include <netinet6/in6_ifattach.h>
#include <netinet6/ip6protosw.h>
#include <netinet6/scope6_var.h>
#if IPSEC
#include <netinet6/ipsec.h>
#include <netkey/key.h>
#endif
#include <net/net_osdep.h>
#if NECP
#include <net/necp.h>
#endif
extern struct ip6protosw *ip6_protox[];
extern uint32_t rip_sendspace;
extern uint32_t rip_recvspace;
struct icmp6stat icmp6stat;
extern struct inpcbhead ripcb;
extern int icmp6errppslim;
extern int icmp6errppslim_random_incr;
extern int icmp6rappslim;
static int icmp6errpps_count = 0;
static int icmp6rapps_count = 0;
static struct timeval icmp6errppslim_last;
static struct timeval icmp6rappslim_last;
extern int icmp6_nodeinfo;
extern struct inpcbinfo ripcbinfo;
static void icmp6_errcount(struct icmp6errstat *, int, int);
static int icmp6_rip6_input(struct mbuf **, int);
static int icmp6_ratelimit(const struct in6_addr *, const int, const int);
static const char *icmp6_redirect_diag(struct in6_addr *,
struct in6_addr *, struct in6_addr *);
static struct mbuf *ni6_input(struct mbuf *, int);
static struct mbuf *ni6_nametodns(const char *, uint32_t, int);
static int ni6_dnsmatch(const char *, int, const char *, int);
static int ni6_addrs(struct icmp6_nodeinfo *,
struct ifnet **, char *);
static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
struct ifnet *, int);
static int icmp6_notify_error(struct mbuf *, int, int, int);
void
icmp6_init(struct ip6protosw *pp, struct domain *dp)
{
#pragma unused(dp)
static int icmp6_initialized = 0;
/* Also called from ip6_init() without pp */
VERIFY(pp == NULL ||
(pp->pr_flags & (PR_INITIALIZED | PR_ATTACHED)) == PR_ATTACHED);
/* This gets called by more than one protocols, so initialize once */
if (!icmp6_initialized) {
icmp6_initialized = 1;
mld_init();
if (icmp6errppslim >= 0 &&
icmp6errppslim_random_incr > 0 &&
icmp6errppslim <= INT32_MAX - (icmp6errppslim_random_incr + 1)) {
icmp6errppslim += (random() % icmp6errppslim_random_incr) + 1;
}
}
}
static void
icmp6_errcount(struct icmp6errstat *stat, int type, int code)
{
switch (type) {
case ICMP6_DST_UNREACH:
switch (code) {
case ICMP6_DST_UNREACH_NOROUTE:
stat->icp6errs_dst_unreach_noroute++;
return;
case ICMP6_DST_UNREACH_ADMIN:
stat->icp6errs_dst_unreach_admin++;
return;
case ICMP6_DST_UNREACH_BEYONDSCOPE:
stat->icp6errs_dst_unreach_beyondscope++;
return;
case ICMP6_DST_UNREACH_ADDR:
stat->icp6errs_dst_unreach_addr++;
return;
case ICMP6_DST_UNREACH_NOPORT:
stat->icp6errs_dst_unreach_noport++;
return;
}
break;
case ICMP6_PACKET_TOO_BIG:
stat->icp6errs_packet_too_big++;
return;
case ICMP6_TIME_EXCEEDED:
switch (code) {
case ICMP6_TIME_EXCEED_TRANSIT:
stat->icp6errs_time_exceed_transit++;
return;
case ICMP6_TIME_EXCEED_REASSEMBLY:
stat->icp6errs_time_exceed_reassembly++;
return;
}
break;
case ICMP6_PARAM_PROB:
switch (code) {
case ICMP6_PARAMPROB_HEADER:
stat->icp6errs_paramprob_header++;
return;
case ICMP6_PARAMPROB_NEXTHEADER:
stat->icp6errs_paramprob_nextheader++;
return;
case ICMP6_PARAMPROB_OPTION:
stat->icp6errs_paramprob_option++;
return;
}
break;
case ND_REDIRECT:
stat->icp6errs_redirect++;
return;
}
stat->icp6errs_unknown++;
}
/*
* A wrapper function for icmp6_error() necessary when the erroneous packet
* may not contain enough scope zone information.
*/
void
icmp6_error2(struct mbuf *m, int type, int code, int param,
struct ifnet *ifp)
{
struct ip6_hdr *ip6;
if (ifp == NULL) {
return;
}
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), return );
#else
if (m->m_len < sizeof(struct ip6_hdr)) {
m = m_pullup(m, sizeof(struct ip6_hdr));
if (m == NULL) {
return;
}
}
#endif
ip6 = mtod(m, struct ip6_hdr *);
if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0) {
return;
}
if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0) {
return;
}
icmp6_error(m, type, code, param);
}
/*
* 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)
{
icmp6_error_flag(m, type, code, param, ICMP6_ERROR_RST_MRCVIF);
}
void
icmp6_error_flag(struct mbuf *m, int type, int code, int param, int flags)
{
struct ip6_hdr *oip6, *nip6;
struct icmp6_hdr *icmp6;
u_int preplen;
int off;
icmp6stat.icp6s_error++;
/* count per-type-code statistics */
icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code);
#ifdef M_DECRYPTED /*not openbsd*/
if (m->m_flags & M_DECRYPTED) {
icmp6stat.icp6s_canterror++;
goto freeit;
}
#endif
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), return );
#else
if (m->m_len < sizeof(struct ip6_hdr)) {
m = m_pullup(m, sizeof(struct ip6_hdr));
if (m == NULL) {
return;
}
}
#endif
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 Pakcet 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.
*
* We want to check for that for all ICMP error types, other than
* ICMP6_PARAM_PROB when it is being sent in response of first frag
* with incomplete header.
* That also includes the case when the first frag has incomplete ICMPv6
* header. The check below in that case would fail the IP6_EXTHDR_CHECK
* and would otherwise prevent us from sending the error back.
*/
if (type != ICMP6_PARAM_PROB ||
code != ICMP6_PARAMPROB_FIRSTFRAG_INCOMP_HDR) {
int nxt = -1;
off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
if (off >= 0 && nxt == IPPROTO_ICMPV6) {
struct icmp6_hdr *icp;
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), return );
icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
#else
IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
sizeof(*icp));
if (icp == NULL) {
icmp6stat.icp6s_tooshort++;
return;
}
#endif
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.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.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, 1);
if (m && m->m_len < preplen) {
m = m_pullup(m, preplen);
}
if (m == NULL) {
nd6log(debug, "ENOBUFS in icmp6_error %d\n", __LINE__);
return;
}
nip6 = mtod(m, struct ip6_hdr *);
nip6->ip6_src = oip6->ip6_src;
nip6->ip6_dst = oip6->ip6_dst;
in6_clearscope(&oip6->ip6_src);
in6_clearscope(&oip6->ip6_dst);
icmp6 = (struct icmp6_hdr *)(nip6 + 1);
icmp6->icmp6_type = (uint8_t)type;
icmp6->icmp6_code = (uint8_t)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.rcvif for safety, we should have enough scope
* information in ip header (nip6).
*/
if (flags & ICMP6_ERROR_RST_MRCVIF) {
m->m_pkthdr.rcvif = NULL;
}
icmp6stat.icp6s_outhist[type]++;
icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
return;
freeit:
/*
* If we can't tell whether or not we can generate ICMP6, free it.
*/
m_freem(m);
}
/*
* Process a received ICMP6 message.
*/
int
icmp6_input(struct mbuf **mp, int *offp, int proto)
{
#pragma unused(proto)
struct mbuf *m = *mp, *n;
struct ifnet *ifp;
struct ip6_hdr *ip6, *nip6;
struct icmp6_hdr *icmp6, *nicmp6;
int off = *offp;
int icmp6len = m->m_pkthdr.len - *offp;
int code, sum, noff, proxy = 0;
ifp = m->m_pkthdr.rcvif;
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), return IPPROTO_DONE);
/* m might change if M_LOOP. So, call mtod after this */
#endif
/* Expect 32-bit aligned data pointer on strict-align platforms */
MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);
/*
* 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.icp6s_tooshort++;
goto freeit;
}
#ifndef PULLDOWN_TEST
icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
#else
IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
if (icmp6 == NULL) {
icmp6stat.icp6s_tooshort++;
return IPPROTO_DONE;
}
#endif
code = icmp6->icmp6_code;
/*
* Early check for RFC 6980
* Drop certain NDP packets if they came in fragmented
*/
switch (icmp6->icmp6_type) {
case ND_ROUTER_SOLICIT:
case ND_ROUTER_ADVERT:
case ND_NEIGHBOR_SOLICIT:
case ND_NEIGHBOR_ADVERT:
case ND_REDIRECT:
if (m->m_pkthdr.pkt_flags & PKTF_REASSEMBLED) {
icmp6stat.icp6s_rfc6980_drop++;
goto freeit;
}
break;
default:
break;
}
/* Apply rate limit before checksum validation. */
if (icmp6_ratelimit(&ip6->ip6_dst, icmp6->icmp6_type, code)) {
icmp6stat.icp6s_toofreq++;
goto freeit;
}
/*
* Check multicast group membership.
* Note: SSM filters are not applied for ICMPv6 traffic.
