NetBSD/sys/netinet6/in6_gif.c

531 lines
13 KiB
C

/* $NetBSD: in6_gif.c,v 1.95 2019/10/30 03:45:59 knakahara Exp $ */
/* $KAME: in6_gif.c,v 1.62 2001/07/29 04:27:25 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/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: in6_gif.c,v 1.95 2019/10/30 03:45:59 knakahara Exp $");
#ifdef _KERNEL_OPT
#include "opt_inet.h"
#endif
#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/ioctl.h>
#include <sys/queue.h>
#include <sys/syslog.h>
#include <sys/kernel.h>
#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#ifdef INET
#include <netinet/ip.h>
#endif
#include <netinet/ip_encap.h>
#ifdef INET6
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/ip6_private.h>
#include <netinet6/in6_gif.h>
#include <netinet6/in6_var.h>
#endif
#include <netinet6/ip6protosw.h> /* for struct ip6ctlparam */
#include <netinet/ip_ecn.h>
#include <net/if_gif.h>
static int gif_validate6(const struct ip6_hdr *, struct gif_variant *,
struct ifnet *);
int ip6_gif_hlim = GIF_HLIM;
int ip6_gif_pmtu = 0;
static const struct encapsw in6_gif_encapsw;
/*
* family - family of the packet to be encapsulate.
*/
static int
in6_gif_output(struct gif_variant *var, int family, struct mbuf *m)
{
struct rtentry *rt;
struct gif_softc *sc;
struct sockaddr_in6 *sin6_src;
struct sockaddr_in6 *sin6_dst;
struct ifnet *ifp;
struct ip6_hdr *ip6;
struct route *ro_pc;
kmutex_t *lock_pc;
int proto, error;
u_int8_t itos, otos;
KASSERT(gif_heldref_variant(var));
sin6_src = satosin6(var->gv_psrc);
sin6_dst = satosin6(var->gv_pdst);
ifp = &var->gv_softc->gif_if;
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) {
#ifdef INET
case AF_INET:
{
struct ip *ip;
proto = IPPROTO_IPV4;
if (m->m_len < sizeof(*ip)) {
m = m_pullup(m, sizeof(*ip));
if (!m)
return ENOBUFS;
}
ip = mtod(m, struct ip *);
itos = ip->ip_tos;
break;
}
#endif
#ifdef INET6
case AF_INET6:
{
proto = IPPROTO_IPV6;
if (m->m_len < 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;
}
#endif
default:
#ifdef 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);
if (m && m->m_len < sizeof(struct ip6_hdr))
m = m_pullup(m, sizeof(struct ip6_hdr));
if (m == NULL)
return ENOBUFS;
ip6 = mtod(m, struct ip6_hdr *);
ip6->ip6_flow = 0;
ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
ip6->ip6_vfc |= IPV6_VERSION;
#if 0 /* ip6->ip6_plen will be filled by ip6_output */
ip6->ip6_plen = htons((u_int16_t)m->m_pkthdr.len);
#endif
ip6->ip6_nxt = proto;
ip6->ip6_hlim = ip6_gif_hlim;
ip6->ip6_src = sin6_src->sin6_addr;
/* 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;
}
if (ifp->if_flags & IFF_LINK1)
ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
else
ip_ecn_ingress(ECN_NOCARE, &otos, &itos);
ip6->ip6_flow &= ~ntohl(0xff00000);
ip6->ip6_flow |= htonl((u_int32_t)otos << 20);
sc = ifp->if_softc;
if_tunnel_get_ro(sc->gif_ro_percpu, &ro_pc, &lock_pc);
rt = rtcache_lookup(ro_pc, var->gv_pdst);
if (rt == NULL) {
if_tunnel_put_ro(sc->gif_ro_percpu, lock_pc);
m_freem(m);
return ENETUNREACH;
}
/* If the route constitutes infinite encapsulation, punt. */
if (rt->rt_ifp == ifp) {
rtcache_unref(rt, ro_pc);
rtcache_free(ro_pc);
if_tunnel_put_ro(sc->gif_ro_percpu, lock_pc);
m_freem(m);
return ENETUNREACH; /* XXX */
}
rtcache_unref(rt, ro_pc);
#ifdef IPV6_MINMTU
int flags;
/*
* - GIF_PMTU_MINMTU
* Force fragmentation to minimum MTU to avoid path MTU discovery
* - GIF_PMTU_OUTERMTU
* Trust outer MTU is large enough to send all packets
*
* It is too painful to ask for resend of inner packet, to achieve
* path MTU discovery for encapsulated packets.
*
* See RFC4459.
