gems-kernel/source/THIRDPARTY/xnu/bsd/netinet6/in6_gif.c
2024-06-03 11:29:39 -05:00

415 lines
11 KiB
C

/*
* Copyright (c) 2009-2016 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/* $FreeBSD: src/sys/netinet6/in6_gif.c,v 1.2.2.3 2001/07/03 11:01:52 ume Exp $ */
/* $KAME: in6_gif.c,v 1.49 2001/05/14 14:02:17 itojun Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/mbuf.h>
#include <sys/errno.h>
#include <sys/queue.h>
#include <sys/syslog.h>
#include <sys/malloc.h>
#include <sys/protosw.h>
#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#if INET
#include <netinet/ip.h>
#endif
#include <netinet/ip_encap.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/in6_gif.h>
#include <netinet6/in6_var.h>
#include <netinet/ip_ecn.h>
#include <netinet6/ip6_ecn.h>
#include <net/if_gif.h>
#include <net/net_osdep.h>
#include <net/sockaddr_utils.h>
int
in6_gif_output(
struct ifnet *ifp,
int family, /* family of the packet to be encapsulate. */
struct mbuf *m,
__unused struct rtentry *rt)
{
struct gif_softc *sc = ifnet_softc(ifp);
struct sockaddr_in6 *dst = SIN6(&sc->gif_ro6.ro_dst);
struct sockaddr_in6 *sin6_src = SIN6(sc->gif_psrc);
struct sockaddr_in6 *sin6_dst = SIN6(sc->gif_pdst);
struct ip6_hdr *ip6;
int proto;
u_int8_t itos, otos;
GIF_LOCK_ASSERT(sc);
if (sin6_src == NULL || sin6_dst == NULL ||
sin6_src->sin6_family != AF_INET6 ||
sin6_dst->sin6_family != AF_INET6) {
m_freem(m);
return EAFNOSUPPORT;
}
switch (family) {
#if INET
case AF_INET:
{
struct ip *ip;
proto = IPPROTO_IPV4;
if (mbuf_len(m) < sizeof(*ip)) {
m = m_pullup(m, sizeof(*ip));
if (!m) {
return ENOBUFS;
}
}
ip = mtod(m, struct ip *);
itos = ip->ip_tos;
break;
}
#endif
case AF_INET6:
{
proto = IPPROTO_IPV6;
if (mbuf_len(m) < sizeof(*ip6)) {
m = m_pullup(m, sizeof(*ip6));
if (!m) {
return ENOBUFS;
}
}
ip6 = mtod(m, struct ip6_hdr *);
itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
break;
}
default:
#if DEBUG
printf("in6_gif_output: warning: unknown family %d passed\n",
family);
#endif
m_freem(m);
return EAFNOSUPPORT;
}
/* prepend new IP header */
M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT, 1);
if (m && mbuf_len(m) < sizeof(struct ip6_hdr)) {
m = m_pullup(m, sizeof(struct ip6_hdr));
}
if (m == NULL) {
printf("ENOBUFS in in6_gif_output %d\n", __LINE__);
return ENOBUFS;
}
ip6 = mtod(m, struct ip6_hdr *);
ip6->ip6_flow = 0;
ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
ip6->ip6_vfc |= IPV6_VERSION;
ip6->ip6_plen = htons((u_short)m->m_pkthdr.len);
ip6->ip6_nxt = proto;
ip6->ip6_hlim = ip6_gif_hlim;
ip6->ip6_src = sin6_src->sin6_addr;
ip6_output_setsrcifscope(m, sin6_src->sin6_scope_id, NULL);
ip6_output_setdstifscope(m, sin6_dst->sin6_scope_id, NULL);
/* bidirectional configured tunnel mode */
if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr)) {
ip6->ip6_dst = sin6_dst->sin6_addr;
} else {
m_freem(m);
return ENETUNREACH;
}
ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_NORMAL : ECN_NOCARE,
&otos, &itos);
ip6->ip6_flow &= ~htonl(0xff << 20);
ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
if (ROUTE_UNUSABLE(&sc->gif_ro6) ||
dst->sin6_family != sin6_dst->sin6_family ||
!IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr) ||
(sc->gif_ro6.ro_rt != NULL && sc->gif_ro6.ro_rt->rt_ifp == ifp)) {
/* cache route doesn't match or recursive route */
SOCKADDR_ZERO(dst, sizeof(*dst));
dst->sin6_family = sin6_dst->sin6_family;
dst->sin6_len = sizeof(struct sockaddr_in6);
dst->sin6_addr = sin6_dst->sin6_addr;
ROUTE_RELEASE(&sc->gif_ro6);
#if 0
sc->gif_if.if_mtu = GIF_MTU;
#endif
}
if (sc->gif_ro6.ro_rt == NULL) {
rtalloc((struct route *)&sc->gif_ro6);
if (sc->gif_ro6.ro_rt == NULL) {
m_freem(m);
return ENETUNREACH;
}
RT_LOCK(sc->gif_ro6.ro_rt);
/* if it constitutes infinite encapsulation, punt. */
if (sc->gif_ro6.ro_rt->rt_ifp == ifp) {
RT_UNLOCK(sc->gif_ro6.ro_rt);
m_freem(m);
return ENETUNREACH; /* XXX */
}
#if 0
ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu
- sizeof(struct ip6_hdr);
#endif
RT_UNLOCK(sc->gif_ro6.ro_rt);
}
#if IPV6_MINMTU
/*
* force fragmentation to minimum MTU, to avoid path MTU discovery.
