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freebsd-skq/sys/netinet6/icmp6.c
Bjoern A. Zeeb 6675bee81a In icmp6_rip6_input(), once we have a lock, make sure the inp is 
not freed.  This can happen since the list traversal and locking
was converted to epoch(9).  If the inp is marked "freed", skip it.

This prevents a NULL pointer deref panic in ip6_savecontrol_v4()
trying to access the socket hanging off the inp, which was gone
by the time we got there.

Reported by:	andrew
Tested by:	andrew
Approved by:	re (gjb)
2018-09-20 15:45:53 +00:00

2824 lines
72 KiB
C
Raw Blame History

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* 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.
*
* $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $
*/
/*-
* 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#define MBUF_PRIVATE /* XXXRW: Optimisation tries to avoid M_EXT mbufs */
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/domain.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/signalvar.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sx.h>
#include <sys/syslog.h>
#include <sys/systm.h>
#include <sys/time.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_dl.h>
#include <net/if_llatbl.h>
#include <net/if_types.h>
#include <net/route.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#include <netinet/tcp_var.h>
#include <netinet6/in6_fib.h>
#include <netinet6/in6_ifattach.h>
#include <netinet6/in6_pcb.h>
#include <netinet6/ip6protosw.h>
#include <netinet6/ip6_var.h>
#include <netinet6/scope6_var.h>
#include <netinet6/mld6_var.h>
#include <netinet6/nd6.h>
#include <netinet6/send.h>
extern struct domain inet6domain;
VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat);
VNET_PCPUSTAT_SYSINIT(icmp6stat);
#ifdef VIMAGE
VNET_PCPUSTAT_SYSUNINIT(icmp6stat);
#endif /* VIMAGE */
VNET_DECLARE(struct inpcbinfo, ripcbinfo);
VNET_DECLARE(struct inpcbhead, ripcb);
VNET_DECLARE(int, icmp6errppslim);
VNET_DEFINE_STATIC(int, icmp6errpps_count) = 0;
VNET_DEFINE_STATIC(struct timeval, icmp6errppslim_last);
VNET_DECLARE(int, icmp6_nodeinfo);
#define V_ripcbinfo VNET(ripcbinfo)
#define V_ripcb VNET(ripcb)
#define V_icmp6errppslim VNET(icmp6errppslim)
#define V_icmp6errpps_count VNET(icmp6errpps_count)
#define V_icmp6errppslim_last VNET(icmp6errppslim_last)
#define V_icmp6_nodeinfo VNET(icmp6_nodeinfo)
static void icmp6_errcount(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 *, int, int);
static int ni6_dnsmatch(const char *, int, const char *, int);
static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *,
struct ifnet **, struct in6_addr *);
static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
struct ifnet *, int);
static int icmp6_notify_error(struct mbuf **, int, int, int);
/*
* Kernel module interface for updating icmp6stat. The argument is an index
* into icmp6stat treated as an array of u_quad_t. While this encodes the
* general layout of icmp6stat into the caller, it doesn't encode its
* location, so that future changes to add, for example, per-CPU stats
* support won't cause binary compatibility problems for kernel modules.
*/
void
kmod_icmp6stat_inc(int statnum)
{
counter_u64_add(VNET(icmp6stat)[statnum], 1);
}
static void
icmp6_errcount(int type, int code)
{
switch (type) {
case ICMP6_DST_UNREACH:
switch (code) {
case ICMP6_DST_UNREACH_NOROUTE:
ICMP6STAT_INC(icp6s_odst_unreach_noroute);
return;
case ICMP6_DST_UNREACH_ADMIN:
ICMP6STAT_INC(icp6s_odst_unreach_admin);
return;
case ICMP6_DST_UNREACH_BEYONDSCOPE:
ICMP6STAT_INC(icp6s_odst_unreach_beyondscope);
return;
case ICMP6_DST_UNREACH_ADDR:
ICMP6STAT_INC(icp6s_odst_unreach_addr);
return;
case ICMP6_DST_UNREACH_NOPORT:
ICMP6STAT_INC(icp6s_odst_unreach_noport);
return;
}
break;
case ICMP6_PACKET_TOO_BIG:
ICMP6STAT_INC(icp6s_opacket_too_big);
return;
case ICMP6_TIME_EXCEEDED:
switch (code) {
case ICMP6_TIME_EXCEED_TRANSIT:
ICMP6STAT_INC(icp6s_otime_exceed_transit);
return;
case ICMP6_TIME_EXCEED_REASSEMBLY:
ICMP6STAT_INC(icp6s_otime_exceed_reassembly);
return;
}
break;
case ICMP6_PARAM_PROB:
switch (code) {
case ICMP6_PARAMPROB_HEADER:
ICMP6STAT_INC(icp6s_oparamprob_header);
return;
case ICMP6_PARAMPROB_NEXTHEADER:
ICMP6STAT_INC(icp6s_oparamprob_nextheader);
return;
case ICMP6_PARAMPROB_OPTION:
ICMP6STAT_INC(icp6s_oparamprob_option);
return;
}
break;
case ND_REDIRECT:
ICMP6STAT_INC(icp6s_oredirect);
return;
}