*/
if (sc->gif_pmtu == GIF_PMTU_SYSDEFAULT) {
switch (ip6_gif_pmtu) {
case GIF_PMTU_MINMTU:
flags = IPV6_MINMTU;
break;
case GIF_PMTU_OUTERMTU:
flags = 0;
break;
default:
#ifdef DEBUG
log(LOG_DEBUG, "%s: ignore unexpected ip6_gif_pmtu %d\n",
__func__, ip6_gif_pmtu);
#endif
flags = IPV6_MINMTU;
break;
}
} else {
switch (sc->gif_pmtu) {
case GIF_PMTU_MINMTU:
flags = IPV6_MINMTU;
break;
case GIF_PMTU_OUTERMTU:
flags = 0;
break;
default:
#ifdef DEBUG
log(LOG_DEBUG, "%s: ignore unexpected gif_pmtu of %s %d\n",
__func__, ifp->if_xname, sc->gif_pmtu);
#endif
flags = IPV6_MINMTU;
break;
}
}
error = ip6_output(m, 0, ro_pc, flags, NULL, NULL, NULL);
#else
error = ip6_output(m, 0, ro_pc, 0, NULL, NULL, NULL);
#endif
if_tunnel_put_ro(sc->gif_ro_percpu, lock_pc);
return (error);
}
int
in6_gif_input(struct mbuf **mp, int *offp, int proto, void *eparg)
{
struct mbuf *m = *mp;
struct gif_softc *sc = eparg;
struct ifnet *gifp;
struct ip6_hdr *ip6;
int af = 0;
u_int32_t otos;
KASSERT(sc != NULL);
ip6 = mtod(m, struct ip6_hdr *);
gifp = &sc->gif_if;
if ((gifp->if_flags & IFF_UP) == 0) {
m_freem(m);
IP6_STATINC(IP6_STAT_NOGIF);
return IPPROTO_DONE;
}
#ifndef GIF_ENCAPCHECK
struct psref psref_var;
struct gif_variant *var = gif_getref_variant(sc, &psref_var);
/* other CPU do delete_tunnel */
if (var->gv_psrc == NULL || var->gv_pdst == NULL) {
gif_putref_variant(var, &psref_var);
m_freem(m);
IP6_STATINC(IP6_STAT_NOGIF);
return IPPROTO_DONE;
}
struct psref psref;
struct ifnet *rcvif = m_get_rcvif_psref(m, &psref);
if (rcvif == NULL || !gif_validate6(ip6, var, rcvif)) {
m_put_rcvif_psref(rcvif, &psref);
gif_putref_variant(var, &psref_var);
m_freem(m);
IP6_STATINC(IP6_STAT_NOGIF);
return IPPROTO_DONE;
}
m_put_rcvif_psref(rcvif, &psref);
gif_putref_variant(var, &psref_var);
#endif
otos = ip6->ip6_flow;
m_adj(m, *offp);
switch (proto) {
#ifdef INET
case IPPROTO_IPV4:
{
struct ip *ip;
u_int8_t otos8;
af = AF_INET;
otos8 = (ntohl(otos) >> 20) & 0xff;
if (m->m_len < sizeof(*ip)) {
m = m_pullup(m, sizeof(*ip));
if (!m)
return IPPROTO_DONE;
}
ip = mtod(m, struct ip *);
if (gifp->if_flags & IFF_LINK1)
ip_ecn_egress(ECN_ALLOWED, &otos8, &ip->ip_tos);
else
ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos);
break;
}
#endif /* INET */
#ifdef INET6
case IPPROTO_IPV6:
{
struct ip6_hdr *ip6x;
af = AF_INET6;
if (m->m_len < sizeof(*ip6x)) {
m = m_pullup(m, sizeof(*ip6x));
if (!m)
return IPPROTO_DONE;
}
ip6x = mtod(m, struct ip6_hdr *);
if (gifp->if_flags & IFF_LINK1)
ip6_ecn_egress(ECN_ALLOWED, &otos, &ip6x->ip6_flow);
else
ip6_ecn_egress(ECN_NOCARE, &otos, &ip6x->ip6_flow);
break;
}
#endif
default:
IP6_STATINC(IP6_STAT_NOGIF);
m_freem(m);
return IPPROTO_DONE;
}
gif_input(m, af, gifp);
return IPPROTO_DONE;
}
/*
* validate outer address.
