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freebsd-nq/sys/netinet6/ip6_input.c
Bjoern A. Zeeb 8a006adb24 Add support for IPv6 to ipfw fwd: 
Distinguish IPv4 and IPv6 addresses and optional port numbers in
user space to set the option for the correct protocol family.
Add support in the kernel for carrying the new IPv6 destination
address and port.
Add support to TCP and UDP for IPv6 and fix UDP IPv4 to not change
the address in the IP header.
Add support for IPv6 forwarding to a non-local destination.
Add a regession test uitilizing VIMAGE to check all 20 possible
combinations I could think of.

Obtained from:	David Dolson at Sandvine Incorporated
		(original version for ipfw fwd IPv6 support)
Sponsored by:	Sandvine Incorporated
PR:		bin/117214
MFC after:	4 weeks
Approved by:	re (kib)
2011-08-20 17:05:11 +00:00

1821 lines
47 KiB
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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: 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 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);
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);
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_LOCK(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_UNLOCK(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 = rtalloc1((struct sockaddr *)dst, 0, 0);
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) {
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;
}
}
} 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;
}
}
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;
}
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;
}
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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