ICMP6STAT_INC(icp6s_ounknown);
}
/*
* 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), );
#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)
{
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);
#ifdef M_DECRYPTED /*not openbsd*/
if (m->m_flags & M_DECRYPTED) {
ICMP6STAT_INC(icp6s_canterror);
goto freeit;
}
#endif
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
#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 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;
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
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_INC(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_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_NOWAIT); /* FIB is also copied over. */
if (m == NULL) {
nd6log((LOG_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 = type;
icmp6->icmp6_code = code;
icmp6->icmp6_pptr = htonl((u_int32_t)param);
ICMP6STAT_INC(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)
{
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;
char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
int ip6len, error;
ifp = m->m_pkthdr.rcvif;
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
/* m might change if M_LOOP. So, call mtod after this */
#endif
/*
* Locate icmp6 structure in mbuf, and check
* that not corrupted and of at least minimum length
*/
ip6 = mtod(m, struct ip6_hdr *);
ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
if (icmp6len < sizeof(struct icmp6_hdr)) {
ICMP6STAT_INC(icp6s_tooshort);
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;
inm = in6m_lookup(ifp, &ip6->ip6_dst);
if (inm == NULL) {
IP6STAT_INC(ip6s_notmember);
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
goto freeit;
}
}
/*
* calculate the checksum
*/
#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_INC(icp6s_tooshort);
return IPPROTO_DONE;
}
#endif
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,
ip6_sprintf(ip6bufs, &ip6->ip6_src)));
ICMP6STAT_INC(icp6s_checksum);
goto freeit;
}
ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]);
icmp6_ifstat_inc(ifp, ifs6_in_msg);
if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
icmp6_ifstat_inc(ifp, ifs6_in_error);
switch (icmp6->icmp6_type) {
case ICMP6_DST_UNREACH:
icmp6_ifstat_inc(ifp, 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(ifp, ifs6_in_adminprohib);
code = PRC_UNREACH_ADMIN_PROHIB;
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;
break;
case ICMP6_PACKET_TOO_BIG:
icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);
/* validation is made in icmp6_mtudisc_update */
code = PRC_MSGSIZE;
/*
* Updating the path MTU will be done after examining
* intermediate extension headers.
*/
goto deliver;
break;
case ICMP6_TIME_EXCEEDED:
icmp6_ifstat_inc(ifp, 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;
break;
case ICMP6_PARAM_PROB:
icmp6_ifstat_inc(ifp, 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;
break;
case ICMP6_ECHO_REQUEST:
icmp6_ifstat_inc(ifp, ifs6_in_echo);
if (code != 0)
goto badcode;
if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
/* Give up remote */
break;
}
if (!M_WRITABLE(n)
|| n->m_len < off + sizeof(struct icmp6_hdr)) {
struct mbuf *n0 = n;
int n0len;
CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN);
n = m_gethdr(M_NOWAIT, n0->m_type);
if (n == NULL) {
/* Give up remote */
m_freem(n0);
break;
}
m_move_pkthdr(n, n0); /* FIB copied. */
n0len = n0->m_pkthdr.len; /* save for use below */
/*
* 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);
/* new mbuf contains only ipv6+icmpv6 headers */
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));
/* recalculate complete packet size */
n->m_pkthdr.len = n0len + (noff - off);
n->m_next = n0;
} else {
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]);
icmp6_reflect(n, noff);
}
break;
case ICMP6_ECHO_REPLY:
icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
if (code != 0)
goto badcode;
break;
case MLD_LISTENER_QUERY:
case MLD_LISTENER_REPORT:
case MLD_LISTENER_DONE:
case MLDV2_LISTENER_REPORT:
/*
* Drop MLD traffic which is not link-local, has a hop limit
* of greater than 1 hop, or which does not have the
* IPv6 HBH Router Alert option.
* As IPv6 HBH options are stripped in ip6_input() we must
* check an mbuf header flag.
* XXX Should we also sanity check that these messages
* were directed to a link-local multicast prefix?
