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freebsd-dev/sys/netinet6/ip6_input.c
Bjoern A. Zeeb ae14505058 MFp4 bz_ipv6_fast: 
Factor out Hop-By-Hop option processing.  It's still not heavily used,
  it reduces the footprint of ip6_input() and makes ip6_input() more
  readable.

  Sponsored by:	The FreeBSD Foundation
  Sponsored by:	iXsystems

Reviewed by:	gnn (as part of the whole)
MFC After:	3 days
2012-05-25 02:58:21 +00:00

1843 lines
48 KiB
C
Raw Blame History

/*-
* 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: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei 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.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)ip_input.c 8.2 (Berkeley) 1/4/94
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipfw.h"
#include "opt_ipsec.h"
#include "opt_route.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/proc.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <net/netisr.h>
#include <net/pfil.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/ip_var.h>
#include <netinet/in_systm.h>
#include <net/if_llatbl.h>
#ifdef INET
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#endif /* INET */
#include <netinet/ip6.h>
#include <netinet6/in6_var.h>
#include <netinet6/ip6_var.h>
#include <netinet/in_pcb.h>
#include <netinet/icmp6.h>
#include <netinet6/scope6_var.h>
#include <netinet6/in6_ifattach.h>
#include <netinet6/nd6.h>
#ifdef IPSEC
#include <netipsec/ipsec.h>
#include <netinet6/ip6_ipsec.h>
#include <netipsec/ipsec6.h>
#endif /* IPSEC */
#include <netinet6/ip6protosw.h>
#ifdef FLOWTABLE
#include <net/flowtable.h>
VNET_DECLARE(int, ip6_output_flowtable_size);
#define V_ip6_output_flowtable_size VNET(ip6_output_flowtable_size)
#endif
extern struct domain inet6domain;
u_char ip6_protox[IPPROTO_MAX];
VNET_DEFINE(struct in6_ifaddrhead, in6_ifaddrhead);
static struct netisr_handler ip6_nh = {
.nh_name = "ip6",
.nh_handler = ip6_input,
.nh_proto = NETISR_IPV6,
.nh_policy = NETISR_POLICY_FLOW,
};
VNET_DECLARE(struct callout, in6_tmpaddrtimer_ch);
#define V_in6_tmpaddrtimer_ch VNET(in6_tmpaddrtimer_ch)
VNET_DEFINE(struct pfil_head, inet6_pfil_hook);
VNET_DEFINE(struct ip6stat, ip6stat);
struct rwlock in6_ifaddr_lock;
RW_SYSINIT(in6_ifaddr_lock, &in6_ifaddr_lock, "in6_ifaddr_lock");
static void ip6_init2(void *);
static struct ip6aux *ip6_setdstifaddr(struct mbuf *, struct in6_ifaddr *);
static struct ip6aux *ip6_addaux(struct mbuf *);
static struct ip6aux *ip6_findaux(struct mbuf *m);
static void ip6_delaux (struct mbuf *);
static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *);
#ifdef PULLDOWN_TEST
static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int);
#endif
/*
* IP6 initialization: fill in IP6 protocol switch table.
* All protocols not implemented in kernel go to raw IP6 protocol handler.
*/
void
ip6_init(void)
{
struct ip6protosw *pr;
int i;
TUNABLE_INT_FETCH("net.inet6.ip6.auto_linklocal",
&V_ip6_auto_linklocal);
TUNABLE_INT_FETCH("net.inet6.ip6.accept_rtadv", &V_ip6_accept_rtadv);
TUNABLE_INT_FETCH("net.inet6.ip6.no_radr", &V_ip6_no_radr);
TAILQ_INIT(&V_in6_ifaddrhead);
/* Initialize packet filter hooks. */
V_inet6_pfil_hook.ph_type = PFIL_TYPE_AF;
V_inet6_pfil_hook.ph_af = AF_INET6;
if ((i = pfil_head_register(&V_inet6_pfil_hook)) != 0)
printf("%s: WARNING: unable to register pfil hook, "
"error %d\n", __func__, i);
scope6_init();
addrsel_policy_init();
nd6_init();
frag6_init();
#ifdef FLOWTABLE
if (TUNABLE_INT_FETCH("net.inet6.ip6.output_flowtable_size",
&V_ip6_output_flowtable_size)) {
if (V_ip6_output_flowtable_size < 256)
V_ip6_output_flowtable_size = 256;
if (!powerof2(V_ip6_output_flowtable_size)) {
printf("flowtable must be power of 2 size\n");
V_ip6_output_flowtable_size = 2048;
}
} else {
/*
* round up to the next power of 2
*/
V_ip6_output_flowtable_size = 1 << fls((1024 + maxusers * 64)-1);
}
V_ip6_ft = flowtable_alloc("ipv6", V_ip6_output_flowtable_size, FL_IPV6|FL_PCPU);
#endif
V_ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR;
/* Skip global initialization stuff for non-default instances. */
if (!IS_DEFAULT_VNET(curvnet))
return;
#ifdef DIAGNOSTIC
if (sizeof(struct protosw) != sizeof(struct ip6protosw))
panic("sizeof(protosw) != sizeof(ip6protosw)");
#endif
pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
if (pr == NULL)
panic("ip6_init");
/* Initialize the entire ip6_protox[] array to IPPROTO_RAW. */
for (i = 0; i < IPPROTO_MAX; i++)
ip6_protox[i] = pr - inet6sw;
/*
* Cycle through IP protocols and put them into the appropriate place
* in ip6_protox[].
*/
for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++)
if (pr->pr_domain->dom_family == PF_INET6 &&
pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
/* Be careful to only index valid IP protocols. */
if (pr->pr_protocol < IPPROTO_MAX)
ip6_protox[pr->pr_protocol] = pr - inet6sw;
}
netisr_register(&ip6_nh);
}
/*
* The protocol to be inserted into ip6_protox[] must be already registered
* in inet6sw[], either statically or through pf_proto_register().