*/
if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
struct in6_multi *inm;
in6_multihead_lock_shared();
IN6_LOOKUP_MULTI(&ip6->ip6_dst, ifp, inm);
in6_multihead_lock_done();
if (inm == NULL) {
/*
* Don't discard if this is a Neighbor Solicitation
* that needs to be proxied (see check down below.)
*/
if (!(m->m_pkthdr.pkt_flags & PKTF_PROXY_DST)) {
ip6stat.ip6s_notmember++;
in6_ifstat_inc(m->m_pkthdr.rcvif,
ifs6_in_discard);
goto freeit;
}
} else {
IN6M_REMREF(inm);
}
}
/*
* calculate the checksum
*/
if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
nd6log(error,
"ICMP6 checksum error(%d|%x) %s\n",
icmp6->icmp6_type, sum, ip6_sprintf(&ip6->ip6_src));
icmp6stat.icp6s_checksum++;
goto freeit;
}
if (m->m_pkthdr.pkt_flags & PKTF_PROXY_DST) {
/*
* This is the special case of proxying NS (dst is either
* solicited-node multicast or unicast); process it locally
* but don't deliver it to sockets. It practically lets us
* steer the packet to nd6_prproxy_ns_input, where more
* specific tests and actions will be taken.
*/
switch (icmp6->icmp6_type) {
case ND_NEIGHBOR_SOLICIT:
proxy = 1;
break;
default:
goto freeit;
}
}
icmp6stat.icp6s_inhist[icmp6->icmp6_type]++;
icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg);
if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK) {
icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
}
switch (icmp6->icmp6_type) {
case ICMP6_DST_UNREACH:
icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach);
switch (code) {
case ICMP6_DST_UNREACH_NOROUTE:
case ICMP6_DST_UNREACH_ADDR: /* PRC_HOSTDEAD is a DOS */
code = PRC_UNREACH_NET;
break;
case ICMP6_DST_UNREACH_ADMIN:
icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib);
code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
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:
icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig);
if (ntohl(icmp6->icmp6_mtu) < IPV6_MMTU) {
icmp6stat.icp6s_badpkttoobig++;
goto freeit;
}
code = PRC_MSGSIZE;
/*
* Updating the path MTU will be done after examining
* intermediate extension headers.
*/
goto deliver;
case ICMP6_TIME_EXCEEDED:
icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed);
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:
icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob);
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:
icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo);
if (code != 0) {
goto badcode;
}
if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
/* Give up remote */
goto rate_limit_checked;
}
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);
goto rate_limit_checked;
}
MGETHDR(n, M_DONTWAIT, n0->m_type); /* MAC-OK */
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 remote */
m_freem(n0);
goto rate_limit_checked;
}
M_COPY_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_pkthdr.len = n->m_len =
noff + sizeof(struct icmp6_hdr);
/*
* Adjust mbuf. ip6_plen will be adjusted in
* ip6_output().
*/
m_adj(n0, off + sizeof(struct icmp6_hdr));
n->m_pkthdr.len += n0->m_pkthdr.len;
n->m_next = n0;
n0->m_flags &= ~M_PKTHDR;
} else {
nip6 = mtod(n, struct ip6_hdr *);
IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
sizeof(*nicmp6));
noff = off;
}
if (nicmp6 == NULL) {
panic("nicmp6 is NULL in %s, which isn't good!\n", __FUNCTION__);
} else {
nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
nicmp6->icmp6_code = 0;
}
if (n) {
icmp6stat.icp6s_reflect++;
icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++;
icmp6_reflect(n, noff);
}
goto rate_limit_checked;
case ICMP6_ECHO_REPLY:
icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply);
if (code != 0) {
goto badcode;
}
break;
case MLD_LISTENER_QUERY:
case MLD_LISTENER_REPORT:
if (icmp6len < sizeof(struct mld_hdr)) {
goto badlen;
}
if (icmp6->icmp6_type == MLD_LISTENER_QUERY) { /* XXX: ugly... */
icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery);
} else {
icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport);
}
if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
/* give up local */
if (mld_input(m, off, icmp6len) == IPPROTO_DONE) {
m = NULL;
}
goto freeit;
}
if (mld_input(n, off, icmp6len) != IPPROTO_DONE) {
m_freem(n);
}
/* m stays. */
goto rate_limit_checked;
case MLD_LISTENER_DONE:
icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone);
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_NI_QUERY:
if (!icmp6_nodeinfo) {
break;
}
//### LD 10/20 Check fbsd differences here. Not sure we're more advanced or not.
/* By RFC 4620 refuse to answer queries from global scope addresses */
if ((icmp6_nodeinfo & 8) != 8 && in6_addrscope(&ip6->ip6_src) == IPV6_ADDR_SCOPE_GLOBAL) {
break;
}
if (icmp6len < sizeof(struct icmp6_nodeinfo)) {
goto badlen;
}
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
return IPPROTO_DONE);
#endif
n = m_copy(m, 0, M_COPYALL);
if (n) {
n = ni6_input(n, off);
}
if (n) {
noff = sizeof(struct ip6_hdr);
icmp6stat.icp6s_reflect++;
icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++;
icmp6_reflect(n, noff);
}
goto rate_limit_checked;
case ICMP6_WRUREPLY:
if (code != 0) {
goto badcode;
}
break;
case ND_ROUTER_SOLICIT:
icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit);
if (code != 0) {
goto badcode;
}
if (icmp6len < sizeof(struct nd_router_solicit)) {
goto badlen;
}
if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
/* give up local */
nd6_rs_input(m, off, icmp6len);
m = NULL;
goto freeit;
}
nd6_rs_input(n, off, icmp6len);
/* m stays. */
goto rate_limit_checked;
case ND_ROUTER_ADVERT:
icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert);
if (code != 0) {
goto badcode;
}
if (icmp6len < sizeof(struct nd_router_advert)) {
goto badlen;
}
if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
/* give up local */
nd6_ra_input(m, off, icmp6len);
m = NULL;
goto freeit;
}
nd6_ra_input(n, off, icmp6len);
/* m stays. */
goto rate_limit_checked;
case ND_NEIGHBOR_SOLICIT:
icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit);
if (code != 0) {
goto badcode;
}
if (icmp6len < sizeof(struct nd_neighbor_solicit)) {
goto badlen;
}
if (proxy ||
((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. */
goto rate_limit_checked;
case ND_NEIGHBOR_ADVERT:
icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert);
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. */
goto rate_limit_checked;
case ND_REDIRECT:
icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_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, icmp6len);
m = NULL;
goto freeit;
}
icmp6_redirect_input(n, off, icmp6len);
/* m stays. */
goto rate_limit_checked;
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(debug,
"icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
icmp6->icmp6_type, ip6_sprintf(&ip6->ip6_src),
ip6_sprintf(&ip6->ip6_dst),
m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0);
if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
/* ICMPv6 error: MUST deliver it by spec... */
code = PRC_NCMDS;
/* deliver */
} else {
/* ICMPv6 informational: MUST not deliver */
goto rate_limit_checked;
}
deliver:
if (icmp6_notify_error(m, off, icmp6len, code)) {
/* In this case, m should've been freed. */
return IPPROTO_DONE;
}
break;
badcode:
icmp6stat.icp6s_badcode++;
break;
badlen:
icmp6stat.icp6s_badlen++;
break;
}
rate_limit_checked:
icmp6_rip6_input(&m, *offp);
return IPPROTO_DONE;
freeit:
m_freem(m);
return IPPROTO_DONE;
}
static 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.icp6s_tooshort++;
goto freeit;
}
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off,
sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr),
return -1);
icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
#else
IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
sizeof(*icmp6) + sizeof(struct ip6_hdr));
if (icmp6 == NULL) {
icmp6stat.icp6s_tooshort++;
return -1;
}
#endif
eip6 = (struct ip6_hdr *)(icmp6 + 1);
bzero(&icmp6dst, sizeof(icmp6dst));
/* Detect the upper level protocol */
{
void (*ctlfunc)(int, struct sockaddr *, void *, struct ifnet *);
u_int8_t nxt = eip6->ip6_nxt;
int eoff = off + sizeof(struct icmp6_hdr) +
sizeof(struct ip6_hdr);
struct ip6ctlparam ip6cp;
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:
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, 0,
eoff + sizeof(struct ip6_ext), return -1);
eh = (struct ip6_ext *)(mtod(m, caddr_t)
+ eoff);
#else
IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
eoff, sizeof(*eh));
if (eh == NULL) {
icmp6stat.icp6s_tooshort++;
return -1;
}
#endif
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).