*/
if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0)
goto freeit;
if (mld_input(m, off, icmp6len) != 0)
return (IPPROTO_DONE);
/* m stays. */
break;
case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */
{
enum { WRU, FQDN } mode;
if (!V_icmp6_nodeinfo)
break;
if (icmp6len == sizeof(struct icmp6_hdr) + 4)
mode = WRU;
else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
mode = FQDN;
else
goto badlen;
if (mode == FQDN) {
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
IPPROTO_DONE);
#endif
n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
if (n)
n = ni6_input(n, off);
/* XXX meaningless if n == NULL */
noff = sizeof(struct ip6_hdr);
} else {
struct prison *pr;
u_char *p;
int maxhlen, hlen;
/*
* XXX: this combination of flags is pointless,
* but should we keep this for compatibility?
*/
if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK |
ICMP6_NODEINFO_TMPADDROK)) !=
(ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK))
break;
if (code != 0)
goto badcode;
CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN);
n = m_gethdr(M_NOWAIT, m->m_type);
if (n == NULL) {
/* Give up remote */
break;
}
if (!m_dup_pkthdr(n, m, M_NOWAIT)) {
/*
* Previous code did a blind M_COPY_PKTHDR
* and said "just for rcvif". If true, then
* we could tolerate the dup failing (due to
* the deep copy of the tag chain). For now
* be conservative and just fail.
*/
m_free(n);
n = NULL;
break;
}
maxhlen = M_TRAILINGSPACE(n) -
(sizeof(*nip6) + sizeof(*nicmp6) + 4);
pr = curthread->td_ucred->cr_prison;
mtx_lock(&pr->pr_mtx);
hlen = strlen(pr->pr_hostname);
if (maxhlen > hlen)
maxhlen = hlen;
/*
* 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));
p = (u_char *)(nicmp6 + 1);
bzero(p, 4);
/* meaningless TTL */
bcopy(pr->pr_hostname, p + 4, maxhlen);
mtx_unlock(&pr->pr_mtx);
noff = sizeof(struct ip6_hdr);
n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
sizeof(struct icmp6_hdr) + 4 + maxhlen;
nicmp6->icmp6_type = ICMP6_WRUREPLY;
nicmp6->icmp6_code = 0;
}
if (n) {
ICMP6STAT_INC(icp6s_reflect);
ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
icmp6_reflect(n, noff);
}
break;
}
case ICMP6_WRUREPLY:
if (code != 0)
goto badcode;
break;
case ND_ROUTER_SOLICIT:
icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
if (code != 0)
goto badcode;
if (icmp6len < sizeof(struct nd_router_solicit))
goto badlen;
if (send_sendso_input_hook != NULL) {
IP6_EXTHDR_CHECK(m, off, icmp6len, IPPROTO_DONE);
error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
if (error == 0) {
m = NULL;
goto freeit;
}
}
n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
nd6_rs_input(m, off, icmp6len);
m = n;
if (m == NULL)
goto freeit;
break;
case ND_ROUTER_ADVERT:
icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
if (code != 0)
goto badcode;
if (icmp6len < sizeof(struct nd_router_advert))
goto badlen;
if (send_sendso_input_hook != NULL) {
error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
if (error == 0) {
m = NULL;
goto freeit;
}
}
n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
nd6_ra_input(m, off, icmp6len);
m = n;
if (m == NULL)
goto freeit;
break;
case ND_NEIGHBOR_SOLICIT:
icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
if (code != 0)
goto badcode;
if (icmp6len < sizeof(struct nd_neighbor_solicit))
goto badlen;
if (send_sendso_input_hook != NULL) {
error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
if (error == 0) {
m = NULL;
goto freeit;
}
}
n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
nd6_ns_input(m, off, icmp6len);
m = n;
if (m == NULL)
goto freeit;
break;
case ND_NEIGHBOR_ADVERT:
icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
if (code != 0)
goto badcode;
if (icmp6len < sizeof(struct nd_neighbor_advert))
goto badlen;
if (send_sendso_input_hook != NULL) {
error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
if (error == 0) {
m = NULL;
goto freeit;
}
}
n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
nd6_na_input(m, off, icmp6len);
m = n;
if (m == NULL)
goto freeit;
break;
case ND_REDIRECT:
icmp6_ifstat_inc(ifp, ifs6_in_redirect);
if (code != 0)
goto badcode;
if (icmp6len < sizeof(struct nd_redirect))
goto badlen;
if (send_sendso_input_hook != NULL) {
error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
if (error == 0) {
m = NULL;
goto freeit;
}
}
n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
icmp6_redirect_input(m, off);
m = n;
if (m == NULL)
goto freeit;
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=%d)\n",
icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
ip6_sprintf(ip6bufd, &ip6->ip6_dst),
ifp ? ifp->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 */
break;
}
deliver:
if (icmp6_notify_error(&m, off, icmp6len, code) != 0) {
/* In this case, m should've been freed. */
return (IPPROTO_DONE);
}
break;
badcode:
ICMP6STAT_INC(icp6s_badcode);
break;
badlen:
ICMP6STAT_INC(icp6s_badlen);
break;
}
/* deliver the packet to appropriate sockets */
icmp6_rip6_input(&m, *offp);
return IPPROTO_DONE;
freeit:
m_freem(m);
return IPPROTO_DONE;
}
static int
icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
{
struct mbuf *m = *mp;
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;
}
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off,
sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -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_INC(icp6s_tooshort);
return (-1);
}
#endif
eip6 = (struct ip6_hdr *)(icmp6 + 1);
/* Detect the upper level protocol */
{
void (*ctlfunc)(int, struct sockaddr *, 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:
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, 0,
eoff + sizeof(struct ip6_ext), -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_INC(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), -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_INC(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, -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_INC(icp6s_tooshort);
return (-1);
}
#endif
/* 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:
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, 0, eoff +
sizeof(struct ip6_frag), -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_INC(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_INC(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);
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;
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);
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 (icmp6type == ICMP6_PACKET_TOO_BIG) {
notifymtu = ntohl(icmp6->icmp6_mtu);
ip6cp.ip6c_cmdarg = (void *)&notifymtu;
icmp6_mtudisc_update(&ip6cp, 1); /*XXX*/
}
ctlfunc = (void (*)(int, struct sockaddr *, void *))
(inet6sw[ip6_protox[nxt]].pr_ctlinput);
if (ctlfunc) {
(void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
&ip6cp);
}
}
*mp = m;
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 in_conninfo inc;
#if 0
/*
* RFC2460 section 5, last paragraph.
* even though minimum link MTU for IPv6 is IPV6_MMTU,
* we may see ICMPv6 too big with mtu < IPV6_MMTU
* due to packet translator in the middle.
* see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
* special handling.
*/
if (mtu < IPV6_MMTU)
return;
#endif
/*
* 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;
/*
* In case the suggested mtu is less than IPV6_MMTU, we
* only need to remember that it was for above mentioned
* "alwaysfrag" case.
* Try to be as close to the spec as possible.
*/
if (mtu < IPV6_MMTU)
mtu = IPV6_MMTU - 8;
bzero(&inc, sizeof(inc));
inc.inc_fibnum = M_GETFIB(m);
inc.inc_flags |= INC_ISIPV6;
inc.inc6_faddr = *dst;
if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
return;
if (mtu < tcp_maxmtu6(&inc, NULL)) {
tcp_hc_updatemtu(&inc, mtu);
ICMP6STAT_INC(icp6s_pmtuchg);
}
}
/*
* 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)
*/
static struct mbuf *
ni6_input(struct mbuf *m, int off)
{
struct icmp6_nodeinfo *ni6, *nni6;
struct mbuf *n = NULL;
struct prison *pr;
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 in6_addr in6_subj; /* subject address */
struct ip6_hdr *ip6;
int oldfqdn = 0; /* if 1, return pascal string (03 draft) */
char *subj = NULL;
struct in6_ifaddr *ia6 = 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 ((V_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))
goto bad;
/* else it's a link-local multicast, fine */
} else { /* unicast or anycast */
ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */);
if (ia6 == NULL)
goto bad; /* XXX impossible */
if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
!(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
ifa_free(&ia6->ia_ifa);
nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
"a temporary address in %s:%d",
__FILE__, __LINE__));
goto bad;
}
ifa_free(&ia6->ia_ifa);
}
/* 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;
/* 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)&in6_subj);
if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
goto bad;
subj = (char *)&in6_subj;
if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
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.
*/
pr = curthread->td_ucred->cr_prison;
mtx_lock(&pr->pr_mtx);
n = ni6_nametodns(pr->pr_hostname,
strlen(pr->pr_hostname), 0);
mtx_unlock(&pr->pr_mtx);
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 ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
goto bad;
break;
case NI_QTYPE_NODEADDR:
case NI_QTYPE_IPV4ADDR:
if ((V_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, m, &ifp, (struct in6_addr *)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. */
if (replylen > MCLBYTES) {
/*
* XXX: should we try to allocate more? But MCLBYTES
* is probably much larger than IPV6_MMTU...
*/
goto bad;
}
if (replylen > MHLEN)
n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR);
else
n = m_gethdr(M_NOWAIT, m->m_type);
if (n == NULL) {
m_freem(m);
return (NULL);
}
m_move_pkthdr(n, m); /* just for recvif and FIB */
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 hostname?