*/
int
ip6proto_register(short ip6proto)
{
struct ip6protosw *pr;
/* Sanity checks. */
if (ip6proto <= 0 || ip6proto >= IPPROTO_MAX)
return (EPROTONOSUPPORT);
/*
* The protocol slot must not be occupied by another protocol
* already. An index pointing to IPPROTO_RAW is unused.
*/
pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
if (pr == NULL)
return (EPFNOSUPPORT);
if (ip6_protox[ip6proto] != pr - inet6sw) /* IPPROTO_RAW */
return (EEXIST);
/*
* Find the protocol position in inet6sw[] and set the index.
*/
for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) {
if (pr->pr_domain->dom_family == PF_INET6 &&
pr->pr_protocol && pr->pr_protocol == ip6proto) {
ip6_protox[pr->pr_protocol] = pr - inet6sw;
return (0);
}
}
return (EPROTONOSUPPORT);
}
int
ip6proto_unregister(short ip6proto)
{
struct ip6protosw *pr;
/* Sanity checks. */
if (ip6proto <= 0 || ip6proto >= IPPROTO_MAX)
return (EPROTONOSUPPORT);
/* Check if the protocol was indeed registered. */
pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
if (pr == NULL)
return (EPFNOSUPPORT);
if (ip6_protox[ip6proto] == pr - inet6sw) /* IPPROTO_RAW */
return (ENOENT);
/* Reset the protocol slot to IPPROTO_RAW. */
ip6_protox[ip6proto] = pr - inet6sw;
return (0);
}
#ifdef VIMAGE
void
ip6_destroy()
{
nd6_destroy();
callout_drain(&V_in6_tmpaddrtimer_ch);
}
#endif
static int
ip6_init2_vnet(const void *unused __unused)
{
/* nd6_timer_init */
callout_init(&V_nd6_timer_ch, 0);
callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet);
/* timer for regeneranation of temporary addresses randomize ID */
callout_init(&V_in6_tmpaddrtimer_ch, 0);
callout_reset(&V_in6_tmpaddrtimer_ch,
(V_ip6_temp_preferred_lifetime - V_ip6_desync_factor -
V_ip6_temp_regen_advance) * hz,
in6_tmpaddrtimer, curvnet);
return (0);
}
static void
ip6_init2(void *dummy)
{
ip6_init2_vnet(NULL);
}
/* cheat */
/* This must be after route_init(), which is now SI_ORDER_THIRD */
SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL);
static int
ip6_input_hbh(struct mbuf *m, uint32_t *plen, uint32_t *rtalert, int *off,
int *nxt, int *ours)
{
struct ip6_hdr *ip6;
struct ip6_hbh *hbh;
if (ip6_hopopts_input(plen, rtalert, &m, off)) {
#if 0 /*touches NULL pointer*/
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
#endif
goto out; /* m have already been freed */
}
/* adjust pointer */
ip6 = mtod(m, struct ip6_hdr *);
/*
* if the payload length field is 0 and the next header field
* indicates Hop-by-Hop Options header, then a Jumbo Payload
* option MUST be included.
*/
if (ip6->ip6_plen == 0 && *plen == 0) {
/*
* Note that if a valid jumbo payload option is
* contained, ip6_hopopts_input() must set a valid
* (non-zero) payload length to the variable plen.
*/
V_ip6stat.ip6s_badoptions++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
icmp6_error(m, ICMP6_PARAM_PROB,
ICMP6_PARAMPROB_HEADER,
(caddr_t)&ip6->ip6_plen - (caddr_t)ip6);
goto out;
}
#ifndef PULLDOWN_TEST
/* ip6_hopopts_input() ensures that mbuf is contiguous */
hbh = (struct ip6_hbh *)(ip6 + 1);
#else
IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
sizeof(struct ip6_hbh));
if (hbh == NULL) {
V_ip6stat.ip6s_tooshort++;
goto out;
}
#endif
*nxt = hbh->ip6h_nxt;
/*
* If we are acting as a router and the packet contains a
* router alert option, see if we know the option value.
* Currently, we only support the option value for MLD, in which
* case we should pass the packet to the multicast routing
* daemon.
*/
if (*rtalert != ~0) {
switch (*rtalert) {
case IP6OPT_RTALERT_MLD:
if (V_ip6_forwarding)
*ours = 1;
break;
default:
/*
* RFC2711 requires unrecognized values must be
* silently ignored.
*/
break;
}
}
return (0);
out:
return (1);
}
void
ip6_input(struct mbuf *m)
{
struct ip6_hdr *ip6;
int off = sizeof(struct ip6_hdr), nest;
u_int32_t plen;
u_int32_t rtalert = ~0;
int nxt, ours = 0;
struct ifnet *deliverifp = NULL, *ifp = NULL;
struct in6_addr odst;
struct route_in6 rin6;
int srcrt = 0;
struct llentry *lle = NULL;
struct sockaddr_in6 dst6, *dst;
bzero(&rin6, sizeof(struct route_in6));
#ifdef IPSEC
/*
* should the inner packet be considered authentic?
* see comment in ah4_input().
* NB: m cannot be NULL when passed to the input routine
*/
m->m_flags &= ~M_AUTHIPHDR;
m->m_flags &= ~M_AUTHIPDGM;
#endif /* IPSEC */
/*
* make sure we don't have onion peering information into m_tag.
*/
ip6_delaux(m);
if (m->m_flags & M_FASTFWD_OURS) {
/*
* Firewall changed destination to local.
*/
m->m_flags &= ~M_FASTFWD_OURS;
ours = 1;
deliverifp = m->m_pkthdr.rcvif;
ip6 = mtod(m, struct ip6_hdr *);
goto hbhcheck;
}
/*
* mbuf statistics
*/
if (m->m_flags & M_EXT) {
if (m->m_next)
V_ip6stat.ip6s_mext2m++;
else
V_ip6stat.ip6s_mext1++;
} else {
#define M2MMAX (sizeof(V_ip6stat.ip6s_m2m)/sizeof(V_ip6stat.ip6s_m2m[0]))
if (m->m_next) {
if (m->m_flags & M_LOOP) {
V_ip6stat.ip6s_m2m[V_loif->if_index]++;
} else if (m->m_pkthdr.rcvif->if_index < M2MMAX)
V_ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++;
else
V_ip6stat.ip6s_m2m[0]++;
} else
V_ip6stat.ip6s_m1++;
#undef M2MMAX
}
/* drop the packet if IPv6 operation is disabled on the IF */
if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) {
m_freem(m);
return;
}
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive);
V_ip6stat.ip6s_total++;
#ifndef PULLDOWN_TEST
/*
* L2 bridge code and some other code can return mbuf chain
* that does not conform to KAME requirement. too bad.