* it is too painful to ask for resend of inner packet, to achieve
* path MTU discovery for encapsulated packets.
*/
return ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL);
#else
return ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL);
#endif
}
int
in6_gif_input(struct mbuf **mp, int *offp, int proto)
{
struct mbuf *m = *mp;
struct ifnet *gifp = NULL;
struct ip6_hdr *ip6;
int af = 0;
u_int32_t otos;
int egress_success = 0;
ip6 = mtod(m, struct ip6_hdr *);
gifp = ((struct gif_softc *)encap_getarg(m))->gif_if;
if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
m_freem(m);
ip6stat.ip6s_nogif++;
return IPPROTO_DONE;
}
otos = ip6->ip6_flow;
m_adj(m, *offp);
switch (proto) {
case IPPROTO_IPV4:
{
struct ip *ip;
u_int8_t otos8, old_tos;
int sum;
af = AF_INET;
otos8 = (ntohl(otos) >> 20) & 0xff;
if (mbuf_len(m) < sizeof(*ip)) {
m = m_pullup(m, sizeof(*ip));
if (!m) {
return IPPROTO_DONE;
}
}
ip = mtod(m, struct ip *);
if (gifp->if_flags & IFF_LINK1) {
old_tos = ip->ip_tos;
egress_success = ip_ecn_egress(ECN_NORMAL, &otos8, &ip->ip_tos);
if (old_tos != ip->ip_tos) {
sum = ~ntohs(ip->ip_sum) & 0xffff;
sum += (~old_tos & 0xffff) + ip->ip_tos;
sum = (sum >> 16) + (sum & 0xffff);
sum += (sum >> 16); /* add carry */
ip->ip_sum = htons(~sum & 0xffff);
}
} else {
egress_success = ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
}
break;
}
case IPPROTO_IPV6:
{
af = AF_INET6;
if (mbuf_len(m) < sizeof(*ip6)) {
m = m_pullup(m, sizeof(*ip6));
if (!m) {
return IPPROTO_DONE;
}
}
ip6 = mtod(m, struct ip6_hdr *);
if (gifp->if_flags & IFF_LINK1) {
egress_success = ip6_ecn_egress(ECN_NORMAL, &otos, &ip6->ip6_flow);
} else {
egress_success = ip6_ecn_egress(ECN_NOCARE, &otos, &ip6->ip6_flow);
}
break;
}
default:
ip6stat.ip6s_nogif++;
m_freem(m);
return IPPROTO_DONE;
}
if (egress_success == 0) {
ip6stat.ip6s_nogif++;
m_freem(m);
return IPPROTO_DONE;
}
/* Replace the rcvif by gifp for ifnet_input to route it correctly */
if (m->m_pkthdr.rcvif) {
m->m_pkthdr.rcvif = gifp;
}
ifnet_input(gifp, m, NULL);
return IPPROTO_DONE;
}
/*
* validate outer address.
*/
static int
gif_validate6(
const struct ip6_hdr *ip6,
struct gif_softc *sc,
struct ifnet *ifp)
{
struct sockaddr_in6 *src, *dst;
src = SIN6(sc->gif_psrc);
dst = SIN6(sc->gif_pdst);
/*
* Check for address match. Note that the check is for an incoming
* packet. We should compare the *source* address in our configuration
* and the *destination* address of the packet, and vice versa.
*/
if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) ||
!IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src)) {
return 0;
}
/* martian filters on outer source - done in ip6_input */
/* ingress filters on outer source */
if ((ifnet_flags(sc->gif_if) & IFF_LINK2) == 0 && ifp) {
struct sockaddr_in6 sin6;
struct rtentry *rt;
SOCKADDR_ZERO(&sin6, sizeof(sin6));
sin6.sin6_family = AF_INET6;
sin6.sin6_len = sizeof(struct sockaddr_in6);
sin6.sin6_addr = ip6->ip6_src;
rt = rtalloc1(SA(&sin6), 0, 0);
if (rt != NULL) {
RT_LOCK(rt);
}
if (!rt || rt->rt_ifp != ifp) {
#if 0
log(LOG_WARNING, "%s: packet from %s dropped "
"due to ingress filter\n", if_name(&sc->gif_if),
ip6_sprintf(&sin6.sin6_addr));
#endif
if (rt != NULL) {
RT_UNLOCK(rt);
rtfree(rt);
}
return 0;
}
RT_UNLOCK(rt);
rtfree(rt);
}
return 128 * 2;
}
/*
* we know that we are in IFF_UP, outer address available, and outer family
* matched the physical addr family. see gif_encapcheck().
* sanity check for arg should have been done in the caller.
*/
int
gif_encapcheck6(
const struct mbuf *m,
__unused int off,
__unused int proto,
void *arg)
{
struct ip6_hdr ip6;
struct gif_softc *sc;
struct ifnet *ifp;
/* sanity check done in caller */
sc = (struct gif_softc *)arg;
GIF_LOCK_ASSERT(sc);
mbuf_copydata((struct mbuf *)(size_t)m, 0, sizeof(ip6), &ip6);
ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
return gif_validate6(&ip6, sc, ifp);
}