*/
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth),
return -1);
rth = (struct ip6_rthdr *)
(mtod(m, caddr_t) + eoff);
#else
IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
eoff, sizeof(*rth));
if (rth == NULL) {
icmp6stat.icp6s_tooshort++;
return -1;
}
#endif
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;
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, 0, eoff + rthlen,
return -1);
rth0 = (struct ip6_rthdr0 *)(mtod(m, caddr_t) + eoff);
#else
IP6_EXTHDR_GET(rth0,
struct ip6_rthdr0 *, m,
eoff, rthlen);
if (rth0 == NULL) {
icmp6stat.icp6s_tooshort++;
return -1;
}
#endif
/* just ignore a bogus header */
if ((rth0->ip6r0_len % 2) == 0 &&
(hops = rth0->ip6r0_len / 2)) {
icmp6dst.sin6_addr = *((struct in6_addr *)(void *)(rth0 + 1) + (hops - 1));
}
}
eoff += rthlen;
nxt = rth->ip6r_nxt;
break;
case IPPROTO_FRAGMENT:
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, 0, eoff +
sizeof(struct ip6_frag),
return -1);
fh = (struct ip6_frag *)(mtod(m, caddr_t)
+ eoff);
#else
IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
eoff, sizeof(*fh));
if (fh == NULL) {
icmp6stat.icp6s_tooshort++;
return -1;
}
#endif
/*
* 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:
#ifndef PULLDOWN_TEST
icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
#else
IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
sizeof(*icmp6) + sizeof(struct ip6_hdr));
if (icmp6 == NULL) {
icmp6stat.icp6s_tooshort++;
return -1;
}
#endif
/*
* retrieve parameters from the inner IPv6 header, and convert
* them into sockaddr structures.
* XXX: there is no guarantee that the source or destination
* addresses of the inner packet are in the same scope as
* the addresses of the icmp packet. But there is no other
* way to determine the zone.
*/
eip6 = (struct ip6_hdr *)(icmp6 + 1);
icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
icmp6dst.sin6_family = AF_INET6;
if (IN6_IS_ADDR_UNSPECIFIED(&icmp6dst.sin6_addr)) {
icmp6dst.sin6_addr = eip6->ip6_dst;
}
if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL)) {
goto freeit;
}
bzero(&icmp6src, sizeof(icmp6src));
icmp6src.sin6_len = sizeof(struct sockaddr_in6);
icmp6src.sin6_family = AF_INET6;
icmp6src.sin6_addr = eip6->ip6_src;
if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL)) {
goto freeit;
}
icmp6src.sin6_flowinfo =
(eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
ip6cp.ip6c_m = m;
ip6cp.ip6c_icmp6 = icmp6;
ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
ip6cp.ip6c_off = eoff;
ip6cp.ip6c_finaldst = &icmp6dst.sin6_addr;
ip6cp.ip6c_src = &icmp6src;
ip6cp.ip6c_nxt = nxt;
if (icmp6type == ICMP6_PACKET_TOO_BIG) {
notifymtu = ntohl(icmp6->icmp6_mtu);
ip6cp.ip6c_cmdarg = (void *)&notifymtu;
icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/
}
ctlfunc = ip6_protox[nxt]->pr_ctlinput;
if (ctlfunc) {
LCK_MTX_ASSERT(inet6_domain_mutex, LCK_MTX_ASSERT_OWNED);
lck_mtx_unlock(inet6_domain_mutex);
(void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
&ip6cp, m->m_pkthdr.rcvif);
lck_mtx_lock(inet6_domain_mutex);
}
}
return 0;
freeit:
m_freem(m);
return -1;
}
void
icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
{
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;
/*
* we reject ICMPv6 too big with abnormally small value.
* XXX what is the good definition of "abnormally small"?
*/
if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8) {
return;
}
if (!validated) {
return;
}
/* Limit the MTU to the minimum IPv6 MTU */
if (mtu < IPV6_MMTU) {
mtu = IPV6_MMTU;
}
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.rcvif->if_index);
}
/* sin6.sin6_scope_id = XXX: should be set if DST is a scoped addr */
/*
* XXX On a side note, for asymmetric data-path
* the lookup on receive interace is probably not
* what we want to do.
* That requires looking at the cached route for the
* protocol control block.
*/
rt = rtalloc1_scoped((struct sockaddr *)&sin6, 0,
RTF_CLONING | RTF_PRCLONING, m->m_pkthdr.rcvif->if_index);
if (rt != NULL) {
RT_LOCK(rt);
if ((rt->rt_flags & RTF_HOST) &&
!(rt->rt_rmx.rmx_locks & RTV_MTU) &&
mtu < IN6_LINKMTU(rt->rt_ifp) &&
rt->rt_rmx.rmx_mtu > mtu) {
icmp6stat.icp6s_pmtuchg++;
rt->rt_rmx.rmx_mtu = mtu;
}
RT_UNLOCK(rt);
rtfree(rt);
}
}
/*
* Process a Node Information Query packet, based on
* draft-ietf-ipngwg-icmp-name-lookups-07.
*
* Spec incompatibilities:
* - IPv6 Subject address handling
* - IPv4 Subject address handling support missing
* - Proxy reply (answer even if it's not for me)
* - joins NI group address at in6_ifattach() time only, does not cope
* with hostname changes by sethostname(3)
*/
#define hostnamelen (uint32_t)strlen(hostname)
static struct mbuf *
ni6_input(struct mbuf *m, int off)
{
struct icmp6_nodeinfo *ni6, *nni6;
struct mbuf *n = NULL;
u_int16_t qtype;
int subjlen;
int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
struct ni_reply_fqdn *fqdn;
int addrs; /* for NI_QTYPE_NODEADDR */
struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
struct sockaddr_in6 sin6; /* double meaning; ip6_dst and subjectaddr */
struct sockaddr_in6 sin6_d; /* XXX: we should retrieve this from m_aux */
struct ip6_hdr *ip6;
int oldfqdn = 0; /* if 1, return pascal string (03 draft) */
char *subj = NULL;
ip6 = mtod(m, struct ip6_hdr *);
#ifndef PULLDOWN_TEST
ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
#else
IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
if (ni6 == NULL) {
/* m is already reclaimed */
return NULL;
}
#endif
/*
* Validate IPv6 source address.
* The default configuration MUST be to refuse answering queries from
* global-scope addresses according to RFC4602.
* Notes:
* - it's not very clear what "refuse" means; this implementation
* simply drops it.
* - it's not very easy to identify global-scope (unicast) addresses
* since there are many prefixes for them. It should be safer
* and in practice sufficient to check "all" but loopback and
* link-local (note that site-local unicast was deprecated and
* ULA is defined as global scope-wise)
*/
if ((icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
!IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src)) {
goto bad;
}
/*
* Validate IPv6 destination address.
*
* The Responder must discard the Query without further processing
* unless it is one of the Responder's unicast or anycast addresses, or
* a link-local scope multicast address which the Responder has joined.
* [RFC4602, Section 5.]
*/
if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst) &&
!IN6_IS_ADDR_MC_UNICAST_BASED_LINKLOCAL(&ip6->ip6_dst)) {
goto bad;
}
/* else it's a link-local multicast, fine */
} else { /* unicast or anycast */
uint32_t ia6_flags;
if (ip6_getdstifaddr_info(m, NULL, &ia6_flags) != 0) {
goto bad; /* XXX impossible */
}
if ((ia6_flags & IN6_IFF_TEMPORARY) &&
!(icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
nd6log(debug, "ni6_input: ignore node info to a temporary address in %s:%d",
__func__, __LINE__);
goto bad;
}
}
/* validate query Subject field. */
qtype = ntohs(ni6->ni_qtype);
subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
switch (qtype) {
case NI_QTYPE_NOOP:
case NI_QTYPE_SUPTYPES:
/* 07 draft */
if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0) {
break;
}
OS_FALLTHROUGH;
case NI_QTYPE_FQDN:
case NI_QTYPE_NODEADDR:
case NI_QTYPE_IPV4ADDR:
switch (ni6->ni_code) {
case ICMP6_NI_SUBJ_IPV6:
#if ICMP6_NI_SUBJ_IPV6 != 0
case 0:
#endif
/*
* backward compatibility - try to accept 03 draft
* format, where no Subject is present.
*/
if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
subjlen == 0) {
oldfqdn++;
break;
}
#if ICMP6_NI_SUBJ_IPV6 != 0
if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6) {
goto bad;
}
#endif
if (subjlen != sizeof(struct in6_addr)) {
goto bad;
}
/*
* Validate Subject address.
*
* Not sure what exactly "address belongs to the node"
* means in the spec, is it just unicast, or what?
*
* At this moment we consider Subject address as
* "belong to the node" if the Subject address equals
* to the IPv6 destination address; validation for
* IPv6 destination address should have done enough
* check for us.
*
* We do not do proxy at this moment.
*/
/* m_pulldown instead of copy? */
m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
subjlen, (caddr_t)&sin6.sin6_addr);
sin6.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
&sin6.sin6_addr);
in6_embedscope(&sin6.sin6_addr, &sin6, NULL, NULL,
NULL);
bzero(&sin6_d, sizeof(sin6_d));
sin6_d.sin6_family = AF_INET6; /* not used, actually */
sin6_d.sin6_len = sizeof(sin6_d); /* ditto */
sin6_d.sin6_addr = ip6->ip6_dst;
sin6_d.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
&ip6->ip6_dst);
in6_embedscope(&sin6_d.sin6_addr, &sin6_d, NULL, NULL,
NULL);
subj = (char *)&sin6;
if (SA6_ARE_ADDR_EQUAL(&sin6, &sin6_d)) {
break;
}
/*
* XXX if we are to allow other cases, we should really
* be careful about scope here.
* basically, we should disallow queries toward IPv6
* destination X with subject Y,
* if scope(X) > scope(Y).
* if we allow scope(X) > scope(Y), it will result in
* information leakage across scope boundary.
*/
goto bad;
case ICMP6_NI_SUBJ_FQDN:
/*
* Validate Subject name with gethostname(3).
*
* The behavior may need some debate, since:
* - we are not sure if the node has FQDN as
* hostname (returned by gethostname(3)).
