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gems-kernel/source/THIRDPARTY/xnu/bsd/net/if_stf.c
Sam Sneed f5727805f2 add darwin/xnu functionality
2024-06-03 11:29:39 -05:00

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/*
* Copyright (c) 2000-2020 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/net/if_stf.c,v 1.1.2.6 2001/07/24 19:10:18 brooks Exp $ */
/* $KAME: if_stf.c,v 1.62 2001/06/07 22:32:16 itojun Exp $ */
/*
* Copyright (C) 2000 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.
*/
/*
* NOTICE: This file was modified by SPARTA, Inc. in 2006 to introduce
* support for mandatory and extensible security protections. This notice
* is included in support of clause 2.2 (b) of the Apple Public License,
* Version 2.0.
*/
/*
* 6to4 interface, based on RFC3056.
*
* 6to4 interface is NOT capable of link-layer (I mean, IPv4) multicasting.
* There is no address mapping defined from IPv6 multicast address to IPv4
* address. Therefore, we do not have IFF_MULTICAST on the interface.
*
* Due to the lack of address mapping for link-local addresses, we cannot
* throw packets toward link-local addresses (fe80::x). Also, we cannot throw
* packets to link-local multicast addresses (ff02::x).
*
* Here are interesting symptoms due to the lack of link-local address:
*
* Unicast routing exchange:
* - RIPng: Impossible. Uses link-local multicast packet toward ff02::9,
* and link-local addresses as nexthop.
* - OSPFv6: Impossible. OSPFv6 assumes that there's link-local address
* assigned to the link, and makes use of them. Also, HELLO packets use
* link-local multicast addresses (ff02::5 and ff02::6).
* - BGP4+: Maybe. You can only use global address as nexthop, and global
* address as TCP endpoint address.
*
* Multicast routing protocols:
* - PIM: Hello packet cannot be used to discover adjacent PIM routers.
* Adjacent PIM routers must be configured manually (is it really spec-wise
* correct thing to do?).
*
* ICMPv6:
* - Redirects cannot be used due to the lack of link-local address.
*
* stf interface does not have, and will not need, a link-local address.
* It seems to have no real benefit and does not help the above symptoms much.
* Even if we assign link-locals to interface, we cannot really
* use link-local unicast/multicast on top of 6to4 cloud (since there's no
* encapsulation defined for link-local address), and the above analysis does
* not change. RFC3056 does not mandate the assignment of link-local address
* either.
*
* 6to4 interface has security issues. Refer to
* http://playground.iijlab.net/i-d/draft-itojun-ipv6-transition-abuse-00.txt
* for details. The code tries to filter out some of malicious packets.
* Note that there is no way to be 100% secure.
*/
#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/protosw.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <sys/malloc.h>
#include <kern/locks.h>
#include <net/if.h>
#include <net/route.h>
#include <net/if_types.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/in_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/in6_var.h>
#include <netinet/ip_ecn.h>
