/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* Copyright (c) 2018 Andrey V. Elsukov <ae@FreeBSD.org>
* 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.
*
* $KAME: if_gif.c,v 1.87 2001/10/19 08:50:27 itojun Exp $
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/rmlock.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sx.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/conf.h>
#include <machine/cpu.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_private.h>
#include <net/if_clone.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/route.h>
#include <net/bpf.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_ecn.h>
#ifdef INET
#include <netinet/in_var.h>
#include <netinet/ip_var.h>
#endif /* INET */
#ifdef INET6
#ifndef INET
#include <netinet/in.h>
#endif
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_ecn.h>
#include <netinet6/ip6_var.h>
#endif /* INET6 */
#include <netinet/ip_encap.h>
#include <net/ethernet.h>
#include <net/if_bridgevar.h>
#include <net/if_gif.h>
#include <security/mac/mac_framework.h>
static const char gifname[] = "gif";
MALLOC_DEFINE(M_GIF, "gif", "Generic Tunnel Interface");
static struct sx gif_ioctl_sx;
SX_SYSINIT(gif_ioctl_sx, &gif_ioctl_sx, "gif_ioctl");
void (*ng_gif_input_p)(struct ifnet *ifp, struct mbuf **mp, int af);
void (*ng_gif_input_orphan_p)(struct ifnet *ifp, struct mbuf *m, int af);
void (*ng_gif_attach_p)(struct ifnet *ifp);
void (*ng_gif_detach_p)(struct ifnet *ifp);
#ifdef VIMAGE
static void gif_reassign(struct ifnet *, struct vnet *, char *);
#endif
static void gif_delete_tunnel(struct gif_softc *);
static int gif_ioctl(struct ifnet *, u_long, caddr_t);
static int gif_transmit(struct ifnet *, struct mbuf *);
static void gif_qflush(struct ifnet *);
static int gif_clone_create(struct if_clone *, int, caddr_t);
static void gif_clone_destroy(struct ifnet *);
VNET_DEFINE_STATIC(struct if_clone *, gif_cloner);
#define V_gif_cloner VNET(gif_cloner)
SYSCTL_DECL(_net_link);
static SYSCTL_NODE(_net_link, IFT_GIF, gif, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Generic Tunnel Interface");
#ifndef MAX_GIF_NEST
/*
* This macro controls the default upper limitation on nesting of gif tunnels.
* Since, setting a large value to this macro with a careless configuration
* may introduce system crash, we don't allow any nestings by default.
* If you need to configure nested gif tunnels, you can define this macro
* in your kernel configuration file. However, if you do so, please be
* careful to configure the tunnels so that it won't make a loop.
*/
#define MAX_GIF_NEST 1
#endif
VNET_DEFINE_STATIC(int, max_gif_nesting) = MAX_GIF_NEST;
#define V_max_gif_nesting VNET(max_gif_nesting)
SYSCTL_INT(_net_link_gif, OID_AUTO, max_nesting, CTLFLAG_VNET | CTLFLAG_RW,
&VNET_NAME(max_gif_nesting), 0, "Max nested tunnels");
static int
gif_clone_create(struct if_clone *ifc, int unit, caddr_t params)
{
struct gif_softc *sc;
sc = malloc(sizeof(struct gif_softc), M_GIF, M_WAITOK | M_ZERO);
sc->gif_fibnum = curthread->td_proc->p_fibnum;
GIF2IFP(sc) = if_alloc(IFT_GIF);
GIF2IFP(sc)->if_softc = sc;
if_initname(GIF2IFP(sc), gifname, unit);
GIF2IFP(sc)->if_addrlen = 0;
GIF2IFP(sc)->if_mtu = GIF_MTU;
GIF2IFP(sc)->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