* XXX: fails to join if interface MTU > MCLBYTES. jumbogram?
*/
if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) {
struct mbuf *n;
MGETHDR(n, M_DONTWAIT, MT_HEADER);
if (n)
M_MOVE_PKTHDR(n, m);
if (n && n->m_pkthdr.len > MHLEN) {
MCLGET(n, M_DONTWAIT);
if ((n->m_flags & M_EXT) == 0) {
m_freem(n);
n = NULL;
}
}
if (n == NULL) {
m_freem(m);
return; /* ENOBUFS */
}
m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
n->m_len = n->m_pkthdr.len;
m_freem(m);
m = n;
}
IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */);
#endif
if (m->m_len < sizeof(struct ip6_hdr)) {
struct ifnet *inifp;
inifp = m->m_pkthdr.rcvif;
if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
V_ip6stat.ip6s_toosmall++;
in6_ifstat_inc(inifp, ifs6_in_hdrerr);
return;
}
}
ip6 = mtod(m, struct ip6_hdr *);
if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
V_ip6stat.ip6s_badvers++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
goto bad;
}
V_ip6stat.ip6s_nxthist[ip6->ip6_nxt]++;
/*
* Check against address spoofing/corruption.
*/
if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) ||
IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) {
/*
* XXX: "badscope" is not very suitable for a multicast source.
*/
V_ip6stat.ip6s_badscope++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
goto bad;
}
if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) &&
!(m->m_flags & M_LOOP)) {
/*
* In this case, the packet should come from the loopback
* interface. However, we cannot just check the if_flags,
* because ip6_mloopback() passes the "actual" interface
* as the outgoing/incoming interface.
*/
V_ip6stat.ip6s_badscope++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
goto bad;
}
#ifdef ALTQ
if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) {
/* packet is dropped by traffic conditioner */
return;
}
#endif
/*
* The following check is not documented in specs. A malicious
* party may be able to use IPv4 mapped addr to confuse tcp/udp stack
* and bypass security checks (act as if it was from 127.0.0.1 by using
* IPv6 src ::ffff:127.0.0.1). Be cautious.
*
* This check chokes if we are in an SIIT cloud. As none of BSDs
* support IPv4-less kernel compilation, we cannot support SIIT
* environment at all. So, it makes more sense for us to reject any
* malicious packets for non-SIIT environment, than try to do a
* partial support for SIIT environment.
*/
if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
V_ip6stat.ip6s_badscope++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
goto bad;
}
#if 0
/*
* Reject packets with IPv4 compatible addresses (auto tunnel).
*
* The code forbids auto tunnel relay case in RFC1933 (the check is
* stronger than RFC1933). We may want to re-enable it if mech-xx
* is revised to forbid relaying case.
*/
if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
V_ip6stat.ip6s_badscope++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
goto bad;
}
#endif
#ifdef IPSEC
/*
* Bypass packet filtering for packets previously handled by IPsec.
*/
if (ip6_ipsec_filtertunnel(m))
goto passin;
#endif /* IPSEC */
/*
* Run through list of hooks for input packets.
*
* NB: Beware of the destination address changing
* (e.g. by NAT rewriting). When this happens,
* tell ip6_forward to do the right thing.
*/
odst = ip6->ip6_dst;
/* Jump over all PFIL processing if hooks are not active. */
if (!PFIL_HOOKED(&V_inet6_pfil_hook))
goto passin;
if (pfil_run_hooks(&V_inet6_pfil_hook, &m,
m->m_pkthdr.rcvif, PFIL_IN, NULL))
return;
if (m == NULL) /* consumed by filter */
return;
ip6 = mtod(m, struct ip6_hdr *);
srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst);
#ifdef IPFIREWALL_FORWARD
if (m->m_flags & M_FASTFWD_OURS) {
m->m_flags &= ~M_FASTFWD_OURS;
ours = 1;
deliverifp = m->m_pkthdr.rcvif;
goto hbhcheck;
}
if (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL) {
/*
* Directly ship the packet on. This allows forwarding
* packets originally destined to us to some other directly
* connected host.
*/
ip6_forward(m, 1);
goto out;
}
#endif /* IPFIREWALL_FORWARD */
passin:
/*
* Disambiguate address scope zones (if there is ambiguity).
* We first make sure that the original source or destination address
* is not in our internal form for scoped addresses. Such addresses
* are not necessarily invalid spec-wise, but we cannot accept them due
* to the usage conflict.
* in6_setscope() then also checks and rejects the cases where src or
* dst are the loopback address and the receiving interface
* is not loopback.
*/
if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) {
V_ip6stat.ip6s_badscope++; /* XXX */
goto bad;
}
if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) ||
in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) {
V_ip6stat.ip6s_badscope++;
goto bad;
}
/*
* Multicast check. Assume packet is for us to avoid
* prematurely taking locks.
