/*
* Copyright (c) 2000-2018 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@
*/
/* $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 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/kernel.h>
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <libkern/OSAtomic.h>
#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/in_gif.h>
#include <netinet/in_var.h>
#include <netinet/ip_encap.h>
#include <netinet/ip_ecn.h>
#include <netinet/ip6.h>
#include <net/if_gif.h>
#include <net/net_osdep.h>
#include <net/sockaddr_utils.h>
int ip_gif_ttl = GIF_TTL;
SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW | CTLFLAG_LOCKED,
&ip_gif_ttl, 0, "");
int
in_gif_output(
struct ifnet *ifp,
int family,
struct mbuf *m,
__unused struct rtentry *rt)
{
struct gif_softc *__single sc = ifnet_softc(ifp);
struct sockaddr_in *__single dst = SIN(&sc->gif_ro.ro_dst);
struct sockaddr_in *__single sin_src = SIN(sc->gif_psrc);
struct sockaddr_in *__single sin_dst = SIN(sc->gif_pdst);
struct ip iphdr; /* capsule IP header, host byte ordered */
int proto, error;
u_int8_t tos;
struct ip_out_args ipoa;
bzero(&ipoa, sizeof(ipoa));
ipoa.ipoa_boundif = IFSCOPE_NONE;
ipoa.ipoa_flags = IPOAF_SELECT_SRCIF;
ipoa.ipoa_sotc = SO_TC_UNSPEC;
ipoa.ipoa_netsvctype = _NET_SERVICE_TYPE_UNSPEC;
GIF_LOCK_ASSERT(sc);
if (sin_src == NULL || sin_dst == NULL ||
sin_src->sin_family != AF_INET ||
sin_dst->sin_family != AF_INET) {
m_freem(m);
return EAFNOSUPPORT;
}
switch (family) {
#if INET
case AF_INET:
{
struct ip *__single 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 *);
tos = ip->ip_tos;
break;
}
#endif /* INET */
case AF_INET6:
{
struct ip6_hdr *ip6;
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 *);
tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
break;
}
default:
#if DEBUG
printf("in_gif_output: warning: unknown family %d passed\n",
family);
#endif
m_freem(m);
return EAFNOSUPPORT;
}
bzero(&iphdr, sizeof(iphdr));
iphdr.ip_src = sin_src->sin_addr;
/* bidirectional configured tunnel mode */
if (sin_dst->sin_addr.s_addr != INADDR_ANY) {
iphdr.ip_dst = sin_dst->sin_addr;
} else {
m_freem(m);
return ENETUNREACH;
}
iphdr.ip_p = proto;
/* version will be set in ip_output() */
iphdr.ip_ttl = ip_gif_ttl;
iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip);
if (ifp->if_flags & IFF_LINK1) {
ip_ecn_ingress(ECN_NORMAL, &iphdr.ip_tos, &tos);
} else {
ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos);
}
/* prepend new IP header */
M_PREPEND(m, sizeof(struct ip), M_DONTWAIT, 0);
if (m && mbuf_len(m) < sizeof(struct ip)) {
m = m_pullup(m, sizeof(struct ip));
}
if (m == NULL) {
printf("ENOBUFS in in_gif_output %d\n", __LINE__);
return ENOBUFS;
}
bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip));
if (ROUTE_UNUSABLE(&sc->gif_ro) ||
dst->sin_family != sin_dst->sin_family ||
dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr ||
(sc->gif_ro.ro_rt != NULL && sc->gif_ro.ro_rt->rt_ifp == ifp)) {
/* cache route doesn't match or recursive route */
dst->sin_family = sin_dst->sin_family;
dst->sin_len = sizeof(struct sockaddr_in);
dst->sin_addr = sin_dst->sin_addr;
ROUTE_RELEASE(&sc->gif_ro);
#if 0
sc->gif_if.if_mtu = GIF_MTU;
#endif
}
if (sc->gif_ro.ro_rt == NULL) {
rtalloc(&sc->gif_ro);
if (sc->gif_ro.ro_rt == NULL) {
m_freem(m);
return ENETUNREACH;
}
/* if it constitutes infinite encapsulation, punt. */
RT_LOCK(sc->gif_ro.ro_rt);
if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
RT_UNLOCK(sc->gif_ro.ro_rt);
m_freem(m);
return ENETUNREACH; /* XXX */
}
#if 0
ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu
- sizeof(struct ip);
#endif
RT_UNLOCK(sc->gif_ro.ro_rt);
}
error = ip_output(m, NULL, &sc->gif_ro, IP_OUTARGS, NULL, &ipoa);
return error;
}
void
in_gif_input(struct mbuf *m, int off)