GIF2IFP(sc)->if_ioctl = gif_ioctl;
GIF2IFP(sc)->if_transmit = gif_transmit;
GIF2IFP(sc)->if_qflush = gif_qflush;
GIF2IFP(sc)->if_output = gif_output;
#ifdef VIMAGE
GIF2IFP(sc)->if_reassign = gif_reassign;
#endif
GIF2IFP(sc)->if_capabilities |= IFCAP_LINKSTATE;
GIF2IFP(sc)->if_capenable |= IFCAP_LINKSTATE;
if_attach(GIF2IFP(sc));
bpfattach(GIF2IFP(sc), DLT_NULL, sizeof(u_int32_t));
if (ng_gif_attach_p != NULL)
(*ng_gif_attach_p)(GIF2IFP(sc));
return (0);
}
#ifdef VIMAGE
static void
gif_reassign(struct ifnet *ifp, struct vnet *new_vnet __unused,
char *unused __unused)
{
struct gif_softc *sc;
sx_xlock(&gif_ioctl_sx);
sc = ifp->if_softc;
if (sc != NULL)
gif_delete_tunnel(sc);
sx_xunlock(&gif_ioctl_sx);
}
#endif /* VIMAGE */
static void
gif_clone_destroy(struct ifnet *ifp)
{
struct gif_softc *sc;
sx_xlock(&gif_ioctl_sx);
sc = ifp->if_softc;
gif_delete_tunnel(sc);
if (ng_gif_detach_p != NULL)
(*ng_gif_detach_p)(ifp);
bpfdetach(ifp);
if_detach(ifp);
ifp->if_softc = NULL;
sx_xunlock(&gif_ioctl_sx);
GIF_WAIT();
if_free(ifp);
free(sc, M_GIF);
}
static void
vnet_gif_init(const void *unused __unused)
{
V_gif_cloner = if_clone_simple(gifname, gif_clone_create,
gif_clone_destroy, 0);
#ifdef INET
in_gif_init();
#endif
#ifdef INET6
in6_gif_init();
#endif
}
VNET_SYSINIT(vnet_gif_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
vnet_gif_init, NULL);
static void
vnet_gif_uninit(const void *unused __unused)
{
if_clone_detach(V_gif_cloner);
#ifdef INET
in_gif_uninit();
#endif
#ifdef INET6
in6_gif_uninit();
#endif
}
VNET_SYSUNINIT(vnet_gif_uninit, SI_SUB_PSEUDO, SI_ORDER_ANY,
vnet_gif_uninit, NULL);
static int
gifmodevent(module_t mod, int type, void *data)
{
switch (type) {
case MOD_LOAD:
case MOD_UNLOAD:
break;
default:
return (EOPNOTSUPP);
}
return (0);
}
static moduledata_t gif_mod = {
"if_gif",
gifmodevent,
0
};
DECLARE_MODULE(if_gif, gif_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
MODULE_VERSION(if_gif, 1);
struct gif_list *
gif_hashinit(void)
{
struct gif_list *hash;
int i;
hash = malloc(sizeof(struct gif_list) * GIF_HASH_SIZE,
M_GIF, M_WAITOK);
for (i = 0; i < GIF_HASH_SIZE; i++)
CK_LIST_INIT(&hash[i]);
return (hash);
}
void
gif_hashdestroy(struct gif_list *hash)
{
free(hash, M_GIF);
}
#define MTAG_GIF 1080679712
static int
gif_transmit(struct ifnet *ifp, struct mbuf *m)
{
struct gif_softc *sc;
struct etherip_header *eth;
#ifdef INET
struct ip *ip;
#endif
#ifdef INET6
struct ip6_hdr *ip6;
uint32_t t;
#endif
uint32_t af;
uint8_t proto, ecn;
int error;
NET_EPOCH_ASSERT();
#ifdef MAC
error = mac_ifnet_check_transmit(ifp, m);
if (error) {
m_freem(m);
goto err;
}
#endif
error = ENETDOWN;
sc = ifp->if_softc;
if ((ifp->if_flags & IFF_MONITOR) != 0 ||
(ifp->if_flags & IFF_UP) == 0 ||
(ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
sc->gif_family == 0 ||
(error = if_tunnel_check_nesting(ifp, m, MTAG_GIF,
V_max_gif_nesting)) != 0) {
m_freem(m);
goto err;
}
/* Now pull back the af that we stashed in the csum_data. */
if (ifp->if_bridge)
af = AF_LINK;
else
af = m->m_pkthdr.csum_data;
m->m_flags &= ~(M_BCAST|M_MCAST);
M_SETFIB(m, sc->gif_fibnum);
BPF_MTAP2(ifp, &af, sizeof(af), m);
if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
if_inc_counter(ifp, IFCOUNTER_OBYTES, m->m_pkthdr.len);