#include <netinet/ip_encap.h>
#include <net/kpi_interface.h>
#include <net/kpi_protocol.h>
#include <net/net_osdep.h>
#include <net/bpf.h>
#include <net/sockaddr_utils.h>
#define GET_V4(x) ((const struct in_addr *)(const void *)(&(x)->s6_addr16[1]))
static LCK_GRP_DECLARE(stf_mtx_grp, "stf");
struct stf_softc {
ifnet_t sc_if; /* common area */
u_int32_t sc_protocol_family; /* dlil protocol attached */
union {
struct route __sc_ro4;
struct route_in6 __sc_ro6; /* just for safety */
} __sc_ro46;
#define sc_ro __sc_ro46.__sc_ro4
decl_lck_mtx_data(, sc_ro_mtx);
const struct encaptab *encap_cookie;
bpf_tap_mode tap_mode;
bpf_packet_func tap_callback;
};
void stfattach(void);
static int ip_stf_ttl = 40;
static void in_stf_input(struct mbuf *, int);
static struct protosw in_stf_protosw =
{
.pr_type = SOCK_RAW,
.pr_protocol = IPPROTO_IPV6,
.pr_flags = PR_ATOMIC | PR_ADDR,
.pr_input = in_stf_input,
.pr_ctloutput = rip_ctloutput,
.pr_usrreqs = &rip_usrreqs,
.pr_unlock = rip_unlock,
};
static int stf_encapcheck(const struct mbuf *, int, int, void *);
static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *);
int stf_pre_output(struct ifnet *, protocol_family_t, struct mbuf **,
const struct sockaddr *, void *, char *, char *);
static int stf_checkaddr4(struct stf_softc *, const struct in_addr *,
struct ifnet *);
static int stf_checkaddr6(struct stf_softc *, struct in6_addr *,
struct ifnet *);
static void stf_rtrequest(int, struct rtentry *, struct sockaddr *);
static errno_t stf_ioctl(ifnet_t ifp, u_long cmd, void *data);
static errno_t stf_output(ifnet_t ifp, mbuf_t m);
/*
* gif_input is the input handler for IP and IPv6 attached to gif
*/
static errno_t
stf_media_input(
__unused ifnet_t ifp,
protocol_family_t protocol_family,
mbuf_t m,
__unused char *frame_header)
{
if (proto_input(protocol_family, m) != 0) {
m_freem(m);
}
return 0;
}
static errno_t
stf_add_proto(
ifnet_t ifp,
protocol_family_t protocol_family,
__unused const struct ifnet_demux_desc *demux_array,
__unused u_int32_t demux_count)
{
/* Only one protocol may be attached at a time */
struct stf_softc* stf = ifnet_softc(ifp);
if (stf->sc_protocol_family == 0) {
stf->sc_protocol_family = protocol_family;
} else {
printf("stf_add_proto: stf already has a proto\n");
return EBUSY;
}
return 0;
}
static errno_t
stf_del_proto(
ifnet_t ifp,
protocol_family_t protocol_family)
{
if (((struct stf_softc*)ifnet_softc(ifp))->sc_protocol_family == protocol_family) {
((struct stf_softc*)ifnet_softc(ifp))->sc_protocol_family = 0;
}
return 0;
}
static errno_t
stf_attach_inet6(
ifnet_t ifp,
protocol_family_t protocol_family)
{
struct ifnet_attach_proto_param reg;
errno_t stat;
if (protocol_family != PF_INET6) {
return EPROTONOSUPPORT;
}
bzero(&reg, sizeof(reg));
reg.input = stf_media_input;
reg.pre_output = stf_pre_output;
stat = ifnet_attach_protocol(ifp, protocol_family, &reg);
if (stat && stat != EEXIST) {
printf("stf_attach_proto_family can't attach interface fam=%d\n",
protocol_family);
}
return stat;
}
static errno_t
stf_demux(
ifnet_t ifp,
__unused mbuf_t m,
__unused char *frame_ptr,
protocol_family_t *protocol_family)