* - the code does wildcard match for truncated names.
* however, we are not sure if we want to perform
* wildcard match, if gethostname(3) side has
* truncated hostname.
*/
lck_mtx_lock(&hostname_lock);
n = ni6_nametodns(hostname, hostnamelen, 0);
lck_mtx_unlock(&hostname_lock);
if (!n || n->m_next || n->m_len == 0) {
goto bad;
}
IP6_EXTHDR_GET(subj, char *, m,
off + sizeof(struct icmp6_nodeinfo), subjlen);
if (subj == NULL) {
goto bad;
}
if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
n->m_len)) {
goto bad;
}
m_freem(n);
n = NULL;
break;
case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */
default:
goto bad;
}
break;
}
/* refuse based on configuration. XXX ICMP6_NI_REFUSED? */
switch (qtype) {
case NI_QTYPE_FQDN:
if ((icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0) {
goto bad;
}
break;
case NI_QTYPE_NODEADDR:
case NI_QTYPE_IPV4ADDR:
if ((icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0) {
goto bad;
}
break;
}
/* guess reply length */
switch (qtype) {
case NI_QTYPE_NOOP:
break; /* no reply data */
case NI_QTYPE_SUPTYPES:
replylen += sizeof(u_int32_t);
break;
case NI_QTYPE_FQDN:
/* XXX will append an mbuf */
replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
break;
case NI_QTYPE_NODEADDR:
addrs = ni6_addrs(ni6, &ifp, subj);
if ((replylen += addrs * (sizeof(struct in6_addr) +
sizeof(u_int32_t))) > MCLBYTES) {
replylen = MCLBYTES; /* XXX: will truncate pkt later */
}
break;
case NI_QTYPE_IPV4ADDR:
/* unsupported - should respond with unknown Qtype? */
break;
default:
/*
* XXX: We must return a reply with the ICMP6 code
* `unknown Qtype' in this case. However we regard the case
* as an FQDN query for backward compatibility.
* Older versions set a random value to this field,
* so it rarely varies in the defined qtypes.
* But the mechanism is not reliable...
* maybe we should obsolete older versions.
*/
qtype = NI_QTYPE_FQDN;
/* XXX will append an mbuf */
replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
oldfqdn++;
break;
}
/* allocate an mbuf to reply. */
MGETHDR(n, M_DONTWAIT, m->m_type); /* MAC-OK */
if (n == NULL) {
m_freem(m);
if (ifp != NULL) {
ifnet_release(ifp);
}
return NULL;
}
M_COPY_PKTHDR(n, m); /* just for recvif */
if (replylen > MHLEN) {
if (replylen > MCLBYTES) {
/*
* XXX: should we try to allocate more? But MCLBYTES
* is probably much larger than IPV6_MMTU...
*/
goto bad;
}
MCLGET(n, M_DONTWAIT);
if ((n->m_flags & M_EXT) == 0) {
goto bad;
}
}
n->m_pkthdr.len = n->m_len = replylen;
/* copy mbuf header and IPv6 + Node Information base headers */
bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
/* qtype dependent procedure */
switch (qtype) {
case NI_QTYPE_NOOP:
nni6->ni_code = ICMP6_NI_SUCCESS;
nni6->ni_flags = 0;
break;
case NI_QTYPE_SUPTYPES:
{
u_int32_t v;
nni6->ni_code = ICMP6_NI_SUCCESS;
nni6->ni_flags = htons(0x0000); /* raw bitmap */
/* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
v = (u_int32_t)htonl(0x0000000f);
bcopy(&v, nni6 + 1, sizeof(u_int32_t));
break;
}
case NI_QTYPE_FQDN:
nni6->ni_code = ICMP6_NI_SUCCESS;
fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
sizeof(struct ip6_hdr) +
sizeof(struct icmp6_nodeinfo));
nni6->ni_flags = 0; /* XXX: meaningless TTL */
fqdn->ni_fqdn_ttl = 0; /* ditto. */
/*
* XXX do we really have FQDN in variable "hostname"?
*/
lck_mtx_lock(&hostname_lock);
n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn);
lck_mtx_unlock(&hostname_lock);
if (n->m_next == NULL) {
goto bad;
}
/* XXX we assume that n->m_next is not a chain */
if (n->m_next->m_next != NULL) {
goto bad;
}
n->m_pkthdr.len += n->m_next->m_len;
break;
case NI_QTYPE_NODEADDR:
{
int lenlim, copied;
nni6->ni_code = ICMP6_NI_SUCCESS;
n->m_pkthdr.len = n->m_len =
sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
lenlim = (int)M_TRAILINGSPACE(n);
copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
/* XXX: reset mbuf length */
n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
sizeof(struct icmp6_nodeinfo) + copied;
break;
}
default:
break; /* XXX impossible! */
}
nni6->ni_type = ICMP6_NI_REPLY;
m_freem(m);
if (ifp != NULL) {
ifnet_release(ifp);
}
return n;
bad:
m_freem(m);
if (n) {
m_freem(n);
}
if (ifp != NULL) {
ifnet_release(ifp);
}
return NULL;
}
#undef hostnamelen
/*
* make a mbuf with DNS-encoded string. no compression support.
*
* XXX names with less than 2 dots (like "foo" or "foo.section") will be
* treated as truncated name (two \0 at the end). this is a wild guess.
*/
static struct mbuf *
ni6_nametodns(
const char *name,
uint32_t namelen,
int old) /* return pascal string if non-zero */
{
struct mbuf *m;
char *cp, *ep;
const char *p, *q;
int i, nterm;
uint32_t len;
if (old) {
len = namelen + 1;
} else {
len = MCLBYTES;
}
/* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
MGET(m, M_DONTWAIT, MT_DATA);
if (m && len > MLEN) {
MCLGET(m, M_DONTWAIT);
if ((m->m_flags & M_EXT) == 0) {
goto fail;
}
}
if (!m) {
goto fail;
}
m->m_next = NULL;
if (old) {
m->m_len = len;
*mtod(m, char *) = (char)namelen;
bcopy(name, mtod(m, char *) + 1, namelen);
return m;
} else {
m->m_len = 0;
cp = mtod(m, char *);
ep = mtod(m, char *) + M_TRAILINGSPACE(m);
/* if not certain about my name, return empty buffer */
if (namelen == 0) {
return m;
}
/*
* guess if it looks like shortened hostname, or FQDN.
* shortened hostname needs two trailing "\0".
*/
i = 0;
for (p = name; p < name + namelen; p++) {
if (*p && *p == '.') {
i++;
}
}
if (i < 2) {
nterm = 2;
} else {
nterm = 1;
}
p = name;
while (cp < ep && p < name + namelen) {
i = 0;
for (q = p; q < name + namelen && *q && *q != '.'; q++) {
i++;
}
/* result does not fit into mbuf */
if (cp + i + 1 >= ep) {
goto fail;
}
/*
* DNS label length restriction, RFC1035 page 8.
* "i == 0" case is included here to avoid returning
* 0-length label on "foo..bar".
*/
if (i <= 0 || i >= 64) {
goto fail;
}
*cp++ = (char)i;
bcopy(p, cp, i);
cp += i;
p = q;
if (p < name + namelen && *p == '.') {
p++;
}
}
/* termination */
if (cp + nterm >= ep) {
goto fail;
}
while (nterm-- > 0) {
*cp++ = '\0';
}
m->m_len = (int32_t)(cp - mtod(m, char *));
return m;
}
panic("should not reach here");
/* NOTREACHED */
fail:
if (m) {
m_freem(m);
}
return NULL;
}
/*
* check if two DNS-encoded string matches. takes care of truncated
* form (with \0\0 at the end). no compression support.
* XXX upper/lowercase match (see RFC2065)
*/
static int
ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
{
const char *a0, *b0;
int l;
/* simplest case - need validation? */
if (alen == blen && bcmp(a, b, alen) == 0) {
return 1;
}
a0 = a;
b0 = b;
/* termination is mandatory */
if (alen < 2 || blen < 2) {
return 0;
}
if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0') {
return 0;
}
alen--;
blen--;
while (a - a0 < alen && b - b0 < blen) {
if (a - a0 + 1 > alen || b - b0 + 1 > blen) {
return 0;
}
if ((signed char)a[0] < 0 || (signed char)b[0] < 0) {
return 0;
}
/* we don't support compression yet */
if (a[0] >= 64 || b[0] >= 64) {
return 0;
}
/* truncated case */
if (a[0] == 0 && a - a0 == alen - 1) {
return 1;
}
if (b[0] == 0 && b - b0 == blen - 1) {
return 1;
}
if (a[0] == 0 || b[0] == 0) {
return 0;
}
if (a[0] != b[0]) {
return 0;
}
l = a[0];
if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen) {
return 0;
}
if (bcmp(a + 1, b + 1, l) != 0) {
return 0;
}
a += 1 + l;
b += 1 + l;
}
if (a - a0 == alen && b - b0 == blen) {
return 1;
} else {
return 0;
}
}
/*
* calculate the number of addresses to be returned in the node info reply.