*/
pr = curthread->td_ucred->cr_prison;
mtx_lock(&pr->pr_mtx);
n->m_next = ni6_nametodns(pr->pr_hostname,
strlen(pr->pr_hostname), oldfqdn);
mtx_unlock(&pr->pr_mtx);
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 = 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);
return (n);
bad:
m_freem(m);
if (n)
m_freem(n);
return (NULL);
}
/*
* 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.
*
* old - return pascal string if non-zero
*/
static struct mbuf *
ni6_nametodns(const char *name, int namelen, int old)
{
struct mbuf *m;
char *cp, *ep;
const char *p, *q;
int i, len, nterm;
if (old)
len = namelen + 1;
else
len = MCLBYTES;
/* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */
if (len > MLEN)
m = m_getcl(M_NOWAIT, MT_DATA, 0);
else
m = m_get(M_NOWAIT, MT_DATA);
if (m == NULL)
goto fail;
if (old) {
m->m_len = len;
*mtod(m, 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++ = 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 = 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 mbuf *m, struct ifnet **ifpp,
struct in6_addr *subj)
{
struct ifnet *ifp;
struct in6_ifaddr *ifa6;
struct ifaddr *ifa;
int addrs = 0, addrsofif, iffound = 0;
int niflags = ni6->ni_flags;
if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
switch (ni6->ni_code) {
case ICMP6_NI_SUBJ_IPV6:
if (subj == NULL) /* must be impossible... */
return (0);
break;
default:
/*
* XXX: we only support IPv6 subject address for
* this Qtype.
*/
return (0);
}
}
IFNET_RLOCK_NOSLEEP();
CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
addrsofif = 0;
IF_ADDR_RLOCK(ifp);
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family != AF_INET6)
continue;
ifa6 = (struct in6_ifaddr *)ifa;
if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
IN6_ARE_ADDR_EQUAL(subj, &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)
continue;
break;
case IPV6_ADDR_SCOPE_SITELOCAL:
if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
continue;
break;
case IPV6_ADDR_SCOPE_GLOBAL:
if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
continue;
break;
default:
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)
continue; /* we need only unicast addresses */
if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
continue;
}
addrsofif++; /* count the address */
}
IF_ADDR_RUNLOCK(ifp);
if (iffound) {
*ifpp = ifp;
IFNET_RUNLOCK_NOSLEEP();
return (addrsofif);
}
addrs += addrsofif;
}
IFNET_RUNLOCK_NOSLEEP();
return (addrs);
}
static int
ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
struct ifnet *ifp0, int resid)
{
struct ifnet *ifp;
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;
if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
return (0); /* needless to copy */
IFNET_RLOCK_NOSLEEP();
ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet);
again:
for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) {
IF_ADDR_RLOCK(ifp);
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family != AF_INET6)
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;
continue;
} else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
allow_deprecated != 0)
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)
continue;
break;
case IPV6_ADDR_SCOPE_SITELOCAL:
if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
continue;
break;
case IPV6_ADDR_SCOPE_GLOBAL:
if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
continue;
break;
default:
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)
continue;
if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
continue;
}
/* now we can copy the address */
if (resid < sizeof(struct in6_addr) +
sizeof(u_int32_t)) {
IF_ADDR_RUNLOCK(ifp);
/*
* We give up much more copy.
* Set the truncate flag and return.
*/
nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
IFNET_RUNLOCK_NOSLEEP();
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.
*/
if (ifa6->ia6_lifetime.ia6t_expire == 0)
ltime = ND6_INFINITE_LIFETIME;
else {
if (ifa6->ia6_lifetime.ia6t_expire >
time_uptime)
ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime);
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));
in6_clearscope((struct in6_addr *)cp); /* XXX */
cp += sizeof(struct in6_addr);
resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
}
IF_ADDR_RUNLOCK(ifp);
if (ifp0) /* we need search only on the specified IF */
break;
}
if (allow_deprecated == 0 && ifp_dep != NULL) {
ifp = ifp_dep;
allow_deprecated = 1;
goto again;
}
IFNET_RUNLOCK_NOSLEEP();
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 inpcb *in6p;
struct inpcb *last = NULL;
struct sockaddr_in6 fromsa;
struct icmp6_hdr *icmp6;
struct epoch_tracker et;
struct mbuf *opts = NULL;
#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(&fromsa, sizeof(fromsa));
fromsa.sin6_family = AF_INET6;
fromsa.sin6_len = sizeof(struct sockaddr_in6);
fromsa.sin6_addr = ip6->ip6_src;
if (sa6_recoverscope(&fromsa)) {
m_freem(m);
return (IPPROTO_DONE);
}
INP_INFO_RLOCK_ET(&V_ripcbinfo, et);
CK_LIST_FOREACH(in6p, &V_ripcb, inp_list) {
if ((in6p->inp_vflag & INP_IPV6) == 0)
continue;
if (in6p->inp_ip_p != 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;
INP_RLOCK(in6p);
if (__predict_false(in6p->inp_flags2 & INP_FREED)) {
INP_RUNLOCK(in6p);
continue;
}
if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
in6p->in6p_icmp6filt)) {
INP_RUNLOCK(in6p);
continue;
}
if (last != NULL) {
struct mbuf *n = NULL;
/*
* Recent network drivers tend to allocate a single
* mbuf cluster, rather than to make a couple of
* mbufs without clusters. Also, since the IPv6 code
* path tries to avoid m_pullup(), it is highly
* probable that we still have an mbuf cluster here
* even though the necessary length can be stored in an
* mbuf's internal buffer.