{
struct stf_softc* stf = ifnet_softc(ifp);
*protocol_family = stf->sc_protocol_family;
return 0;
}
static errno_t
stf_set_bpf_tap(
ifnet_t ifp,
bpf_tap_mode mode,
bpf_packet_func callback)
{
struct stf_softc *sc = ifnet_softc(ifp);
sc->tap_mode = mode;
sc->tap_callback = callback;
return 0;
}
void
stfattach(void)
{
struct stf_softc *sc;
int error;
const struct encaptab *p;
struct ifnet_init_eparams stf_init;
error = proto_register_plumber(PF_INET6, APPLE_IF_FAM_STF,
stf_attach_inet6, NULL);
if (error != 0) {
printf("proto_register_plumber failed for AF_INET6 error=%d\n", error);
}
sc = kalloc_type(struct stf_softc, Z_WAITOK_ZERO_NOFAIL);
lck_mtx_init(&sc->sc_ro_mtx, &stf_mtx_grp, LCK_ATTR_NULL);
p = encap_attach_func(AF_INET, IPPROTO_IPV6, stf_encapcheck,
&in_stf_protosw, sc);
if (p == NULL) {
printf("sftattach encap_attach_func failed\n");
goto free_sc;
}
sc->encap_cookie = p;
bzero(&stf_init, sizeof(stf_init));
stf_init.ver = IFNET_INIT_CURRENT_VERSION;
stf_init.len = sizeof(stf_init);
stf_init.flags = IFNET_INIT_LEGACY;
stf_init.name = "stf";
stf_init.unit = 0;
stf_init.type = IFT_STF;
stf_init.family = IFNET_FAMILY_STF;
stf_init.output = stf_output;
stf_init.demux = stf_demux;
stf_init.add_proto = stf_add_proto;
stf_init.del_proto = stf_del_proto;
stf_init.softc = sc;
stf_init.ioctl = stf_ioctl;
stf_init.set_bpf_tap = stf_set_bpf_tap;
error = ifnet_allocate_extended(&stf_init, &sc->sc_if);
if (error != 0) {
printf("stfattach, ifnet_allocate failed - %d\n", error);
encap_detach(sc->encap_cookie);
goto free_sc;
}
ifnet_set_mtu(sc->sc_if, IPV6_MMTU);
ifnet_set_flags(sc->sc_if, 0, 0xffff); /* clear all flags */
#if 0
/* turn off ingress filter */
ifnet_set_flags(sc->sc_if, IFF_LINK2, IFF_LINK2);
#endif
error = ifnet_attach(sc->sc_if, NULL);
if (error != 0) {
printf("stfattach: ifnet_attach returned error=%d\n", error);
encap_detach(sc->encap_cookie);
ifnet_release(sc->sc_if);
goto free_sc;
}
bpfattach(sc->sc_if, DLT_NULL, sizeof(u_int));
return;
free_sc:
lck_mtx_destroy(&sc->sc_ro_mtx, &stf_mtx_grp);
kfree_type(struct stf_softc, sc);
}
static int
stf_encapcheck(
const struct mbuf *m,
__unused int off,
int proto,
void *arg)
{
struct ip ip;
struct in6_ifaddr *ia6;
struct stf_softc *sc;
struct in_addr a, b;
sc = (struct stf_softc *)arg;
if (sc == NULL) {
return 0;
}
if ((ifnet_flags(sc->sc_if) & IFF_UP) == 0) {
return 0;
}
/* IFF_LINK0 means "no decapsulation" */
if ((ifnet_flags(sc->sc_if) & IFF_LINK0) != 0) {
return 0;
}
if (proto != IPPROTO_IPV6) {
return 0;
}
mbuf_copydata((struct mbuf *)(size_t)m, 0, sizeof(ip), &ip);
if (ip.ip_v != 4) {
return 0;
}
ia6 = stf_getsrcifa6(sc->sc_if);
if (ia6 == NULL) {
return 0;
}
/*
* check if IPv4 dst matches the IPv4 address derived from the
* local 6to4 address.
* success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:...
*/
IFA_LOCK(&ia6->ia_ifa);
if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst,
sizeof(ip.ip_dst)) != 0) {
IFA_UNLOCK(&ia6->ia_ifa);
ifa_remref(&ia6->ia_ifa);
return 0;
}
/*
* check if IPv4 src matches the IPv4 address derived from the
* local 6to4 address masked by prefixmask.