*/
static int
ni6_addrs(struct icmp6_nodeinfo *ni6, struct ifnet **ifpp, char *subj)
{
struct ifnet *ifp;
struct in6_ifaddr *ifa6;
struct ifaddr *ifa;
struct sockaddr_in6 *subj_ip6 = NULL; /* XXX pedant */
int addrs = 0, addrsofif, iffound = 0;
int niflags = ni6->ni_flags;
if (ifpp != NULL) {
*ifpp = NULL;
}
if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
switch (ni6->ni_code) {
case ICMP6_NI_SUBJ_IPV6:
if (subj == NULL) { /* must be impossible... */
return 0;
}
subj_ip6 = (struct sockaddr_in6 *)(void *)subj;
break;
default:
/*
* XXX: we only support IPv6 subject address for
* this Qtype.
*/
return 0;
}
}
ifnet_head_lock_shared();
TAILQ_FOREACH(ifp, &ifnet_head, if_list) {
addrsofif = 0;
ifnet_lock_shared(ifp);
TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
{
IFA_LOCK(ifa);
if (ifa->ifa_addr->sa_family != AF_INET6) {
IFA_UNLOCK(ifa);
continue;
}
ifa6 = (struct in6_ifaddr *)ifa;
if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
IN6_ARE_ADDR_EQUAL(&subj_ip6->sin6_addr,
&ifa6->ia_addr.sin6_addr)) {
iffound = 1;
}
/*
* IPv4-mapped addresses can only be returned by a
* Node Information proxy, since they represent
* addresses of IPv4-only nodes, which perforce do
* not implement this protocol.
* [icmp-name-lookups-07, Section 5.4]
* So we don't support NI_NODEADDR_FLAG_COMPAT in
* this function at this moment.
*/
/* What do we have to do about ::1? */
switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
case IPV6_ADDR_SCOPE_LINKLOCAL:
if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) {
IFA_UNLOCK(ifa);
continue;
}
break;
case IPV6_ADDR_SCOPE_SITELOCAL:
if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) {
IFA_UNLOCK(ifa);
continue;
}
break;
case IPV6_ADDR_SCOPE_GLOBAL:
if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) {
IFA_UNLOCK(ifa);
continue;
}
break;
default:
IFA_UNLOCK(ifa);
continue;
}
/*
* check if anycast is okay.
* XXX: just experimental. not in the spec.
*/
if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
(niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) {
IFA_UNLOCK(ifa);
continue; /* we need only unicast addresses */
}
if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
(icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
IFA_UNLOCK(ifa);
continue;
}
addrsofif++; /* count the address */
IFA_UNLOCK(ifa);
}
ifnet_lock_done(ifp);
if (iffound) {
if (ifpp != NULL) {
*ifpp = ifp;
ifnet_reference(ifp);
}
ifnet_head_done();
return addrsofif;
}
addrs += addrsofif;
}
ifnet_head_done();
return addrs;
}
static int
ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
struct ifnet *ifp0, int resid)
{
struct ifnet *ifp = ifp0;
struct in6_ifaddr *ifa6;
struct ifaddr *ifa;
struct ifnet *ifp_dep = NULL;
int copied = 0, allow_deprecated = 0;
u_char *cp = (u_char *)(nni6 + 1);
int niflags = ni6->ni_flags;
u_int32_t ltime;
uint64_t now = net_uptime();
if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL)) {
return 0; /* needless to copy */
}
again:
ifnet_head_lock_shared();
if (ifp == NULL) {
ifp = TAILQ_FIRST(&ifnet_head);
}
for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
ifnet_lock_shared(ifp);
for (ifa = ifp->if_addrlist.tqh_first; ifa;
ifa = ifa->ifa_list.tqe_next) {
struct in6_addrlifetime_i *lt;
IFA_LOCK(ifa);
if (ifa->ifa_addr->sa_family != AF_INET6) {
IFA_UNLOCK(ifa);
continue;
}
ifa6 = (struct in6_ifaddr *)ifa;
if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
allow_deprecated == 0) {
/*
* prefererred address should be put before
* deprecated addresses.
*/
/* record the interface for later search */
if (ifp_dep == NULL) {
ifp_dep = ifp;
}
IFA_UNLOCK(ifa);
continue;
} else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
allow_deprecated != 0) {
IFA_UNLOCK(ifa);
continue; /* we now collect deprecated addrs */
}
/* What do we have to do about ::1? */
switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
case IPV6_ADDR_SCOPE_LINKLOCAL:
if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0) {
IFA_UNLOCK(ifa);
continue;
}
break;
case IPV6_ADDR_SCOPE_SITELOCAL:
if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0) {
IFA_UNLOCK(ifa);
continue;
}
break;
case IPV6_ADDR_SCOPE_GLOBAL:
if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0) {
IFA_UNLOCK(ifa);
continue;
}
break;
default:
IFA_UNLOCK(ifa);
continue;
}
/*
* check if anycast is okay.
* XXX: just experimental. not in the spec.
*/
if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
(niflags & NI_NODEADDR_FLAG_ANYCAST) == 0) {
IFA_UNLOCK(ifa);
continue;
}
if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
(icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
IFA_UNLOCK(ifa);
continue;
}
/* now we can copy the address */
if (resid < sizeof(struct in6_addr) +
sizeof(u_int32_t)) {
IFA_UNLOCK(ifa);
/*
* We give up much more copy.
* Set the truncate flag and return.
*/
nni6->ni_flags |=
NI_NODEADDR_FLAG_TRUNCATE;
ifnet_lock_done(ifp);
ifnet_head_done();
return copied;
}
/*
* Set the TTL of the address.
* The TTL value should be one of the following
* according to the specification:
*
* 1. The remaining lifetime of a DHCP lease on the
* address, or
* 2. The remaining Valid Lifetime of a prefix from
* which the address was derived through Stateless
* Autoconfiguration.
*
* Note that we currently do not support stateful
* address configuration by DHCPv6, so the former
* case can't happen.
*/
lt = &ifa6->ia6_lifetime;
if (lt->ia6ti_expire == 0) {
ltime = ND6_INFINITE_LIFETIME;
} else {
if (lt->ia6ti_expire > now) {
ltime = htonl((uint32_t)(lt->ia6ti_expire - now));
} else {
ltime = 0;
}
}
bcopy(&ltime, cp, sizeof(u_int32_t));
cp += sizeof(u_int32_t);
/* copy the address itself */
bcopy(&ifa6->ia_addr.sin6_addr, cp,
sizeof(struct in6_addr));
/* XXX: KAME link-local hack; remove ifindex */
if (IN6_IS_ADDR_LINKLOCAL(&ifa6->ia_addr.sin6_addr)) {
((struct in6_addr *)(void *)cp)->s6_addr16[1] = 0;
}
cp += sizeof(struct in6_addr);
resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
copied += (sizeof(struct in6_addr) +
sizeof(u_int32_t));
IFA_UNLOCK(ifa);
}
ifnet_lock_done(ifp);
if (ifp0) { /* we need search only on the specified IF */
break;
}
}
ifnet_head_done();
if (allow_deprecated == 0 && ifp_dep != NULL) {
ifp = ifp_dep;
allow_deprecated = 1;
goto again;
}
return copied;
}
/*
* XXX almost dup'ed code with rip6_input.
*/
static int
icmp6_rip6_input(struct mbuf **mp, int off)
{
struct mbuf *m = *mp;
struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
struct in6pcb *in6p;
struct in6pcb *last = NULL;
struct sockaddr_in6 rip6src;
struct icmp6_hdr *icmp6;
struct mbuf *opts = NULL;
int ret = 0;
struct ifnet *ifp = m->m_pkthdr.rcvif;
#ifndef PULLDOWN_TEST
/* this is assumed to be safe. */
icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
#else
IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
if (icmp6 == NULL) {
/* m is already reclaimed */
return IPPROTO_DONE;
}
#endif
/*
* XXX: the address may have embedded scope zone ID, which should be
* hidden from applications.
*/
bzero(&rip6src, sizeof(rip6src));
rip6src.sin6_family = AF_INET6;
rip6src.sin6_len = sizeof(struct sockaddr_in6);
rip6src.sin6_addr = ip6->ip6_src;
if (sa6_recoverscope(&rip6src, TRUE)) {
return IPPROTO_DONE;
}
lck_rw_lock_shared(ripcbinfo.ipi_lock);
LIST_FOREACH(in6p, &ripcb, inp_list)
{
if ((in6p->inp_vflag & INP_IPV6) == 0) {
continue;
}
if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6) {
continue;
}
if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
!IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst)) {
continue;
}
if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
!IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src)) {
continue;
}
if (in6p->in6p_icmp6filt
&& ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
in6p->in6p_icmp6filt)) {
continue;
}
if (inp_restricted_recv(in6p, ifp)) {
continue;
}
if (last) {
struct mbuf *n;
if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
if ((last->in6p_flags & INP_CONTROLOPTS) != 0 ||
#if CONTENT_FILTER
/* Content Filter needs to see local address */
(last->in6p_socket->so_cfil_db != NULL) ||
#endif
(last->in6p_socket->so_options & SO_TIMESTAMP) != 0 ||
(last->in6p_socket->so_options & SO_TIMESTAMP_MONOTONIC) != 0 ||
(last->in6p_socket->so_options & SO_TIMESTAMP_CONTINUOUS) != 0) {
ret = ip6_savecontrol(last, n, &opts);
if (ret != 0) {
m_freem(n);
m_freem(opts);
last = in6p;
continue;
}
}
/* strip intermediate headers */
m_adj(n, off);
so_recv_data_stat(last->in6p_socket, m, 0);
if (sbappendaddr(&last->in6p_socket->so_rcv,
(struct sockaddr *)&rip6src,
n, opts, NULL) != 0) {
sorwakeup(last->in6p_socket);
}
opts = NULL;
}
}
last = in6p;
}
if (last) {
if ((last->in6p_flags & INP_CONTROLOPTS) != 0 ||
#if CONTENT_FILTER
/* Content Filter needs to see local address */
(last->in6p_socket->so_cfil_db != NULL) ||
#endif
(last->in6p_socket->so_options & SO_TIMESTAMP) != 0 ||
(last->in6p_socket->so_options & SO_TIMESTAMP_MONOTONIC) != 0 ||
(last->in6p_socket->so_options & SO_TIMESTAMP_CONTINUOUS) != 0) {
ret = ip6_savecontrol(last, m, &opts);
if (ret != 0) {
goto error;
}
}
/* strip intermediate headers */
m_adj(m, off);
so_recv_data_stat(last->in6p_socket, m, 0);
if (sbappendaddr(&last->in6p_socket->so_rcv,
(struct sockaddr *)&rip6src, m, opts, NULL) != 0) {
sorwakeup(last->in6p_socket);
}
} else {
goto error;
}
lck_rw_done(ripcbinfo.ipi_lock);
return IPPROTO_DONE;
error:
lck_rw_done(ripcbinfo.ipi_lock);
m_freem(m);
m_freem(opts);
ip6stat.ip6s_delivered--;
return IPPROTO_DONE;
}
/*
* Reflect the ip6 packet back to the source.
