NetBSD/sys/netinet/in_gif.c

400 lines
9.7 KiB
C

/* $NetBSD: in_gif.c,v 1.95 2019/09/19 06:07:25 knakahara Exp $ */
/* $KAME: in_gif.c,v 1.66 2001/07/29 04:46:09 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: in_gif.c,v 1.95 2019/09/19 06:07:25 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/syslog.h>
#include <sys/kernel.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>
#ifdef INET6
#include <netinet/ip6.h>
#endif
#include <net/if_gif.h>
static int gif_validate4(const struct ip *, struct gif_variant *,
struct ifnet *);
int ip_gif_ttl = GIF_TTL;
static const struct encapsw in_gif_encapsw = {
.encapsw4 = {
.pr_input = in_gif_input,
.pr_ctlinput = NULL,
}
};
static int
in_gif_output(struct gif_variant *var, int family, struct mbuf *m)
{
struct rtentry *rt;
struct gif_softc *sc;
struct sockaddr_in *sin_src;
struct sockaddr_in *sin_dst;
struct ifnet *ifp;
struct route *ro_pc;
kmutex_t *lock_pc;
struct ip iphdr; /* capsule IP header, host byte ordered */
int proto, error;
u_int8_t tos;
KASSERT(gif_heldref_variant(var));
sin_src = satosin(var->gv_psrc);
sin_dst = satosin(var->gv_pdst);
ifp = &var->gv_softc->gif_if;
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) {
#ifdef INET
case AF_INET:
{
const struct ip *ip;
proto = IPPROTO_IPV4;
if (m->m_len < sizeof(*ip)) {
m = m_pullup(m, sizeof(*ip));
if (m == NULL)
return ENOBUFS;
}
ip = mtod(m, const struct ip *);
tos = ip->ip_tos;
break;
}
#endif /* INET */
#ifdef INET6
case AF_INET6:
{
const struct ip6_hdr *ip6;
proto = IPPROTO_IPV6;
if (m->m_len < sizeof(*ip6)) {
m = m_pullup(m, sizeof(*ip6));
if (m == NULL)
return ENOBUFS;
}
ip6 = mtod(m, const struct ip6_hdr *);
tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
break;
}
#endif /* INET6 */
default:
#ifdef DEBUG
printf("in_gif_output: warning: unknown family %d passed\n",
family);
#endif
m_freem(m);
return EAFNOSUPPORT;
}
memset(&iphdr, 0, 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 = htons(m->m_pkthdr.len + sizeof(struct ip));
if (ifp->if_flags & IFF_LINK1)
ip_ecn_ingress(ECN_ALLOWED, &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);
/* XXX Is m_pullup really necessary after M_PREPEND? */
if (m != NULL && M_UNWRITABLE(m, sizeof(struct ip)))
m = m_pullup(m, sizeof(struct ip));
if (m == NULL)
return ENOBUFS;
bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip));
sc = var->gv_softc;
if_tunnel_get_ro(sc->gif_ro_percpu, &ro_pc, &lock_pc);
if ((rt = rtcache_lookup(ro_pc, var->gv_pdst)) == 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);
error = ip_output(m, NULL, ro_pc, 0, NULL, NULL);
if_tunnel_put_ro(sc->gif_ro_percpu, lock_pc);
return (error);
}
void
in_gif_input(struct mbuf *m, int off, int proto, void *eparg)
{
struct gif_softc *sc = eparg;
struct ifnet *gifp = &sc->gif_if;
const struct ip *ip;
int af;
u_int8_t otos;
KASSERT(sc != NULL);
ip = mtod(m, const struct ip *);
gifp = &sc->gif_if;
if ((gifp->if_flags & IFF_UP) == 0) {
m_freem(m);
ip_statinc(IP_STAT_NOGIF);
return;
}
#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);
ip_statinc(IP_STAT_NOGIF);
return;
}
struct ifnet *rcvif;