* success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24
* fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24
*/
bzero(&a, sizeof(a));
a.s_addr = GET_V4(&ia6->ia_addr.sin6_addr)->s_addr;
a.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr;
b = ip.ip_src;
b.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr;
if (a.s_addr != b.s_addr) {
IFA_UNLOCK(&ia6->ia_ifa);
ifa_remref(&ia6->ia_ifa);
return 0;
}
/* stf interface makes single side match only */
IFA_UNLOCK(&ia6->ia_ifa);
ifa_remref(&ia6->ia_ifa);
return 32;
}
static struct in6_ifaddr *
stf_getsrcifa6(struct ifnet *ifp)
{
struct ifaddr *ia;
struct in_ifaddr *ia4;
struct sockaddr_in6 *sin6;
struct in_addr in;
ifnet_lock_shared(ifp);
for (ia = ifp->if_addrlist.tqh_first; ia; ia = ia->ifa_list.tqe_next) {
IFA_LOCK(ia);
if (ia->ifa_addr == NULL) {
IFA_UNLOCK(ia);
continue;
}
if (ia->ifa_addr->sa_family != AF_INET6) {
IFA_UNLOCK(ia);
continue;
}
sin6 = SIN6(ia->ifa_addr);
if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) {
IFA_UNLOCK(ia);
continue;
}
bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in));
IFA_UNLOCK(ia);
lck_rw_lock_shared(&in_ifaddr_rwlock);
for (ia4 = TAILQ_FIRST(&in_ifaddrhead);
ia4;
ia4 = TAILQ_NEXT(ia4, ia_link)) {
IFA_LOCK(&ia4->ia_ifa);
if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) {
IFA_UNLOCK(&ia4->ia_ifa);
break;
}
IFA_UNLOCK(&ia4->ia_ifa);
}
lck_rw_done(&in_ifaddr_rwlock);
if (ia4 == NULL) {
continue;
}
ifa_addref(ia); /* for caller */
ifnet_lock_done(ifp);
return (struct in6_ifaddr *)ia;
}
ifnet_lock_done(ifp);
return NULL;
}
int
stf_pre_output(
struct ifnet *ifp,
__unused protocol_family_t protocol_family,
struct mbuf **m0,
const struct sockaddr *dst,
__unused void *route,
__unused char *desk_linkaddr,
__unused char *frame_type)
{
struct mbuf *m = *m0;
struct stf_softc *sc;
const struct sockaddr_in6 *dst6;
const struct in_addr *in4;
u_int8_t tos;
struct ip *ip;
struct ip6_hdr *ip6;
struct in6_ifaddr *ia6;
struct sockaddr_in *dst4;
struct ip_out_args ipoa;
errno_t result = 0;
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;
sc = ifnet_softc(ifp);
dst6 = SIN6(dst);
/* just in case */
if ((ifnet_flags(ifp) & IFF_UP) == 0) {
printf("stf: IFF_DOWN\n");
return ENETDOWN;
}
/*
* If we don't have an ip4 address that match my inner ip6 address,
* we shouldn't generate output. Without this check, we'll end up
* using wrong IPv4 source.
*/
ia6 = stf_getsrcifa6(ifp);
if (ia6 == NULL) {
return ENETDOWN;
}
if (mbuf_len(m) < sizeof(*ip6)) {
m = m_pullup(m, sizeof(*ip6));
if (!m) {
*m0 = NULL; /* makes sure this won't be double freed */
ifa_remref(&ia6->ia_ifa);
return ENOBUFS;
}
*m0 = m;
}
ip6 = mtod(m, struct ip6_hdr *);
tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
/*
* Pickup the right outer dst addr from the list of candidates.
* ip6_dst has priority as it may be able to give us shorter IPv4 hops.
*/
if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) {
in4 = GET_V4(&ip6->ip6_dst);
} else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) {
in4 = GET_V4(&dst6->sin6_addr);
} else {
ifa_remref(&ia6->ia_ifa);
return ENETUNREACH;
}
if (ifp->if_bpf) {
/* We need to prepend the address family as a four byte field. */
u_int32_t af = AF_INET6;
bpf_tap_out(ifp, 0, m, &af, sizeof(af));
}
M_PREPEND(m, sizeof(struct ip), M_DONTWAIT, 1);
if (m && mbuf_len(m) < sizeof(struct ip)) {