* Meanwhile, the default size of the receive socket
* buffer for raw sockets is not so large. This means
* the possibility of packet loss is relatively higher
* than before. To avoid this scenario, we copy the
* received data to a separate mbuf that does not use
* a cluster, if possible.
* XXX: it is better to copy the data after stripping
* intermediate headers.
*/
if ((m->m_flags & M_EXT) && m->m_next == NULL &&
m->m_len <= MHLEN) {
n = m_get(M_NOWAIT, m->m_type);
if (n != NULL) {
if (m_dup_pkthdr(n, m, M_NOWAIT)) {
bcopy(m->m_data, n->m_data,
m->m_len);
n->m_len = m->m_len;
} else {
m_free(n);
n = NULL;
}
}
}
if (n != NULL ||
(n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) {
if (last->inp_flags & INP_CONTROLOPTS)
ip6_savecontrol(last, n, &opts);
/* strip intermediate headers */
m_adj(n, off);
SOCKBUF_LOCK(&last->inp_socket->so_rcv);
if (sbappendaddr_locked(
&last->inp_socket->so_rcv,
(struct sockaddr *)&fromsa, n, opts)
== 0) {
/* should notify about lost packet */
m_freem(n);
if (opts) {
m_freem(opts);
}
SOCKBUF_UNLOCK(
&last->inp_socket->so_rcv);
} else
sorwakeup_locked(last->inp_socket);
opts = NULL;
}
INP_RUNLOCK(last);
}
last = in6p;
}
INP_INFO_RUNLOCK_ET(&V_ripcbinfo, et);
if (last != NULL) {
if (last->inp_flags & INP_CONTROLOPTS)
ip6_savecontrol(last, m, &opts);
/* strip intermediate headers */
m_adj(m, off);
/* avoid using mbuf clusters if possible (see above) */
if ((m->m_flags & M_EXT) && m->m_next == NULL &&
m->m_len <= MHLEN) {
struct mbuf *n;
n = m_get(M_NOWAIT, m->m_type);
if (n != NULL) {
if (m_dup_pkthdr(n, m, M_NOWAIT)) {
bcopy(m->m_data, n->m_data, m->m_len);
n->m_len = m->m_len;
m_freem(m);
m = n;
} else {
m_freem(n);
n = NULL;
}
}
}
SOCKBUF_LOCK(&last->inp_socket->so_rcv);
if (sbappendaddr_locked(&last->inp_socket->so_rcv,
(struct sockaddr *)&fromsa, m, opts) == 0) {
m_freem(m);
if (opts)
m_freem(opts);
SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
} else
sorwakeup_locked(last->inp_socket);
INP_RUNLOCK(last);
} else {
m_freem(m);
IP6STAT_DEC(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 in6_addr src6, *srcp;
struct ip6_hdr *ip6;
struct icmp6_hdr *icmp6;
struct in6_ifaddr *ia = NULL;
struct ifnet *outif = NULL;
int plen;
int type, code, hlim;
/* 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 there are extra headers between IPv6 and ICMPv6, strip
* off that header first.
*/
#ifdef DIAGNOSTIC
if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
panic("assumption failed in icmp6_reflect");
#endif
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 = m_pullup(m, l)) == 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 = m_pullup(m, l)) == NULL)
return;
}
}
plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
ip6 = mtod(m, 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. */
hlim = 0;
srcp = 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.
*/
if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */);
if (ia != NULL && !(ia->ia6_flags &
(IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
src6 = ia->ia_addr.sin6_addr;
srcp = &src6;
if (m->m_pkthdr.rcvif != NULL) {
/* XXX: This may not be the outgoing interface */
hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
} else
hlim = V_ip6_defhlim;
}
if (ia != NULL)
ifa_free(&ia->ia_ifa);
}
if (srcp == NULL) {
int error;
struct in6_addr dst6;
uint32_t scopeid;
/*
* 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.