* OFF points to the icmp6 header, counted from the top of the mbuf.
*/
void
icmp6_reflect(struct mbuf *m, size_t off)
{
struct mbuf *m_ip6hdr = m;
struct ip6_hdr *ip6;
struct icmp6_hdr *icmp6;
struct in6_ifaddr *ia;
struct in6_addr t, src_storage, *src = 0;
int plen;
int type, code;
struct ifnet *outif = NULL;
struct sockaddr_in6 sa6_src, sa6_dst;
struct nd_ifinfo *ndi = NULL;
u_int32_t oflow;
struct ip6_out_args ip6oa;
bzero(&ip6oa, sizeof(ip6oa));
ip6oa.ip6oa_boundif = IFSCOPE_NONE;
ip6oa.ip6oa_flags = IP6OAF_SELECT_SRCIF | IP6OAF_BOUND_SRCADDR |
IP6OAF_INTCOPROC_ALLOWED | IP6OAF_AWDL_UNRESTRICTED;
ip6oa.ip6oa_sotc = SO_TC_UNSPEC;
ip6oa.ip6oa_netsvctype = _NET_SERVICE_TYPE_UNSPEC;
if (!(m->m_pkthdr.pkt_flags & PKTF_LOOP) && m->m_pkthdr.rcvif != NULL) {
ip6oa.ip6oa_boundif = m->m_pkthdr.rcvif->if_index;
ip6oa.ip6oa_flags |= IP6OAF_BOUND_IF;
}
/* too short to reflect */
if (off < sizeof(struct ip6_hdr)) {
nd6log(debug,
"sanity fail: off=%x, sizeof(ip6)=%x in %s:%d\n",
(u_int32_t)off, (u_int32_t)sizeof(struct ip6_hdr),
__func__, __LINE__);
goto bad;
}
/*
* 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, (int)l);
l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
if (m->m_len < l) {
if ((m_ip6hdr = m_pulldown(m, 0, (int)l, NULL)) == NULL) {
return;
}
}
bcopy((caddr_t)&nip6, mtod(m, caddr_t), 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_ip6hdr = m_pulldown(m, 0, (int)l, NULL)) == NULL) {
return;
}
}
}
plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
ip6 = mtod(m_ip6hdr, struct ip6_hdr *);
ip6->ip6_nxt = IPPROTO_ICMPV6;
icmp6 = (struct icmp6_hdr *)(ip6 + 1);
type = icmp6->icmp6_type; /* keep type for statistics */
code = icmp6->icmp6_code; /* ditto. */
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.
*/
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;
in6_recoverscope(&sa6_src, &ip6->ip6_dst, m->m_pkthdr.rcvif);
in6_embedscope(&ip6->ip6_dst, &sa6_src, NULL, NULL, NULL);
bzero(&sa6_dst, sizeof(sa6_dst));
sa6_dst.sin6_family = AF_INET6;
sa6_dst.sin6_len = sizeof(sa6_dst);
sa6_dst.sin6_addr = t;
in6_recoverscope(&sa6_dst, &t, m->m_pkthdr.rcvif);
in6_embedscope(&t, &sa6_dst, NULL, NULL, NULL);
/*
* If the incoming packet was addressed directly to us(i.e. unicast),
* use dst as the src for the reply.
* The IN6_IFF_NOTREADY case should be VERY rare, but is possible
* (for example) when we encounter an error while forwarding procedure
* destined to a duplicated address of ours.
* Note that ip6_getdstifaddr() may fail if we are in an error handling
* procedure of an outgoing packet of our own, in which case we need
* to search in the ifaddr list.
*/
lck_rw_lock_shared(&in6_ifaddr_rwlock);
TAILQ_FOREACH(ia, IN6ADDR_HASH(&t), ia6_hash) {
IFA_LOCK(&ia->ia_ifa);
if (IN6_ARE_ADDR_EQUAL(&t, &ia->ia_addr.sin6_addr) &&
(ia->ia6_flags & (IN6_IFF_ANYCAST | IN6_IFF_NOTREADY | IN6_IFF_CLAT46)) == 0) {
IFA_UNLOCK(&ia->ia_ifa);
src = &t;
break;
}
IFA_UNLOCK(&ia->ia_ifa);
}
lck_rw_done(&in6_ifaddr_rwlock);
if (ia == NULL && IN6_IS_ADDR_LINKLOCAL(&t) &&
((m->m_flags & M_LOOP) || (m->m_pkthdr.pkt_flags & PKTF_LOOP))) {
/*
* This is the case if the dst is our link-local address
* and the sender is also ourselves. Here we test for both
* M_LOOP and PKTF_LOOP, since the former may have been set
* in ip6_output() and that we get here as part of callling
* ip6_process_hopopts(). See comments in <sys/mbuf.h>
*/
src = &t;
}
if (src == NULL) {
int e;
struct sockaddr_in6 sin6;
struct route_in6 ro;
/*
* 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.
*/
bzero(&sin6, sizeof(sin6));
sin6.sin6_family = AF_INET6;
sin6.sin6_len = sizeof(sin6);
sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */
bzero(&ro, sizeof(ro));
/*
* in6_selectsrc() might return outif with its reference held
* even in the error case, so we always need to release it
* if non-NULL.
*/
src = in6_selectsrc(&sin6, NULL, NULL, &ro, &outif,
&src_storage, ip6oa.ip6oa_boundif, &e);
ROUTE_RELEASE(&ro);
if (src == NULL) {
nd6log(debug,
"icmp6_reflect: source can't be determined: "
"dst=%s, error=%d\n",
ip6_sprintf(&sa6_src.sin6_addr), e);
goto bad;
}
}
oflow = ip6->ip6_flow; /* Save for later */
ip6->ip6_src = *src;
ip6->ip6_flow = 0;
ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
ip6->ip6_vfc |= IPV6_VERSION;
if (icmp6->icmp6_type == ICMP6_ECHO_REPLY && icmp6->icmp6_code == 0) {
ip6->ip6_flow |= (oflow & htonl(0x0ff00000));
}
ip6->ip6_nxt = IPPROTO_ICMPV6;
if (outif != NULL && (ndi = ND_IFINFO(outif)) != NULL &&
ndi->initialized) {
lck_mtx_lock(&ndi->lock);
ip6->ip6_hlim = ndi->chlim;
lck_mtx_unlock(&ndi->lock);
}
if (m->m_pkthdr.rcvif != NULL &&
(ndi = ND_IFINFO(m->m_pkthdr.rcvif)) != NULL &&
ndi->initialized) {
/* XXX: This may not be the outgoing interface */
lck_mtx_lock(&ndi->lock);
ip6->ip6_hlim = ndi->chlim;
lck_mtx_unlock(&ndi->lock);
} else {
ip6->ip6_hlim = (uint8_t)ip6_defhlim;
}
/* Use the same traffic class as in the request to match IPv4 */
icmp6->icmp6_cksum = 0;
icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
sizeof(struct ip6_hdr), plen);
/*
* XXX option handling
*/
m->m_flags &= ~(M_BCAST | M_MCAST);
if (outif != NULL) {
ifnet_release(outif);
outif = NULL;
}
m->m_pkthdr.csum_data = 0;
m->m_pkthdr.csum_flags = 0;
ip6_output(m, NULL, NULL, IPV6_OUTARGS, NULL, &outif, &ip6oa);
if (outif != NULL) {
icmp6_ifoutstat_inc(outif, type, code);
ifnet_release(outif);
}
return;
bad:
m_freem(m);
if (outif != NULL) {
ifnet_release(outif);
}
return;
}
static const char *
icmp6_redirect_diag(struct in6_addr *src6,
struct in6_addr *dst6,
struct in6_addr *tgt6)
{
static char buf[1024];
snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
ip6_sprintf(src6), ip6_sprintf(dst6), ip6_sprintf(tgt6));
return buf;
}
void
icmp6_redirect_input(struct mbuf *m, int off, int icmp6len)
{
struct ifnet *ifp = NULL;
struct ip6_hdr *ip6 = NULL;
struct nd_redirect *nd_rd = NULL;
char *lladdr = NULL;
int lladdrlen = 0;
u_char *redirhdr = NULL;
int redirhdrlen = 0;
struct rtentry *rt = NULL;
int is_router = 0;
int is_onlink = 0;
struct in6_addr src6 = {};
struct in6_addr redtgt6 = {};
struct in6_addr reddst6 = {};
union nd_opts ndopts = {};
if (m == NULL) {
return;
}
ifp = m->m_pkthdr.rcvif;
if (ifp == NULL) {
goto freeit;
}
/*
* If we are an advertising router on this interface,
* don't update route by icmp6 redirect.