m = m_pullup(m, sizeof(struct ip));
}
if (m == NULL) {
*m0 = NULL;
ifa_remref(&ia6->ia_ifa);
return ENOBUFS;
}
*m0 = m;
ip = mtod(m, struct ip *);
bzero(ip, sizeof(*ip));
IFA_LOCK_SPIN(&ia6->ia_ifa);
bcopy(GET_V4(&(SIN6(&ia6->ia_addr))->sin6_addr),
&ip->ip_src, sizeof(ip->ip_src));
IFA_UNLOCK(&ia6->ia_ifa);
bcopy(in4, &ip->ip_dst, sizeof(ip->ip_dst));
ip->ip_p = IPPROTO_IPV6;
ip->ip_ttl = ip_stf_ttl;
ip->ip_len = m->m_pkthdr.len; /*host order*/
if (ifp->if_flags & IFF_LINK1) {
ip_ecn_ingress(ECN_NORMAL, &ip->ip_tos, &tos);
} else {
ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos);
}
lck_mtx_lock(&sc->sc_ro_mtx);
dst4 = SIN(&sc->sc_ro.ro_dst);
if (ROUTE_UNUSABLE(&sc->sc_ro) || dst4->sin_family != AF_INET ||
bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) {
ROUTE_RELEASE(&sc->sc_ro);
/* cache route doesn't match: always the case during the first use */
dst4->sin_family = AF_INET;
dst4->sin_len = sizeof(struct sockaddr_in);
bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr));
}
result = ip_output(m, NULL, &sc->sc_ro, IP_OUTARGS, NULL, &ipoa);
lck_mtx_unlock(&sc->sc_ro_mtx);
/* Assumption: ip_output will free mbuf on errors */
/* All the output processing is done here, don't let stf_output be called */
if (result == 0) {
result = EJUSTRETURN;
}
*m0 = NULL;
ifa_remref(&ia6->ia_ifa);
return result;
}
static errno_t
stf_output(
__unused ifnet_t ifp,
__unused mbuf_t m)
{
/* All processing is done in stf_pre_output
* this shouldn't be called as the pre_output returns "EJUSTRETURN"
*/
return 0;
}
static int
stf_checkaddr4(
struct stf_softc *sc,
const struct in_addr *in,
struct ifnet *inifp) /* incoming interface */
{
struct in_ifaddr *ia4;
/*
* reject packets with the following address:
* 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8
*/
if (IN_MULTICAST(ntohl(in->s_addr))) {
return -1;
}
switch ((ntohl(in->s_addr) & 0xff000000) >> 24) {
case 0: case 127: case 255:
return -1;
}
/*
* reject packets with broadcast
*/
lck_rw_lock_shared(&in_ifaddr_rwlock);
for (ia4 = TAILQ_FIRST(&in_ifaddrhead);
ia4;
ia4 = TAILQ_NEXT(ia4, ia_link)) {
IFA_LOCK(&ia4->ia_ifa);
if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) {
IFA_UNLOCK(&ia4->ia_ifa);
continue;
}
if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) {
IFA_UNLOCK(&ia4->ia_ifa);
lck_rw_done(&in_ifaddr_rwlock);
return -1;
}
IFA_UNLOCK(&ia4->ia_ifa);
}
lck_rw_done(&in_ifaddr_rwlock);
/*
* perform ingress filter
*/
if (sc && (ifnet_flags(sc->sc_if) & IFF_LINK2) == 0 && inifp) {
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 = *in;
rt = rtalloc1(SA(&sin), 0, 0);
if (rt != NULL) {
RT_LOCK(rt);
}
if (rt == NULL || rt->rt_ifp != inifp) {
#if 1
log(LOG_WARNING, "%s: packet from 0x%x dropped "
"due to ingress filter\n", if_name(sc->sc_if),
(u_int32_t)ntohl(sin.sin_addr.s_addr));
#endif
if (rt != NULL) {
RT_UNLOCK(rt);
rtfree(rt);
}
return -1;
}
RT_UNLOCK(rt);
rtfree(rt);
}
return 0;
}
static int
stf_checkaddr6(
struct stf_softc *sc,
struct in6_addr *in6,
struct ifnet *inifp) /* incoming interface */
{
/*
* check 6to4 addresses
*/
if (IN6_IS_ADDR_6TO4(in6)) {
return stf_checkaddr4(sc, GET_V4(in6), inifp);
}
/*
* reject anything that look suspicious. the test is implemented
* in ip6_input too, but we check here as well to
* (1) reject bad packets earlier, and
* (2) to be safe against future ip6_input change.