*/
in6_splitscope(&ip6->ip6_src, &dst6, &scopeid);
error = in6_selectsrc_addr(M_GETFIB(m), &dst6,
scopeid, NULL, &src6, &hlim);
if (error) {
char ip6buf[INET6_ADDRSTRLEN];
nd6log((LOG_DEBUG,
"icmp6_reflect: source can't be determined: "
"dst=%s, error=%d\n",
ip6_sprintf(ip6buf, &ip6->ip6_dst), error));
goto bad;
}
srcp = &src6;
}
/*
* ip6_input() drops a packet if its src is multicast.
* So, the src is never multicast.
*/
ip6->ip6_dst = ip6->ip6_src;
ip6->ip6_src = *srcp;
ip6->ip6_flow = 0;
ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
ip6->ip6_vfc |= IPV6_VERSION;
ip6->ip6_nxt = IPPROTO_ICMPV6;
ip6->ip6_hlim = hlim;
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);
m->m_pkthdr.rcvif = NULL;
ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
if (outif)
icmp6_ifoutstat_inc(outif, type, code);
return;
bad:
m_freem(m);
return;
}
void
icmp6_fasttimo(void)
{
mld_fasttimo();
}
void
icmp6_slowtimo(void)
{
mld_slowtimo();
}
static const char *
icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
struct in6_addr *tgt6)
{
static char buf[1024];
char ip6bufs[INET6_ADDRSTRLEN];
char ip6bufd[INET6_ADDRSTRLEN];
char ip6buft[INET6_ADDRSTRLEN];
snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
ip6_sprintf(ip6buft, tgt6));
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;
int is_router;
int is_onlink;
struct in6_addr src6 = ip6->ip6_src;
struct in6_addr redtgt6;
struct in6_addr reddst6;
union nd_opts ndopts;
char ip6buf[INET6_ADDRSTRLEN];
M_ASSERTPKTHDR(m);
KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__));
ifp = m->m_pkthdr.rcvif;
/* XXX if we are router, we don't update route by icmp6 redirect */
if (V_ip6_forwarding)
goto freeit;
if (!V_icmp6_rediraccept)
goto freeit;
/* RFC 6980: Nodes MUST silently ignore fragments */
if(m->m_flags & M_FRAGMENTED)
goto freeit;
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, icmp6len,);
nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
#else
IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
if (nd_rd == NULL) {
ICMP6STAT_INC(icp6s_tooshort);
return;
}
#endif
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((LOG_ERR,
"ICMP6 redirect sent from %s rejected; "
"must be from linklocal\n",
ip6_sprintf(ip6buf, &src6)));
goto bad;
}
if (ip6->ip6_hlim != 255) {
nd6log((LOG_ERR,
"ICMP6 redirect sent from %s rejected; "
"hlim=%d (must be 255)\n",
ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
goto bad;
}
{
/* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
struct nhop6_basic nh6;
struct in6_addr kdst;
uint32_t scopeid;
in6_splitscope(&reddst6, &kdst, &scopeid);
if (fib6_lookup_nh_basic(ifp->if_fib, &kdst, scopeid, 0, 0,&nh6)==0){
if ((nh6.nh_flags & NHF_GATEWAY) == 0) {
nd6log((LOG_ERR,
"ICMP6 redirect rejected; no route "
"with inet6 gateway found for redirect dst: %s\n",
icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
goto bad;
}
/*
* Embed scope zone id into next hop address, since
* fib6_lookup_nh_basic() returns address without embedded
* scope zone id.
*/
if (in6_setscope(&nh6.nh_addr, m->m_pkthdr.rcvif, NULL))
goto freeit;
if (IN6_ARE_ADDR_EQUAL(&src6, &nh6.nh_addr) == 0) {
nd6log((LOG_ERR,
"ICMP6 redirect rejected; "
"not equal to gw-for-src=%s (must be same): "
"%s\n",
ip6_sprintf(ip6buf, &nh6.nh_addr),
icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
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;
}
}
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;
}
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;
}
icmp6len -= sizeof(*nd_rd);
nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
if (nd6_options(&ndopts) < 0) {
nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n",
__func__, 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, "%s: lladdrlen mismatch for %s "
"(if %d, icmp6 packet %d): %s\n",
__func__, ip6_sprintf(ip6buf, &redtgt6),
ifp->if_addrlen, lladdrlen - 2,
icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
goto bad;
}
/* Validation passed. */
/* RFC 2461 8.3 */
nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
/*
* Install a gateway route in the better-router case or an interface
* route in the on-link-destination case.