*/
if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
ours = 1;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast);
deliverifp = m->m_pkthdr.rcvif;
goto hbhcheck;
}
/*
* Unicast check
*/
bzero(&dst6, sizeof(dst6));
dst6.sin6_family = AF_INET6;
dst6.sin6_len = sizeof(struct sockaddr_in6);
dst6.sin6_addr = ip6->ip6_dst;
ifp = m->m_pkthdr.rcvif;
IF_AFDATA_LOCK(ifp);
lle = lla_lookup(LLTABLE6(ifp), 0,
(struct sockaddr *)&dst6);
IF_AFDATA_UNLOCK(ifp);
if ((lle != NULL) && (lle->la_flags & LLE_IFADDR)) {
struct ifaddr *ifa;
struct in6_ifaddr *ia6;
int bad;
bad = 1;
#define sa_equal(a1, a2) \
(bcmp((a1), (a2), ((a1))->sin6_len) == 0)
IF_ADDR_RLOCK(ifp);
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family != dst6.sin6_family)
continue;
if (sa_equal(&dst6, ifa->ifa_addr))
break;
}
KASSERT(ifa != NULL, ("%s: ifa not found for lle %p",
__func__, lle));
#undef sa_equal
ia6 = (struct in6_ifaddr *)ifa;
if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
/* Count the packet in the ip address stats */
ia6->ia_ifa.if_ipackets++;
ia6->ia_ifa.if_ibytes += m->m_pkthdr.len;
/*
* record address information into m_tag.
*/
(void)ip6_setdstifaddr(m, ia6);
bad = 0;
} else {
char ip6bufs[INET6_ADDRSTRLEN];
char ip6bufd[INET6_ADDRSTRLEN];
/* address is not ready, so discard the packet. */
nd6log((LOG_INFO,
"ip6_input: packet to an unready address %s->%s\n",
ip6_sprintf(ip6bufs, &ip6->ip6_src),
ip6_sprintf(ip6bufd, &ip6->ip6_dst)));
}
IF_ADDR_RUNLOCK(ifp);
LLE_RUNLOCK(lle);
if (bad)
goto bad;
else {
ours = 1;
deliverifp = ifp;
goto hbhcheck;
}
}
if (lle != NULL)
LLE_RUNLOCK(lle);
dst = &rin6.ro_dst;
dst->sin6_len = sizeof(struct sockaddr_in6);
dst->sin6_family = AF_INET6;
dst->sin6_addr = ip6->ip6_dst;
rin6.ro_rt = in6_rtalloc1((struct sockaddr *)dst, 0, 0, M_GETFIB(m));
if (rin6.ro_rt)
RT_UNLOCK(rin6.ro_rt);
#define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key))
/*
* Accept the packet if the forwarding interface to the destination
* according to the routing table is the loopback interface,
* unless the associated route has a gateway.
* Note that this approach causes to accept a packet if there is a
* route to the loopback interface for the destination of the packet.
* But we think it's even useful in some situations, e.g. when using
* a special daemon which wants to intercept the packet.
*
* XXX: some OSes automatically make a cloned route for the destination
* of an outgoing packet. If the outgoing interface of the packet
* is a loopback one, the kernel would consider the packet to be
* accepted, even if we have no such address assinged on the interface.
* We check the cloned flag of the route entry to reject such cases,
* assuming that route entries for our own addresses are not made by
* cloning (it should be true because in6_addloop explicitly installs
* the host route). However, we might have to do an explicit check
* while it would be less efficient. Or, should we rather install a
* reject route for such a case?
*/
if (rin6.ro_rt &&
(rin6.ro_rt->rt_flags &
(RTF_HOST|RTF_GATEWAY)) == RTF_HOST &&
#ifdef RTF_WASCLONED
!(rin6.ro_rt->rt_flags & RTF_WASCLONED) &&
#endif
#ifdef RTF_CLONED
!(rin6.ro_rt->rt_flags & RTF_CLONED) &&
#endif
#if 0
/*
* The check below is redundant since the comparison of
* the destination and the key of the rtentry has
* already done through looking up the routing table.
*/
IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
&rt6_key(rin6.ro_rt)->sin6_addr)
#endif
rin6.ro_rt->rt_ifp->if_type == IFT_LOOP) {
int free_ia6 = 0;
struct in6_ifaddr *ia6;
/*
* found the loopback route to the interface address
*/
if (rin6.ro_rt->rt_gateway->sa_family == AF_LINK) {
struct sockaddr_in6 dest6;
bzero(&dest6, sizeof(dest6));
dest6.sin6_family = AF_INET6;
dest6.sin6_len = sizeof(dest6);
dest6.sin6_addr = ip6->ip6_dst;
ia6 = (struct in6_ifaddr *)
ifa_ifwithaddr((struct sockaddr *)&dest6);
if (ia6 == NULL)
goto bad;
free_ia6 = 1;
}
else
ia6 = (struct in6_ifaddr *)rin6.ro_rt->rt_ifa;
/*
* record address information into m_tag.
*/
(void)ip6_setdstifaddr(m, ia6);
/*
* packets to a tentative, duplicated, or somehow invalid
* address must not be accepted.
*/
if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
/* this address is ready */
ours = 1;
deliverifp = ia6->ia_ifp; /* correct? */
/* Count the packet in the ip address stats */
ia6->ia_ifa.if_ipackets++;
ia6->ia_ifa.if_ibytes += m->m_pkthdr.len;
if (ia6 != NULL && free_ia6 != 0)
ifa_free(&ia6->ia_ifa);
goto hbhcheck;
} else {
char ip6bufs[INET6_ADDRSTRLEN];
char ip6bufd[INET6_ADDRSTRLEN];
/* address is not ready, so discard the packet. */
nd6log((LOG_INFO,
"ip6_input: packet to an unready address %s->%s\n",
ip6_sprintf(ip6bufs, &ip6->ip6_src),
ip6_sprintf(ip6bufd, &ip6->ip6_dst)));
if (ia6 != NULL && free_ia6 != 0)
ifa_free(&ia6->ia_ifa);
goto bad;
}
}
/*
* FAITH (Firewall Aided Internet Translator)
*/
if (V_ip6_keepfaith) {
if (rin6.ro_rt && rin6.ro_rt->rt_ifp &&
rin6.ro_rt->rt_ifp->if_type == IFT_FAITH) {
/* XXX do we need more sanity checks? */
ours = 1;
deliverifp = rin6.ro_rt->rt_ifp; /* faith */
goto hbhcheck;
}
}
/*
* Now there is no reason to process the packet if it's not our own
* and we're not a router.
*/
if (!V_ip6_forwarding) {
V_ip6stat.ip6s_cantforward++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
goto bad;
}
hbhcheck:
/*
* record address information into m_tag, if we don't have one yet.
