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freebsd-skq/sys/netinet6/icmp6.c
imp 7e6cabd06e Renumber copyright clause 4 
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by:	Jan Schaumann <jschauma@stevens.edu>
Pull Request:	https://github.com/freebsd/freebsd/pull/96
2017-02-28 23:42:47 +00:00

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/*-
* 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);
static VNET_DEFINE(int, icmp6errpps_count) = 0;
static VNET_DEFINE(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);
/*
* 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).
*/
m->m_pkthdr.rcvif = NULL;
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 {
nip6 = mtod(n, struct ip6_hdr *);
IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
sizeof(*nicmp6));
noff = off;
}
nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
nicmp6->icmp6_code = 0;
if (n) {
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;
}
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();
TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
addrsofif = 0;
IF_ADDR_RLOCK(ifp);
TAILQ_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 : TAILQ_FIRST(&V_ifnet);
again:
for (; ifp; ifp = TAILQ_NEXT(ifp, if_link)) {
IF_ADDR_RLOCK(ifp);
TAILQ_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 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(&V_ripcbinfo);
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 (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(&V_ripcbinfo);
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(RT_DEFAULT_FIB, &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);
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;
#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(RT_DEFAULT_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;
}
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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