*/
static int
gif_validate6(const struct ip6_hdr *ip6, struct gif_variant *var,
struct ifnet *ifp)
{
const struct sockaddr_in6 *src, *dst;
int ret;
src = satosin6(var->gv_psrc);
dst = satosin6(var->gv_pdst);
ret = in6_tunnel_validate(ip6, &src->sin6_addr, &dst->sin6_addr);
if (ret == 0)
return 0;
/* ingress filters on outer source */
if ((var->gv_softc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) {
union {
struct sockaddr sa;
struct sockaddr_in6 sin6;
} u;
struct rtentry *rt;
/* XXX scopeid */
sockaddr_in6_init(&u.sin6, &ip6->ip6_src, 0, 0, 0);
rt = rtalloc1(&u.sa, 0);
if (rt == NULL || rt->rt_ifp != ifp) {
#if 0
char ip6buf[INET6_ADDRSTRLEN];
log(LOG_WARNING, "%s: packet from %s dropped "
"due to ingress filter\n",
if_name(&var->gv_softc->gif_if),
IN6_PRINT(ip6buf, &u.sin6.sin6_addr));
#endif
if (rt != NULL)
rt_unref(rt);
return 0;
}
rt_unref(rt);
}
return ret;
}
#ifdef GIF_ENCAPCHECK
/*
* we know that we are in IFF_UP, outer address available, and outer family
* matched the physical addr family. see gif_encapcheck().
*/
int
gif_encapcheck6(struct mbuf *m, int off, int proto, struct gif_variant *var)
{
struct ip6_hdr ip6;
struct ifnet *ifp = NULL;
int r;
struct psref psref;
m_copydata(m, 0, sizeof(ip6), (void *)&ip6);
if ((m->m_flags & M_PKTHDR) != 0)
ifp = m_get_rcvif_psref(m, &psref);
r = gif_validate6(&ip6, var, ifp);
m_put_rcvif_psref(ifp, &psref);
return r;
}
#endif
int
in6_gif_attach(struct gif_variant *var)
{
#ifndef GIF_ENCAPCHECK
struct sockaddr_in6 mask6;
memset(&mask6, 0, sizeof(mask6));
mask6.sin6_len = sizeof(struct sockaddr_in6);
mask6.sin6_addr.s6_addr32[0] = mask6.sin6_addr.s6_addr32[1] =
mask6.sin6_addr.s6_addr32[2] = mask6.sin6_addr.s6_addr32[3] = ~0;
if (!var->gv_psrc || !var->gv_pdst)
return EINVAL;
var->gv_encap_cookie6 = encap_attach(AF_INET6, -1, var->gv_psrc,
sin6tosa(&mask6), var->gv_pdst, sin6tosa(&mask6),
(const void *)&in6_gif_encapsw, var->gv_softc);
#else
var->gv_encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck,
&in6_gif_encapsw, var->gv_softc);
#endif
if (var->gv_encap_cookie6 == NULL)
return EEXIST;
var->gv_output = in6_gif_output;
return 0;
}
int
in6_gif_detach(struct gif_variant *var)
{
int error;
struct gif_softc *sc = var->gv_softc;
error = encap_detach(var->gv_encap_cookie6);
if (error == 0)
var->gv_encap_cookie6 = NULL;
if_tunnel_ro_percpu_rtcache_free(sc->gif_ro_percpu);
return error;
}
void *
in6_gif_ctlinput(int cmd, const struct sockaddr *sa, void *d, void *eparg)
{
struct gif_softc *sc = eparg;
struct gif_variant *var;
struct ip6ctlparam *ip6cp = NULL;
struct ip6_hdr *ip6;
const struct sockaddr_in6 *dst6;
struct route *ro_pc;
kmutex_t *lock_pc;
struct psref psref;
if (sa->sa_family != AF_INET6 ||
sa->sa_len != sizeof(struct sockaddr_in6))
return NULL;
if ((unsigned)cmd >= PRC_NCMDS)
return NULL;
if (cmd == PRC_HOSTDEAD)
d = NULL;
else if (inet6ctlerrmap[cmd] == 0)
return NULL;
/* if the parameter is from icmp6, decode it. */
if (d != NULL) {
ip6cp = (struct ip6ctlparam *)d;
ip6 = ip6cp->ip6c_ip6;
} else {
ip6 = NULL;
}
if (!ip6)
return NULL;
var = gif_getref_variant(sc, &psref);
if (var->gv_psrc == NULL || var->gv_pdst == NULL) {
gif_putref_variant(var, &psref);
return NULL;
}
if (var->gv_psrc->sa_family != AF_INET6) {
gif_putref_variant(var, &psref);
return NULL;
}
gif_putref_variant(var, &psref);
if_tunnel_get_ro(sc->gif_ro_percpu, &ro_pc, &lock_pc);
dst6 = satocsin6(rtcache_getdst(ro_pc));
/* XXX scope */
if (dst6 == NULL)
;
else if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst6->sin6_addr))
rtcache_free(ro_pc);
if_tunnel_put_ro(sc->gif_ro_percpu, lock_pc);
return NULL;
}
ENCAP_PR_WRAP_CTLINPUT(in6_gif_ctlinput)
#define in6_gif_ctlinput in6_gif_ctlinput_wrapper
static const struct encapsw in6_gif_encapsw = {
.encapsw6 = {
.pr_input = in6_gif_input,
.pr_ctlinput = in6_gif_ctlinput,
}
};