*/
if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) {
return -1;
}
return 0;
}
static void
in_stf_input(
struct mbuf *m,
int off)
{
struct stf_softc *sc;
struct ip *ip;
struct ip6_hdr ip6;
u_int8_t otos, itos;
int proto;
struct ifnet *ifp;
struct ifnet_stat_increment_param stats;
ip = mtod(m, struct ip *);
proto = ip->ip_p;
if (proto != IPPROTO_IPV6) {
m_freem(m);
return;
}
ip = mtod(m, struct ip *);
sc = (struct stf_softc *)encap_getarg(m);
if (sc == NULL || (ifnet_flags(sc->sc_if) & IFF_UP) == 0) {
m_freem(m);
return;
}
ifp = sc->sc_if;
/*
* perform sanity check against outer src/dst.
* for source, perform ingress filter as well.
*/
if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 ||
stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) {
m_freem(m);
return;
}
otos = ip->ip_tos;
if (mbuf_copydata(m, off, sizeof(ip6), &ip6)) {
m_freem(m);
return;
}
/*
* perform sanity check against inner src/dst.
* for source, perform ingress filter as well.
*/
if (stf_checkaddr6(sc, &ip6.ip6_dst, NULL) < 0 ||
stf_checkaddr6(sc, &ip6.ip6_src, m->m_pkthdr.rcvif) < 0) {
m_freem(m);
return;
}
itos = (ntohl(ip6.ip6_flow) >> 20) & 0xff;
if ((ifnet_flags(ifp) & IFF_LINK1) != 0) {
ip_ecn_egress(ECN_NORMAL, &otos, &itos);
} else {
ip_ecn_egress(ECN_NOCARE, &otos, &itos);
}
ip6.ip6_flow &= ~htonl(0xff << 20);
ip6.ip6_flow |= htonl((u_int32_t)itos << 20);
m->m_pkthdr.rcvif = ifp;
mbuf_pkthdr_setheader(m, mbuf_data(m));
mbuf_adj(m, off);
if (ifp->if_bpf) {
/* We need to prepend the address family as a four byte field. */
u_int32_t af = AF_INET6;
bpf_tap_in(ifp, 0, m, &af, sizeof(af));
}
/*
* Put the packet to the network layer input queue according to the
* specified address family.
* See net/if_gif.c for possible issues with packet processing
* reorder due to extra queueing.
*/
bzero(&stats, sizeof(stats));
stats.packets_in = 1;
stats.bytes_in = mbuf_pkthdr_len(m);
mbuf_pkthdr_setrcvif(m, ifp);
ifnet_input(ifp, m, &stats);
return;
}
static void
stf_rtrequest(
__unused int cmd,
struct rtentry *rt,
__unused struct sockaddr *sa)
{
if (rt != NULL) {
RT_LOCK_ASSERT_HELD(rt);
rt->rt_rmx.rmx_mtu = IPV6_MMTU;
}
}
static errno_t
stf_ioctl(
ifnet_t ifp,
u_long cmd,
void *data)
{
struct ifaddr *ifa;
struct ifreq *ifr;
struct sockaddr_in6 *sin6;
int error;
error = 0;
switch (cmd) {
case SIOCSIFADDR:
ifa = (struct ifaddr *)data;
if (ifa == NULL) {
error = EAFNOSUPPORT;
break;
}
IFA_LOCK(ifa);
if (ifa->ifa_addr->sa_family != AF_INET6) {
IFA_UNLOCK(ifa);
error = EAFNOSUPPORT;
break;
}
sin6 = SIN6(ifa->ifa_addr);
if (IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) {
if (!(ifnet_flags( ifp ) & IFF_UP)) {
/* do this only if the interface is not already up */
ifa->ifa_rtrequest = stf_rtrequest;
IFA_UNLOCK(ifa);
ifnet_set_flags(ifp, IFF_UP, IFF_UP);
} else {
IFA_UNLOCK(ifa);
}
} else {
IFA_UNLOCK(ifa);
error = EINVAL;
}
IFA_LOCK_ASSERT_NOTHELD(ifa);
break;
case SIOCADDMULTI:
case SIOCDELMULTI:
ifr = (struct ifreq *)data;
if (ifr && ifr->ifr_addr.sa_family == AF_INET6) {
;
} else {
error = EAFNOSUPPORT;
}
break;
default:
error = EOPNOTSUPP;
break;
}
return error;
}
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