struct psref psref_rcvif;
rcvif = m_get_rcvif_psref(m, &psref_rcvif);
if (!gif_validate4(ip, var, rcvif)) {
m_put_rcvif_psref(rcvif, &psref_rcvif);
gif_putref_variant(var, &psref_var);
m_freem(m);
ip_statinc(IP_STAT_NOGIF);
return;
}
m_put_rcvif_psref(rcvif, &psref_rcvif);
gif_putref_variant(var, &psref_var);
#endif
otos = ip->ip_tos;
m_adj(m, off);
switch (proto) {
#ifdef INET
case IPPROTO_IPV4:
{
struct ip *xip;
af = AF_INET;
if (M_UNWRITABLE(m, sizeof(*xip))) {
if ((m = m_pullup(m, sizeof(*xip))) == NULL)
return;
}
xip = mtod(m, struct ip *);
if (gifp->if_flags & IFF_LINK1)
ip_ecn_egress(ECN_ALLOWED, &otos, &xip->ip_tos);
else
ip_ecn_egress(ECN_NOCARE, &otos, &xip->ip_tos);
break;
}
#endif
#ifdef INET6
case IPPROTO_IPV6:
{
struct ip6_hdr *ip6;
u_int8_t itos;
af = AF_INET6;
if (M_UNWRITABLE(m, sizeof(*ip6))) {
if ((m = m_pullup(m, sizeof(*ip6))) == NULL)
return;
}
ip6 = mtod(m, struct ip6_hdr *);
itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
if (gifp->if_flags & IFF_LINK1)
ip_ecn_egress(ECN_ALLOWED, &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);
break;
}
#endif /* INET6 */
default:
ip_statinc(IP_STAT_NOGIF);
m_freem(m);
return;
}
gif_input(m, af, gifp);
return;
}
/*
* validate outer address.
*/
static int
gif_validate4(const struct ip *ip, struct gif_variant *var, struct ifnet *ifp)
{
struct sockaddr_in *src, *dst;
int ret;
src = satosin(var->gv_psrc);
dst = satosin(var->gv_pdst);
ret = in_tunnel_validate(ip, src->sin_addr, dst->sin_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_in sin;
} u;
struct rtentry *rt;
sockaddr_in_init(&u.sin, &ip->ip_src, 0);
rt = rtalloc1(&u.sa, 0);
if (rt == NULL || rt->rt_ifp != ifp) {
#if 0
log(LOG_WARNING, "%s: packet from 0x%x dropped "
"due to ingress filter\n",
if_name(&var->gv_softc->gif_if),
(u_int32_t)ntohl(u.sin.sin_addr.s_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_encapcheck4(struct mbuf *m, int off, int proto, struct gif_variant *var)
{
struct ip ip;
struct ifnet *ifp = NULL;
int r;
struct psref psref;
m_copydata(m, 0, sizeof(ip), &ip);
if ((m->m_flags & M_PKTHDR) != 0)
ifp = m_get_rcvif_psref(m, &psref);
r = gif_validate4(&ip, var, ifp);
m_put_rcvif_psref(ifp, &psref);
return r;
}
#endif
int
in_gif_attach(struct gif_variant *var)
{
#ifndef GIF_ENCAPCHECK
struct sockaddr_in mask4;
memset(&mask4, 0, sizeof(mask4));
mask4.sin_len = sizeof(struct sockaddr_in);
mask4.sin_addr.s_addr = ~0;
if (!var->gv_psrc || !var->gv_pdst)
return EINVAL;
var->gv_encap_cookie4 = encap_attach(AF_INET, -1, var->gv_psrc,
(struct sockaddr *)&mask4, var->gv_pdst, (struct sockaddr *)&mask4,
&in_gif_encapsw, var->gv_softc);
#else
var->gv_encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck,
&in_gif_encapsw, var->gv_softc);
#endif
if (var->gv_encap_cookie4 == NULL)
return EEXIST;
var->gv_output = in_gif_output;
return 0;
}
int
in_gif_detach(struct gif_variant *var)
{
int error;
struct gif_softc *sc = var->gv_softc;
error = encap_detach(var->gv_encap_cookie4);
if (error == 0)
var->gv_encap_cookie4 = NULL;
if_tunnel_ro_percpu_rtcache_free(sc->gif_ro_percpu);
return error;
}