{
struct ifnet *gifp = NULL;
struct ip *ip;
int af, proto;
u_int8_t otos, old_tos;
int egress_success = 0;
int sum;
ip = mtod(m, struct ip *);
proto = ip->ip_p;
gifp = ((struct gif_softc *)encap_getarg(m))->gif_if;
if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
m_freem(m);
OSAddAtomic(1, &ipstat.ips_nogif);
return;
}
otos = ip->ip_tos;
m_adj(m, off);
switch (proto) {
#if INET
case IPPROTO_IPV4:
{
af = AF_INET;
if (mbuf_len(m) < sizeof(*ip)) {
m = m_pullup(m, sizeof(*ip));
if (!m) {
return;
}
}
ip = mtod(m, struct ip *);
if (gifp->if_flags & IFF_LINK1) {
old_tos = ip->ip_tos;
egress_success = ip_ecn_egress(ECN_NORMAL, &otos, &ip->ip_tos);
if (old_tos != ip->ip_tos) {
sum = ~ntohs(ip->ip_sum) & 0xffff;
sum += (~otos & 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, &otos, &ip->ip_tos);
}
break;
}
#endif
case IPPROTO_IPV6:
{
struct ip6_hdr *ip6;
u_int8_t itos;
af = AF_INET6;
if (mbuf_len(m) < sizeof(*ip6)) {
m = m_pullup(m, sizeof(*ip6));
if (!m) {
return;
}
}
ip6 = mtod(m, struct ip6_hdr *);
itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
if (gifp->if_flags & IFF_LINK1) {
egress_success = ip_ecn_egress(ECN_NORMAL, &otos, &itos);
} else {
egress_success = ip_ecn_egress(ECN_NOCARE, &otos, &itos);
}
ip6->ip6_flow &= ~htonl(0xff << 20);
ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
break;
}
default:
OSAddAtomic(1, &ipstat.ips_nogif);
m_freem(m);
return;
}
if (egress_success == 0) {
OSAddAtomic(1, &ipstat.ips_nogif);
m_freem(m);
return;
}
#ifdef __APPLE__
/* Replace the rcvif by gifp for dlil to route it correctly */
if (m->m_pkthdr.rcvif) {
m->m_pkthdr.rcvif = gifp;
}
ifnet_input(gifp, m, NULL);
#else
gif_input(m, af, gifp);
#endif
}
/*
* We know that we are in IFF_UP, outer address available, and outer family
* matched the physical addr family. see gif_encapcheck().
*/
int
gif_encapcheck4(
const struct mbuf *m,
__unused int off,
__unused int proto,
void *arg)
{
struct ip ip;
struct gif_softc *__single sc;
struct sockaddr_in *__single src, *__single dst;
int addrmatch;
struct in_ifaddr *__single ia4;
/* sanity check done in caller */
sc = (struct gif_softc *)arg;
src = SIN(sc->gif_psrc);
dst = SIN(sc->gif_pdst);
GIF_LOCK_ASSERT(sc);
mbuf_copydata(__DECONST(struct mbuf *, m), 0, sizeof(ip), &ip);
/* check for address match */
addrmatch = 0;
if (src->sin_addr.s_addr == ip.ip_dst.s_addr) {
addrmatch |= 1;
}
if (dst->sin_addr.s_addr == ip.ip_src.s_addr) {
addrmatch |= 2;
}
if (addrmatch != 3) {
return 0;
}
/* martian filters on outer source - NOT done in ip_input! */
if (IN_MULTICAST(ntohl(ip.ip_src.s_addr))) {
return 0;
}
switch ((ntohl(ip.ip_src.s_addr) & 0xff000000) >> 24) {
case 0: case 127: case 255:
return 0;
}
/* reject packets with broadcast on source */
lck_rw_lock_shared(&in_ifaddr_rwlock);
for (ia4 = TAILQ_FIRST(&in_ifaddrhead); ia4;
ia4 = TAILQ_NEXT(ia4, ia_link)) {
if ((ifnet_flags(ia4->ia_ifa.ifa_ifp) & IFF_BROADCAST) == 0) {
continue;
}
IFA_LOCK(&ia4->ia_ifa);
if (ip.ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) {
IFA_UNLOCK(&ia4->ia_ifa);
lck_rw_done(&in_ifaddr_rwlock);
return 0;
}
IFA_UNLOCK(&ia4->ia_ifa);
}
lck_rw_done(&in_ifaddr_rwlock);
/* ingress filters on outer source */
if ((ifnet_flags(sc->gif_if) & IFF_LINK2) == 0 &&
(m->m_flags & M_PKTHDR) != 0 && m->m_pkthdr.rcvif) {
struct sockaddr_in sin;
struct rtentry *rt;
SOCKADDR_ZERO(&sin, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_len = sizeof(struct sockaddr_in);
sin.sin_addr = ip.ip_src;
rt = rtalloc1_scoped(SA(&sin), 0, 0,
m->m_pkthdr.rcvif->if_index);
if (rt != NULL) {
RT_LOCK(rt);
}
if (rt == NULL || rt->rt_ifp != m->m_pkthdr.rcvif) {
if (rt != NULL) {
RT_UNLOCK(rt);
rtfree(rt);
}
return 0;
}
RT_UNLOCK(rt);
rtfree(rt);
}
return 32 * 2;
}