*/
{
struct sockaddr_in6 sdst;
struct sockaddr_in6 sgw;
struct sockaddr_in6 ssrc;
struct sockaddr *gw;
int rt_flags;
u_int fibnum;
bzero(&sdst, sizeof(sdst));
bzero(&ssrc, sizeof(ssrc));
sdst.sin6_family = ssrc.sin6_family = AF_INET6;
sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6);
bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
rt_flags = RTF_HOST;
if (is_router) {
bzero(&sgw, sizeof(sgw));
sgw.sin6_family = AF_INET6;
sgw.sin6_len = sizeof(struct sockaddr_in6);
bcopy(&redtgt6, &sgw.sin6_addr,
sizeof(struct in6_addr));
gw = (struct sockaddr *)&sgw;
rt_flags |= RTF_GATEWAY;
} else
gw = ifp->if_addr->ifa_addr;
for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
in6_rtredirect((struct sockaddr *)&sdst, gw,
(struct sockaddr *)NULL, rt_flags,
(struct sockaddr *)&ssrc, fibnum);
}
/* 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);
}
freeit:
m_freem(m);
return;
bad:
ICMP6STAT_INC(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 m_tag *mtag;
struct ip6_hdr *ip6; /* m as struct ip6_hdr */
struct nd_redirect *nd_rd;
struct llentry *ln = NULL;
size_t maxlen;
u_char *p;
struct ifnet *outif = NULL;
struct sockaddr_in6 src_sa;
icmp6_errcount(ND_REDIRECT, 0);
/* if we are not router, we don't send icmp6 redirect */
if (!V_ip6_forwarding)
goto fail;
/* sanity check */
if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
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;
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
m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
if (m == NULL)
goto fail;
M_SETFIB(m, rt->rt_fibnum);
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;
ifp_ll6 = &ia->ia_addr.sin6_addr;
/* XXXRW: reference released prematurely. */
ifa_free(&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 *)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 = 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 (!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));
}
p = (u_char *)(nd_rd + 1);
if (!router_ll6)
goto nolladdropt;
{
/* target lladdr option */
int len;
struct nd_opt_hdr *nd_opt;
char *lladdr;
IF_AFDATA_RLOCK(ifp);
ln = nd6_lookup(router_ll6, 0, ifp);
IF_AFDATA_RUNLOCK(ifp);
if (ln == NULL)
goto nolladdropt;
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;
if (ln->la_flags & LLE_VALID) {
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(ln->ll_addr, lladdr, ifp->if_addrlen);
p += len;
}
}
nolladdropt:
if (ln != NULL)
LLE_RUNLOCK(ln);
m->m_pkthdr.len = m->m_len = 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 = 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", __FILE__,
__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 = len >> 3;
p += sizeof(*nd_opt_rh);
m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
/* connect m0 to m */
m_tag_delete_chain(m0, NULL);
m0->m_flags &= ~M_PKTHDR;
m->m_next = m0;
m->m_pkthdr.len = m->m_len + m0->m_len;
m0 = NULL;
}
noredhdropt:;
if (m0) {
m_freem(m0);
m0 = NULL;
}
/* 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(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));
if (send_sendso_input_hook != NULL) {
mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short),
M_NOWAIT);
if (mtag == NULL)
goto fail;
*(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type;
m_tag_prepend(m, mtag);
}
/* send the packet to outside... */
ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
if (outif) {
icmp6_ifstat_inc(outif, ifs6_out_msg);
icmp6_ifstat_inc(outif, ifs6_out_redirect);
}
ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
return;
fail:
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;
int 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 ic6f;
if (optlen != sizeof(ic6f)) {
error = EMSGSIZE;
break;
}
error = sooptcopyin(sopt, &ic6f, optlen, optlen);
if (error == 0) {
INP_WLOCK(inp);
*inp->in6p_icmp6filt = ic6f;
INP_WUNLOCK(inp);
}
break;
}
default:
error = ENOPROTOOPT;
break;
}
break;
case PRCO_GETOPT:
switch (optname) {
case ICMP6_FILTER:
{
struct icmp6_filter ic6f;
INP_RLOCK(inp);
ic6f = *inp->in6p_icmp6filt;
INP_RUNLOCK(inp);
error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
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
*/
static int
icmp6_ratelimit(const struct in6_addr *dst, const int type,
const int code)
{
int ret;
ret = 0; /* okay to send */
/* PPS limit */
if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
V_icmp6errppslim)) {
/* The packet is subject to rate limit */
ret++;
}
return ret;
}
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