* note that we are unable to record it, if the address is not listed
* as our interface address (e.g. multicast addresses, addresses
* within FAITH prefixes and such).
*/
if (deliverifp && !ip6_getdstifaddr(m)) {
struct in6_ifaddr *ia6;
ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst);
if (ia6) {
if (!ip6_setdstifaddr(m, ia6)) {
/*
* XXX maybe we should drop the packet here,
* as we could not provide enough information
* to the upper layers.
*/
}
ifa_free(&ia6->ia_ifa);
}
}
/*
* Process Hop-by-Hop options header if it's contained.
* m may be modified in ip6_hopopts_input().
* If a JumboPayload option is included, plen will also be modified.
*/
plen = (u_int32_t)ntohs(ip6->ip6_plen);
if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
int error;
error = ip6_input_hbh(m, &plen, &rtalert, &off, &nxt, &ours);
if (error != 0)
goto out;
} else
nxt = ip6->ip6_nxt;
/*
* Check that the amount of data in the buffers
* is as at least much as the IPv6 header would have us expect.
* Trim mbufs if longer than we expect.
* Drop packet if shorter than we expect.
*/
if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
V_ip6stat.ip6s_tooshort++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
goto bad;
}
if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
if (m->m_len == m->m_pkthdr.len) {
m->m_len = sizeof(struct ip6_hdr) + plen;
m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen;
} else
m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len);
}
/*
* Forward if desirable.
*/
if (V_ip6_mrouter &&
IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
/*
* If we are acting as a multicast router, all
* incoming multicast packets are passed to the
* kernel-level multicast forwarding function.
* The packet is returned (relatively) intact; if
* ip6_mforward() returns a non-zero value, the packet
* must be discarded, else it may be accepted below.
*
* XXX TODO: Check hlim and multicast scope here to avoid
* unnecessarily calling into ip6_mforward().
*/
if (ip6_mforward &&
ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) {
IP6STAT_INC(ip6s_cantforward);
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
goto bad;
}
} else if (!ours) {
ip6_forward(m, srcrt);
goto out;
}
ip6 = mtod(m, struct ip6_hdr *);
/*
* Malicious party may be able to use IPv4 mapped addr to confuse
* tcp/udp stack and bypass security checks (act as if it was from
* 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious.
*
* For SIIT end node behavior, you may want to disable the check.
* However, you will become vulnerable to attacks using IPv4 mapped
* source.
*/
if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
V_ip6stat.ip6s_badscope++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
goto bad;
}
/*
* Tell launch routine the next header
*/
V_ip6stat.ip6s_delivered++;
in6_ifstat_inc(deliverifp, ifs6_in_deliver);
nest = 0;
while (nxt != IPPROTO_DONE) {
if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) {
V_ip6stat.ip6s_toomanyhdr++;
goto bad;
}
/*
* protection against faulty packet - there should be
* more sanity checks in header chain processing.
*/
if (m->m_pkthdr.len < off) {
V_ip6stat.ip6s_tooshort++;
in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
goto bad;
}
#ifdef IPSEC
/*
* enforce IPsec policy checking if we are seeing last header.
* note that we do not visit this with protocols with pcb layer
* code - like udp/tcp/raw ip.
*/
if (ip6_ipsec_input(m, nxt))
goto bad;
#endif /* IPSEC */
/*
* Use mbuf flags to propagate Router Alert option to
* ICMPv6 layer, as hop-by-hop options have been stripped.
*/
if (nxt == IPPROTO_ICMPV6 && rtalert != ~0)
m->m_flags |= M_RTALERT_MLD;
nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt);
}
goto out;
bad:
m_freem(m);
out:
if (rin6.ro_rt)
RTFREE(rin6.ro_rt);
}
/*
* set/grab in6_ifaddr correspond to IPv6 destination address.
* XXX backward compatibility wrapper
*
* XXXRW: We should bump the refcount on ia6 before sticking it in the m_tag,
* and then bump it when the tag is copied, and release it when the tag is
* freed. Unfortunately, m_tags don't support deep copies (yet), so instead
* we just bump the ia refcount when we receive it. This should be fixed.
*/
static struct ip6aux *
ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6)
{
struct ip6aux *ip6a;
ip6a = ip6_addaux(m);
if (ip6a)
ip6a->ip6a_dstia6 = ia6;
return ip6a; /* NULL if failed to set */
}
struct in6_ifaddr *
ip6_getdstifaddr(struct mbuf *m)
{
struct ip6aux *ip6a;
struct in6_ifaddr *ia;
ip6a = ip6_findaux(m);
if (ip6a) {
ia = ip6a->ip6a_dstia6;
ifa_ref(&ia->ia_ifa);
return ia;
} else
return NULL;
}
/*
* Hop-by-Hop options header processing. If a valid jumbo payload option is
* included, the real payload length will be stored in plenp.
*
* rtalertp - XXX: should be stored more smart way
*/
static int
ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp,
struct mbuf **mp, int *offp)
{
struct mbuf *m = *mp;
int off = *offp, hbhlen;
struct ip6_hbh *hbh;
u_int8_t *opt;
/* validation of the length of the header */
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1);
hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
hbhlen = (hbh->ip6h_len + 1) << 3;
IP6_EXTHDR_CHECK(m, off, hbhlen, -1);
hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
#else
IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
sizeof(struct ip6_hdr), sizeof(struct ip6_hbh));
if (hbh == NULL) {
V_ip6stat.ip6s_tooshort++;
return -1;
}
hbhlen = (hbh->ip6h_len + 1) << 3;
IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
hbhlen);
if (hbh == NULL) {
V_ip6stat.ip6s_tooshort++;
return -1;
}
#endif
off += hbhlen;
hbhlen -= sizeof(struct ip6_hbh);
opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh);
if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh),
hbhlen, rtalertp, plenp) < 0)
return (-1);
*offp = off;
*mp = m;
return (0);
}
/*
* Search header for all Hop-by-hop options and process each option.