*/
if (ifp->if_ipv6_router_mode == IPV6_ROUTER_MODE_EXCLUSIVE) {
goto freeit;
}
if (!icmp6_rediraccept) {
goto freeit;
}
ip6 = mtod(m, struct ip6_hdr *);
src6 = ip6->ip6_src;
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, icmp6len, return );
nd_rd = (struct nd_redirect *)(mtod(m, caddr_t) + off);
#else
IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
if (nd_rd == NULL) {
icmp6stat.icp6s_tooshort++;
goto freeit;
}
#endif
ip6 = mtod(m, struct ip6_hdr *);
redtgt6 = nd_rd->nd_rd_target;
reddst6 = nd_rd->nd_rd_dst;
if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
goto freeit;
}
/* validation */
if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
nd6log(error,
"ICMP6 redirect sent from %s rejected; "
"must be from linklocal\n", ip6_sprintf(&src6));
goto bad;
}
if (ip6->ip6_hlim != IPV6_MAXHLIM) {
nd6log(error,
"ICMP6 redirect sent from %s rejected; "
"hlim=%d (must be 255)\n",
ip6_sprintf(&src6), ip6->ip6_hlim);
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);
bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
rt = rtalloc1_scoped((struct sockaddr *)&sin6, 0, 0, ifp->if_index);
if (rt) {
RT_LOCK(rt);
if (rt->rt_gateway == NULL ||
rt->rt_gateway->sa_family != AF_INET6) {
nd6log(error,
"ICMP6 redirect rejected; no route "
"with inet6 gateway found for redirect dst: %s\n",
icmp6_redirect_diag(&src6, &reddst6, &redtgt6));
RT_UNLOCK(rt);
rtfree(rt);
goto bad;
}
gw6 = &(((struct sockaddr_in6 *)(void *)
rt->rt_gateway)->sin6_addr);
if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
nd6log(error,
"ICMP6 redirect rejected; "
"not equal to gw-for-src=%s (must be same): "
"%s\n",
ip6_sprintf(gw6),
icmp6_redirect_diag(&src6, &reddst6, &redtgt6));
RT_UNLOCK(rt);
rtfree(rt);
goto bad;
}
} else {
nd6log(error,
"ICMP6 redirect rejected; "
"no route found for redirect dst: %s\n",
icmp6_redirect_diag(&src6, &reddst6, &redtgt6));
goto bad;
}
RT_UNLOCK(rt);
rtfree(rt);
rt = NULL;
}
if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
nd6log(error,
"ICMP6 redirect rejected; "
"redirect dst must be unicast: %s\n",
icmp6_redirect_diag(&src6, &reddst6, &redtgt6));
goto bad;
}
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(error,
"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);
nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
if (nd6_options(&ndopts) < 0) {
nd6log(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 (ndopts.nd_opts_rh) {
redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
}
if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
nd6log(info,
"icmp6_redirect_input: lladdrlen mismatch for %s "
"(if %d, icmp6 packet %d): %s\n",
ip6_sprintf(&redtgt6), 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;
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);
bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
rtredirect(ifp, (struct sockaddr *)&sdst,
(struct sockaddr *)&sgw, NULL, RTF_GATEWAY | RTF_HOST,
(struct sockaddr *)&ssrc, NULL);
}
/* 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);
bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
#if IPSEC
key_sa_routechange((struct sockaddr *)&sdst);
#endif
}
freeit:
m_freem(m);
return;
bad:
icmp6stat.icp6s_badredirect++;
m_freem(m);
}
void
icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
{
struct ifnet *ifp; /* my outgoing interface */
struct in6_addr ifp_ll6;
struct in6_addr *router_ll6;
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 ifnet *outif = NULL;
struct sockaddr_in6 src_sa;
struct ip6_out_args ip6oa;
bzero(&ip6oa, sizeof(ip6oa));
ip6oa.ip6oa_boundif = IFSCOPE_NONE;
ip6oa.ip6oa_flags = IP6OAF_SELECT_SRCIF | IP6OAF_BOUND_SRCADDR;
ip6oa.ip6oa_sotc = SO_TC_UNSPEC;
ip6oa.ip6oa_netsvctype = _NET_SERVICE_TYPE_UNSPEC;
icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
if (rt != NULL) {
RT_LOCK(rt);
}
/* sanity check */
if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp)) {
goto fail;
}
/*
* If we are not a router to begin with, or not an advertising
* router on this interface, don't send icmp6 redirect.
*/
if (!ip6_forwarding || ifp->if_ipv6_router_mode != IPV6_ROUTER_MODE_EXCLUSIVE) {
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, &sip6->ip6_src);
RT_UNLOCK(rt);
if (nd6_is_addr_neighbor(&src_sa, ifp, 0) == 0) {
/* already unlocked */
rt = NULL;
goto fail;
}
RT_LOCK(rt);
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); /* MAC-OK */
if (m && IPV6_MMTU >= MHLEN) {
MCLGET(m, M_DONTWAIT);
}
if (!m) {
goto fail;
}
m->m_pkthdr.rcvif = NULL;
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 *ia;
if ((ia = in6ifa_ifpforlinklocal(ifp,
IN6_IFF_NOTREADY |
IN6_IFF_ANYCAST)) == NULL) {
goto fail;
}
IFA_LOCK(&ia->ia_ifa);
ifp_ll6 = ia->ia_addr.sin6_addr;
IFA_UNLOCK(&ia->ia_ifa);
IFA_REMREF(&ia->ia_ifa);
}
/* get ip6 linklocal address for the router. */
if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
struct sockaddr_in6 *sin6;
sin6 = (struct sockaddr_in6 *)(void *)rt->rt_gateway;
router_ll6 = &sin6->sin6_addr;
if (!IN6_IS_ADDR_LINKLOCAL(router_ll6)) {
router_ll6 = (struct in6_addr *)NULL;
}
} else {
router_ll6 = (struct in6_addr *)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 = IPV6_MAXHLIM;
/* 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 (!router_ll6) {
goto fail;
}
bcopy(router_ll6, &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 */
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));
}
RT_UNLOCK(rt);
rt = NULL;
p = (u_char *)(nd_rd + 1);
if (!router_ll6) {
goto nolladdropt;
}
{
/* target lladdr option */
struct rtentry *rt_router = NULL;
int len;
struct sockaddr_dl *sdl;
struct nd_opt_hdr *nd_opt;
char *lladdr;
/* Callee returns a locked route upon success */
rt_router = nd6_lookup(router_ll6, 0, ifp, 0);
if (!rt_router) {
goto nolladdropt;
}
RT_LOCK_ASSERT_HELD(rt_router);
len = sizeof(*nd_opt) + ifp->if_addrlen;
len = (len + 7) & ~7; /* round by 8 */
/* safety check */
if (len + (p - (u_char *)ip6) > maxlen) {
RT_REMREF_LOCKED(rt_router);
RT_UNLOCK(rt_router);
goto nolladdropt;
}
if (!(rt_router->rt_flags & RTF_GATEWAY) &&
(rt_router->rt_flags & RTF_LLINFO) &&
(rt_router->rt_gateway->sa_family == AF_LINK) &&
(sdl = (struct sockaddr_dl *)(void *)
rt_router->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 = (uint8_t)(len >> 3);
lladdr = (char *)(nd_opt + 1);
bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen);
p += len;
}
RT_REMREF_LOCKED(rt_router);
RT_UNLOCK(rt_router);
}
nolladdropt:;
m->m_pkthdr.len = m->m_len = (int32_t)(p - (u_char *)ip6);
/* just to be safe */
#ifdef M_DECRYPTED /*not openbsd*/
if (m0->m_flags & M_DECRYPTED) {
goto noredhdropt;
}
#endif
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 = (int)(maxlen - (p - (u_char *)ip6));
len &= ~7;
/* This is just for simplicity. */
if (m0->m_pkthdr.len != m0->m_len) {
if (m0->m_next) {
m_freem(m0->m_next);
m0->m_next = NULL;
}
m0->m_pkthdr.len = m0->m_len;
}
/*
* 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 (m0->m_next || m0->m_pkthdr.len != m0->m_len) {
panic("assumption failed in %s:%d\n", __func__, __LINE__);
}
if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
/* not enough room, truncate */
m0->m_pkthdr.len = m0->m_len = len - sizeof(*nd_opt_rh);
} else {
/* enough room, pad or truncate */
size_t extra;
extra = m0->m_pkthdr.len % 8;
if (extra) {
/* pad if easy enough, truncate if not */
if (8 - extra <= M_TRAILINGSPACE(m0)) {
/* pad */
m0->m_len += (8 - extra);
m0->m_pkthdr.len += (8 - extra);
} else {
/* truncate */
m0->m_pkthdr.len -= extra;
m0->m_len -= extra;
}
}
len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
m0->m_pkthdr.len = m0->m_len = 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 = (uint8_t)(len >> 3);
p += sizeof(*nd_opt_rh);
m->m_pkthdr.len = m->m_len = (int32_t)(p - (u_char *)ip6);
/* connect m0 to m */
m->m_next = m0;
m->m_pkthdr.len = m->m_len + m0->m_len;
}
noredhdropt:;
/* XXX: clear embedded link IDs in the inner header */
in6_clearscope(&sip6->ip6_src);
in6_clearscope(&sip6->ip6_dst);
in6_clearscope(&nd_rd->nd_rd_target);
in6_clearscope(&nd_rd->nd_rd_dst);
ip6->ip6_plen = htons((uint16_t)(m->m_pkthdr.len - sizeof(struct ip6_hdr)));
nd_rd->nd_rd_cksum = 0;
nd_rd->nd_rd_cksum
= in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), ntohs(ip6->ip6_plen));
/* send the packet to outside... */
ip6oa.ip6oa_boundif = ifp->if_index;
ip6oa.ip6oa_flags |= IP6OAF_BOUND_IF;
ip6oa.ip6oa_flags |= IP6OAF_DONT_FRAG;
ip6_output(m, NULL, NULL, IPV6_OUTARGS, NULL, &outif, &ip6oa);
if (outif) {
icmp6_ifstat_inc(outif, ifs6_out_msg);
icmp6_ifstat_inc(outif, ifs6_out_redirect);
ifnet_release(outif);
}
icmp6stat.icp6s_outhist[ND_REDIRECT]++;
return;
fail:
if (rt != NULL) {
RT_UNLOCK(rt);
}
if (m) {
m_freem(m);
}
if (m0) {
m_freem(m0);
}
}
/*
* ICMPv6 socket option processing.