* This function is separate from ip6_hopopts_input() in order to
* handle a case where the sending node itself process its hop-by-hop
* options header. In such a case, the function is called from ip6_output().
*
* The function assumes that hbh header is located right after the IPv6 header
* (RFC2460 p7), opthead is pointer into data content in m, and opthead to
* opthead + hbhlen is located in contiguous memory region.
*/
int
ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen,
u_int32_t *rtalertp, u_int32_t *plenp)
{
struct ip6_hdr *ip6;
int optlen = 0;
u_int8_t *opt = opthead;
u_int16_t rtalert_val;
u_int32_t jumboplen;
const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh);
for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
switch (*opt) {
case IP6OPT_PAD1:
optlen = 1;
break;
case IP6OPT_PADN:
if (hbhlen < IP6OPT_MINLEN) {
V_ip6stat.ip6s_toosmall++;
goto bad;
}
optlen = *(opt + 1) + 2;
break;
case IP6OPT_ROUTER_ALERT:
/* XXX may need check for alignment */
if (hbhlen < IP6OPT_RTALERT_LEN) {
V_ip6stat.ip6s_toosmall++;
goto bad;
}
if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
/* XXX stat */
icmp6_error(m, ICMP6_PARAM_PROB,
ICMP6_PARAMPROB_HEADER,
erroff + opt + 1 - opthead);
return (-1);
}
optlen = IP6OPT_RTALERT_LEN;
bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2);
*rtalertp = ntohs(rtalert_val);
break;
case IP6OPT_JUMBO:
/* XXX may need check for alignment */
if (hbhlen < IP6OPT_JUMBO_LEN) {
V_ip6stat.ip6s_toosmall++;
goto bad;
}
if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
/* XXX stat */
icmp6_error(m, ICMP6_PARAM_PROB,
ICMP6_PARAMPROB_HEADER,
erroff + opt + 1 - opthead);
return (-1);
}
optlen = IP6OPT_JUMBO_LEN;
/*
* IPv6 packets that have non 0 payload length
* must not contain a jumbo payload option.
*/
ip6 = mtod(m, struct ip6_hdr *);
if (ip6->ip6_plen) {
V_ip6stat.ip6s_badoptions++;
icmp6_error(m, ICMP6_PARAM_PROB,
ICMP6_PARAMPROB_HEADER,
erroff + opt - opthead);
return (-1);
}
/*
* We may see jumbolen in unaligned location, so
* we'd need to perform bcopy().
*/
bcopy(opt + 2, &jumboplen, sizeof(jumboplen));
jumboplen = (u_int32_t)htonl(jumboplen);
#if 1
/*
* if there are multiple jumbo payload options,
* *plenp will be non-zero and the packet will be
* rejected.
* the behavior may need some debate in ipngwg -
* multiple options does not make sense, however,
* there's no explicit mention in specification.
*/
if (*plenp != 0) {
V_ip6stat.ip6s_badoptions++;
icmp6_error(m, ICMP6_PARAM_PROB,
ICMP6_PARAMPROB_HEADER,
erroff + opt + 2 - opthead);
return (-1);
}
#endif
/*
* jumbo payload length must be larger than 65535.
*/
if (jumboplen <= IPV6_MAXPACKET) {
V_ip6stat.ip6s_badoptions++;
icmp6_error(m, ICMP6_PARAM_PROB,
ICMP6_PARAMPROB_HEADER,
erroff + opt + 2 - opthead);
return (-1);
}
*plenp = jumboplen;
break;
default: /* unknown option */
if (hbhlen < IP6OPT_MINLEN) {
V_ip6stat.ip6s_toosmall++;
goto bad;
}
optlen = ip6_unknown_opt(opt, m,
erroff + opt - opthead);
if (optlen == -1)
return (-1);
optlen += 2;
break;
}
}
return (0);
bad:
m_freem(m);
return (-1);
}
/*
* Unknown option processing.
* The third argument `off' is the offset from the IPv6 header to the option,
* which is necessary if the IPv6 header the and option header and IPv6 header
* is not contiguous in order to return an ICMPv6 error.
*/
int
ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off)
{
struct ip6_hdr *ip6;
switch (IP6OPT_TYPE(*optp)) {
case IP6OPT_TYPE_SKIP: /* ignore the option */
return ((int)*(optp + 1));
case IP6OPT_TYPE_DISCARD: /* silently discard */
m_freem(m);
return (-1);
case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */
V_ip6stat.ip6s_badoptions++;
icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
return (-1);
case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
V_ip6stat.ip6s_badoptions++;
ip6 = mtod(m, struct ip6_hdr *);
if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
(m->m_flags & (M_BCAST|M_MCAST)))
m_freem(m);
else
icmp6_error(m, ICMP6_PARAM_PROB,
ICMP6_PARAMPROB_OPTION, off);
return (-1);
}
m_freem(m); /* XXX: NOTREACHED */
return (-1);
}
/*
* Create the "control" list for this pcb.
* These functions will not modify mbuf chain at all.
*
* With KAME mbuf chain restriction:
* The routine will be called from upper layer handlers like tcp6_input().
* Thus the routine assumes that the caller (tcp6_input) have already
* called IP6_EXTHDR_CHECK() and all the extension headers are located in the
* very first mbuf on the mbuf chain.
*
* ip6_savecontrol_v4 will handle those options that are possible to be
* set on a v4-mapped socket.
* ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those
* options and handle the v6-only ones itself.
*/
struct mbuf **
ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp,
int *v4only)
{
struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
#ifdef SO_TIMESTAMP
if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) {
struct timeval tv;
microtime(&tv);
*mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
SCM_TIMESTAMP, SOL_SOCKET);
if (*mp)
mp = &(*mp)->m_next;
}
#endif
if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
if (v4only != NULL)
*v4only = 1;
return (mp);
}
#define IS2292(inp, x, y) (((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y))
/* RFC 2292 sec. 5 */
if ((inp->inp_flags & IN6P_PKTINFO) != 0) {
struct in6_pktinfo pi6;
bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr));
in6_clearscope(&pi6.ipi6_addr); /* XXX */
pi6.ipi6_ifindex =
(m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0;
*mp = sbcreatecontrol((caddr_t) &pi6,
sizeof(struct in6_pktinfo),
IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6);
if (*mp)
mp = &(*mp)->m_next;
}
if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) {
int hlim = ip6->ip6_hlim & 0xff;
*mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int),
IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT),
IPPROTO_IPV6);
if (*mp)
mp = &(*mp)->m_next;
}
if (v4only != NULL)
*v4only = 0;
return (mp);
}
void
ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp)
{
struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
int v4only = 0;
mp = ip6_savecontrol_v4(in6p, m, mp, &v4only);
if (v4only)
return;
if ((in6p->inp_flags & IN6P_TCLASS) != 0) {
u_int32_t flowinfo;
int tclass;
flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK);
flowinfo >>= 20;
tclass = flowinfo & 0xff;
*mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass),
IPV6_TCLASS, IPPROTO_IPV6);
if (*mp)
mp = &(*mp)->m_next;
}
/*
* IPV6_HOPOPTS socket option. Recall that we required super-user
* privilege for the option (see ip6_ctloutput), but it might be too
* strict, since there might be some hop-by-hop options which can be
* returned to normal user.
* See also RFC 2292 section 6 (or RFC 3542 section 8).
*/
if ((in6p->inp_flags & IN6P_HOPOPTS) != 0) {
/*
* Check if a hop-by-hop options header is contatined in the
* received packet, and if so, store the options as ancillary
* data. Note that a hop-by-hop options header must be
* just after the IPv6 header, which is assured through the
* IPv6 input processing.
*/
if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
struct ip6_hbh *hbh;
int hbhlen = 0;
#ifdef PULLDOWN_TEST
struct mbuf *ext;
#endif
#ifndef PULLDOWN_TEST
hbh = (struct ip6_hbh *)(ip6 + 1);
hbhlen = (hbh->ip6h_len + 1) << 3;
#else
ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr),
ip6->ip6_nxt);
if (ext == NULL) {
V_ip6stat.ip6s_tooshort++;
return;
}
hbh = mtod(ext, struct ip6_hbh *);
hbhlen = (hbh->ip6h_len + 1) << 3;
if (hbhlen != ext->m_len) {
m_freem(ext);
V_ip6stat.ip6s_tooshort++;
return;
}
#endif
/*
* XXX: We copy the whole header even if a
* jumbo payload option is included, the option which
* is to be removed before returning according to
* RFC2292.
* Note: this constraint is removed in RFC3542
*/
*mp = sbcreatecontrol((caddr_t)hbh, hbhlen,
IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS),
IPPROTO_IPV6);
if (*mp)
mp = &(*mp)->m_next;
#ifdef PULLDOWN_TEST
m_freem(ext);
#endif
}
}
if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) {
int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);
/*
* Search for destination options headers or routing
* header(s) through the header chain, and stores each
* header as ancillary data.
* Note that the order of the headers remains in
* the chain of ancillary data.
*/
while (1) { /* is explicit loop prevention necessary? */
struct ip6_ext *ip6e = NULL;
int elen;
#ifdef PULLDOWN_TEST
struct mbuf *ext = NULL;
#endif
/*
* if it is not an extension header, don't try to
* pull it from the chain.
*/
switch (nxt) {
case IPPROTO_DSTOPTS:
case IPPROTO_ROUTING:
case IPPROTO_HOPOPTS:
case IPPROTO_AH: /* is it possible? */
break;
default:
goto loopend;
}
#ifndef PULLDOWN_TEST
if (off + sizeof(*ip6e) > m->m_len)
goto loopend;
ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
if (nxt == IPPROTO_AH)
elen = (ip6e->ip6e_len + 2) << 2;
else
elen = (ip6e->ip6e_len + 1) << 3;
if (off + elen > m->m_len)
goto loopend;
#else
ext = ip6_pullexthdr(m, off, nxt);
if (ext == NULL) {
V_ip6stat.ip6s_tooshort++;
return;
}
ip6e = mtod(ext, struct ip6_ext *);
if (nxt == IPPROTO_AH)
elen = (ip6e->ip6e_len + 2) << 2;
else
elen = (ip6e->ip6e_len + 1) << 3;
if (elen != ext->m_len) {
m_freem(ext);
V_ip6stat.ip6s_tooshort++;
return;
}
#endif
switch (nxt) {
case IPPROTO_DSTOPTS:
if (!(in6p->inp_flags & IN6P_DSTOPTS))
break;
*mp = sbcreatecontrol((caddr_t)ip6e, elen,
IS2292(in6p,
IPV6_2292DSTOPTS, IPV6_DSTOPTS),
IPPROTO_IPV6);
if (*mp)
mp = &(*mp)->m_next;
break;
case IPPROTO_ROUTING:
if (!(in6p->inp_flags & IN6P_RTHDR))
break;
*mp = sbcreatecontrol((caddr_t)ip6e, elen,
IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR),
IPPROTO_IPV6);
if (*mp)
mp = &(*mp)->m_next;
break;
case IPPROTO_HOPOPTS:
case IPPROTO_AH: /* is it possible? */
break;
default:
/*
* other cases have been filtered in the above.
* none will visit this case. here we supply
* the code just in case (nxt overwritten or
* other cases).
*/
#ifdef PULLDOWN_TEST
m_freem(ext);
#endif
goto loopend;
}
/* proceed with the next header. */
off += elen;
nxt = ip6e->ip6e_nxt;
ip6e = NULL;
#ifdef PULLDOWN_TEST
m_freem(ext);
ext = NULL;
#endif
}
loopend:
;
}
}
#undef IS2292
void
ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu)
{
struct socket *so;
struct mbuf *m_mtu;
struct ip6_mtuinfo mtuctl;
so = in6p->inp_socket;
if (mtu == NULL)
return;
#ifdef DIAGNOSTIC
if (so == NULL) /* I believe this is impossible */
panic("ip6_notify_pmtu: socket is NULL");
#endif
bzero(&mtuctl, sizeof(mtuctl)); /* zero-clear for safety */
mtuctl.ip6m_mtu = *mtu;
mtuctl.ip6m_addr = *dst;
if (sa6_recoverscope(&mtuctl.ip6m_addr))
return;
if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl),
IPV6_PATHMTU, IPPROTO_IPV6)) == NULL)
return;
if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu)
== 0) {
m_freem(m_mtu);
/* XXX: should count statistics */
} else
sorwakeup(so);
return;
}
#ifdef PULLDOWN_TEST
/*
* pull single extension header from mbuf chain. returns single mbuf that
* contains the result, or NULL on error.