*/
int
icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
{
int error = 0;
size_t optlen;
struct inpcb *inp = sotoinpcb(so);
int level, op, optname;
if (sopt) {
level = sopt->sopt_level;
op = sopt->sopt_dir;
optname = sopt->sopt_name;
optlen = sopt->sopt_valsize;
} else {
level = op = optname = optlen = 0;
}
if (level != IPPROTO_ICMPV6) {
return EINVAL;
}
switch (op) {
case PRCO_SETOPT:
switch (optname) {
case ICMP6_FILTER:
{
struct icmp6_filter *p;
if (optlen != 0 && optlen != sizeof(*p)) {
error = EMSGSIZE;
break;
}
if (inp->in6p_icmp6filt == NULL) {
error = EINVAL;
break;
}
if (optlen == 0) {
/* According to RFC 3542, an installed filter can be
* cleared by issuing a setsockopt for ICMP6_FILTER
* with a zero length.
*/
ICMP6_FILTER_SETPASSALL(inp->in6p_icmp6filt);
} else {
error = sooptcopyin(sopt, inp->in6p_icmp6filt, optlen,
optlen);
}
break;
}
default:
error = ENOPROTOOPT;
break;
}
break;
case PRCO_GETOPT:
switch (optname) {
case ICMP6_FILTER:
{
if (inp->in6p_icmp6filt == NULL) {
error = EINVAL;
break;
}
error = sooptcopyout(sopt, inp->in6p_icmp6filt,
MIN(sizeof(struct icmp6_filter), optlen));
break;
}
default:
error = ENOPROTOOPT;
break;
}
break;
}
return error;
}
/*
* ICMPv6 socket datagram option processing.
*/
int
icmp6_dgram_ctloutput(struct socket *so, struct sockopt *sopt)
{
if (kauth_cred_issuser(so->so_cred)) {
return icmp6_ctloutput(so, sopt);
}
if (sopt->sopt_level == IPPROTO_ICMPV6) {
switch (sopt->sopt_name) {
case ICMP6_FILTER:
return icmp6_ctloutput(so, sopt);
default:
return EPERM;
}
}
if (sopt->sopt_level != IPPROTO_IPV6) {
return EINVAL;
}
switch (sopt->sopt_name) {
case IPV6_UNICAST_HOPS:
case IPV6_CHECKSUM:
case IPV6_V6ONLY:
case IPV6_USE_MIN_MTU:
case IPV6_RECVRTHDR:
case IPV6_RECVPKTINFO:
case IPV6_RECVHOPLIMIT:
case IPV6_PATHMTU:
case IPV6_PKTINFO:
case IPV6_HOPLIMIT:
case IPV6_HOPOPTS:
case IPV6_DSTOPTS:
case IPV6_MULTICAST_IF:
case IPV6_MULTICAST_HOPS:
case IPV6_MULTICAST_LOOP:
case IPV6_JOIN_GROUP:
case IPV6_LEAVE_GROUP:
case IPV6_PORTRANGE:
case IPV6_IPSEC_POLICY:
case IPV6_RECVTCLASS:
case IPV6_TCLASS:
case IPV6_2292PKTOPTIONS:
case IPV6_2292PKTINFO:
case IPV6_2292HOPLIMIT:
case IPV6_2292HOPOPTS:
case IPV6_2292DSTOPTS:
case IPV6_2292RTHDR:
case IPV6_BOUND_IF:
case IPV6_NO_IFT_CELLULAR:
return ip6_ctloutput(so, sopt);
default:
return EPERM;
}
}
__private_extern__ int
icmp6_dgram_send(struct socket *so, int flags, struct mbuf *m,
struct sockaddr *nam, struct mbuf *control, struct proc *p)
{
#pragma unused(flags, p)
int error = 0;
struct inpcb *inp = sotoinpcb(so);
struct icmp6_hdr *icmp6;
if (inp == NULL
#if NECP
|| (necp_socket_should_use_flow_divert(inp))
#endif /* NECP */
) {
error = (inp == NULL ? EINVAL : EPROTOTYPE);
goto bad;
}
if (kauth_cred_issuser(so->so_cred)) {
return rip6_output(m, so, SIN6(nam), control, 0);
}
/*
* For an ICMPv6 packet, we should know its type and code
*/
if (SOCK_PROTO(so) == IPPROTO_ICMPV6) {
if (m->m_len < sizeof(struct icmp6_hdr) &&
(m = m_pullup(m, sizeof(struct icmp6_hdr))) == NULL) {
error = ENOBUFS;
goto bad;
}
icmp6 = mtod(m, struct icmp6_hdr *);
/*
* Allow only to send echo request and node information request
* See RFC 2463 for Echo Request Message format
*/
if ((icmp6->icmp6_type == ICMP6_ECHO_REQUEST &&
icmp6->icmp6_code == 0) ||
(icmp6->icmp6_type == ICMP6_NI_QUERY &&
(icmp6->icmp6_code == ICMP6_NI_SUBJ_IPV6 ||
icmp6->icmp6_code == ICMP6_NI_SUBJ_FQDN))) {
/* Good */
;
} else {
error = EPERM;
goto bad;
}
}
return rip6_output(m, so, SIN6(nam), control, 0);
bad:
VERIFY(error != 0);
if (m != NULL) {
m_freem(m);
}
if (control != NULL) {
m_freem(control);
}
return error;
}
/* Like rip6_attach but without root privilege enforcement */
__private_extern__ int
icmp6_dgram_attach(struct socket *so, int proto, struct proc *p)
{
struct inpcb *inp;
int error;
inp = sotoinpcb(so);
if (inp) {
panic("icmp6_dgram_attach");
}
if (proto != IPPROTO_ICMPV6) {
return EINVAL;
}
error = soreserve(so, rip_sendspace, rip_recvspace);
if (error) {
return error;
}
error = in_pcballoc(so, &ripcbinfo, p);
if (error) {
return error;
}
inp = (struct inpcb *)so->so_pcb;
inp->inp_vflag |= INP_IPV6;
inp->in6p_ip6_nxt = IPPROTO_ICMPV6;
inp->in6p_hops = -1; /* use kernel default */
inp->in6p_cksum = -1;
MALLOC(inp->in6p_icmp6filt, struct icmp6_filter *,
sizeof(struct icmp6_filter), M_PCB, M_WAITOK);
if (inp->in6p_icmp6filt == NULL) {
return ENOMEM;
}
ICMP6_FILTER_SETPASSALL(inp->in6p_icmp6filt);
return 0;
}
/*
* 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 check necessary?
*/
static int
icmp6_ratelimit(
__unused const struct in6_addr *dst, /* not used at this moment */
const int type,
__unused const int code)
{
int ret;
ret = 0; /* okay to send */
/* PPS limit */
if (type == ND_ROUTER_ADVERT) {
if (!ppsratecheck(&icmp6rappslim_last, &icmp6rapps_count,
icmp6rappslim)) {
ret++;
}
} else if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count,
icmp6errppslim)) {
/*
* We add some randomness here to still generate ICMPv6 error
* post icmp6errppslim limit with a probability that goes down
* with increased value of icmp6errpps_count.
*/
if (icmp6errpps_count > 0 && icmp6errppslim > 0 &&
icmp6errpps_count > icmp6errppslim &&
(random() % (icmp6errpps_count - icmp6errppslim)) != 0) {
/* The packet is subject to rate limit */
ret++;
}
}
return ret;
}
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