*/
static struct mbuf *
ip6_pullexthdr(struct mbuf *m, size_t off, int nxt)
{
struct ip6_ext ip6e;
size_t elen;
struct mbuf *n;
#ifdef DIAGNOSTIC
switch (nxt) {
case IPPROTO_DSTOPTS:
case IPPROTO_ROUTING:
case IPPROTO_HOPOPTS:
case IPPROTO_AH: /* is it possible? */
break;
default:
printf("ip6_pullexthdr: invalid nxt=%d\n", nxt);
}
#endif
m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
if (nxt == IPPROTO_AH)
elen = (ip6e.ip6e_len + 2) << 2;
else
elen = (ip6e.ip6e_len + 1) << 3;
MGET(n, M_DONTWAIT, MT_DATA);
if (n && elen >= MLEN) {
MCLGET(n, M_DONTWAIT);
if ((n->m_flags & M_EXT) == 0) {
m_free(n);
n = NULL;
}
}
if (!n)
return NULL;
n->m_len = 0;
if (elen >= M_TRAILINGSPACE(n)) {
m_free(n);
return NULL;
}
m_copydata(m, off, elen, mtod(n, caddr_t));
n->m_len = elen;
return n;
}
#endif
/*
* Get pointer to the previous header followed by the header
* currently processed.
* XXX: This function supposes that
* M includes all headers,
* the next header field and the header length field of each header
* are valid, and
* the sum of each header length equals to OFF.
* Because of these assumptions, this function must be called very
* carefully. Moreover, it will not be used in the near future when
* we develop `neater' mechanism to process extension headers.
*/
char *
ip6_get_prevhdr(struct mbuf *m, int off)
{
struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
if (off == sizeof(struct ip6_hdr))
return (&ip6->ip6_nxt);
else {
int len, nxt;
struct ip6_ext *ip6e = NULL;
nxt = ip6->ip6_nxt;
len = sizeof(struct ip6_hdr);
while (len < off) {
ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len);
switch (nxt) {
case IPPROTO_FRAGMENT:
len += sizeof(struct ip6_frag);
break;
case IPPROTO_AH:
len += (ip6e->ip6e_len + 2) << 2;
break;
default:
len += (ip6e->ip6e_len + 1) << 3;
break;
}
nxt = ip6e->ip6e_nxt;
}
if (ip6e)
return (&ip6e->ip6e_nxt);
else
return NULL;
}
}
/*
* get next header offset. m will be retained.
*/
int
ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp)
{
struct ip6_hdr ip6;
struct ip6_ext ip6e;
struct ip6_frag fh;
/* just in case */
if (m == NULL)
panic("ip6_nexthdr: m == NULL");
if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off)
return -1;
switch (proto) {
case IPPROTO_IPV6:
if (m->m_pkthdr.len < off + sizeof(ip6))
return -1;
m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6);
if (nxtp)
*nxtp = ip6.ip6_nxt;
off += sizeof(ip6);
return off;
case IPPROTO_FRAGMENT:
/*
* terminate parsing if it is not the first fragment,
* it does not make sense to parse through it.
*/
if (m->m_pkthdr.len < off + sizeof(fh))
return -1;
m_copydata(m, off, sizeof(fh), (caddr_t)&fh);
/* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */
if (fh.ip6f_offlg & IP6F_OFF_MASK)
return -1;
if (nxtp)
*nxtp = fh.ip6f_nxt;
off += sizeof(struct ip6_frag);
return off;
case IPPROTO_AH:
if (m->m_pkthdr.len < off + sizeof(ip6e))
return -1;
m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
if (nxtp)
*nxtp = ip6e.ip6e_nxt;
off += (ip6e.ip6e_len + 2) << 2;
return off;
case IPPROTO_HOPOPTS:
case IPPROTO_ROUTING:
case IPPROTO_DSTOPTS:
if (m->m_pkthdr.len < off + sizeof(ip6e))
return -1;
m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
if (nxtp)
*nxtp = ip6e.ip6e_nxt;
off += (ip6e.ip6e_len + 1) << 3;
return off;
case IPPROTO_NONE:
case IPPROTO_ESP:
case IPPROTO_IPCOMP:
/* give up */
return -1;
default:
return -1;
}
return -1;
}
/*
* get offset for the last header in the chain. m will be kept untainted.
*/
int
ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp)
{
int newoff;
int nxt;
if (!nxtp) {
nxt = -1;
nxtp = &nxt;
}
while (1) {
newoff = ip6_nexthdr(m, off, proto, nxtp);
if (newoff < 0)
return off;
else if (newoff < off)
return -1; /* invalid */
else if (newoff == off)
return newoff;
off = newoff;
proto = *nxtp;
}
}
static struct ip6aux *
ip6_addaux(struct mbuf *m)
{
struct m_tag *mtag;
mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
if (!mtag) {
mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux),
M_NOWAIT);
if (mtag) {
m_tag_prepend(m, mtag);
bzero(mtag + 1, sizeof(struct ip6aux));
}
}
return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
}
static struct ip6aux *
ip6_findaux(struct mbuf *m)
{
struct m_tag *mtag;
mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
}
static void
ip6_delaux(struct mbuf *m)
{
struct m_tag *mtag;
mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
if (mtag)
m_tag_delete(m, mtag);
}
/*
* System control for IP6
*/
u_char inet6ctlerrmap[PRC_NCMDS] = {
0, 0, 0, 0,
0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
EMSGSIZE, EHOSTUNREACH, 0, 0,
0, 0, 0, 0,
ENOPROTOOPT
};
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