/* inner AF-specific encapsulation */
ecn = 0;
switch (af) {
#ifdef INET
case AF_INET:
proto = IPPROTO_IPV4;
if (m->m_len < sizeof(struct ip))
m = m_pullup(m, sizeof(struct ip));
if (m == NULL) {
error = ENOBUFS;
goto err;
}
ip = mtod(m, struct ip *);
ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED:
ECN_NOCARE, &ecn, &ip->ip_tos);
break;
#endif
#ifdef INET6
case AF_INET6:
proto = IPPROTO_IPV6;
if (m->m_len < sizeof(struct ip6_hdr))
m = m_pullup(m, sizeof(struct ip6_hdr));
if (m == NULL) {
error = ENOBUFS;
goto err;
}
t = 0;
ip6 = mtod(m, struct ip6_hdr *);
ip6_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED:
ECN_NOCARE, &t, &ip6->ip6_flow);
ecn = (ntohl(t) >> 20) & 0xff;
break;
#endif
case AF_LINK:
proto = IPPROTO_ETHERIP;
M_PREPEND(m, sizeof(struct etherip_header), M_NOWAIT);
if (m == NULL) {
error = ENOBUFS;
goto err;
}
eth = mtod(m, struct etherip_header *);
eth->eip_resvh = 0;
eth->eip_ver = ETHERIP_VERSION;
eth->eip_resvl = 0;
break;
default:
error = EAFNOSUPPORT;
m_freem(m);
goto err;
}
/* XXX should we check if our outer source is legal? */
/* dispatch to output logic based on outer AF */
switch (sc->gif_family) {
#ifdef INET
case AF_INET:
error = in_gif_output(ifp, m, proto, ecn);
break;
#endif
#ifdef INET6
case AF_INET6:
error = in6_gif_output(ifp, m, proto, ecn);
break;
#endif
default:
m_freem(m);
}
err:
if (error)
if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
return (error);
}
static void
gif_qflush(struct ifnet *ifp __unused)
{
}
int
gif_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
struct route *ro)
{
uint32_t af;
if (dst->sa_family == AF_UNSPEC)
bcopy(dst->sa_data, &af, sizeof(af));
else
af = RO_GET_FAMILY(ro, dst);
/*
* Now save the af in the inbound pkt csum data, this is a cheat since
* we are using the inbound csum_data field to carry the af over to
* the gif_transmit() routine, avoiding using yet another mtag.
*/
m->m_pkthdr.csum_data = af;
return (ifp->if_transmit(ifp, m));
}
void
gif_input(struct mbuf *m, struct ifnet *ifp, int proto, uint8_t ecn)
{
struct etherip_header *eip;
#ifdef INET
struct ip *ip;
#endif
#ifdef INET6
struct ip6_hdr *ip6;
uint32_t t;
#endif
struct ether_header *eh;
struct ifnet *oldifp;
int isr, n, af;
NET_EPOCH_ASSERT();
if (ifp == NULL) {
/* just in case */
m_freem(m);
return;
}
m->m_pkthdr.rcvif = ifp;
m_clrprotoflags(m);
switch (proto) {
#ifdef INET
case IPPROTO_IPV4:
af = AF_INET;
if (m->m_len < sizeof(struct ip))
m = m_pullup(m, sizeof(struct ip));
if (m == NULL)
goto drop;
ip = mtod(m, struct ip *);
if (ip_ecn_egress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED:
ECN_NOCARE, &ecn, &ip->ip_tos) == 0) {
m_freem(m);
goto drop;
}
break;
#endif
#ifdef INET6
case IPPROTO_IPV6:
af = AF_INET6;
if (m->m_len < sizeof(struct ip6_hdr))
m = m_pullup(m, sizeof(struct ip6_hdr));
if (m == NULL)
goto drop;
t = htonl((uint32_t)ecn << 20);
ip6 = mtod(m, struct ip6_hdr *);
if (ip6_ecn_egress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED:
ECN_NOCARE, &t, &ip6->ip6_flow) == 0) {
m_freem(m);
goto drop;
}
break;
#endif
case IPPROTO_ETHERIP:
af = AF_LINK;
break;
default:
m_freem(m);
goto drop;
}
#ifdef MAC
mac_ifnet_create_mbuf(ifp, m);
#endif
if (bpf_peers_present(ifp->if_bpf)) {
uint32_t af1 = af;
bpf_mtap2(ifp->if_bpf, &af1, sizeof(af1), m);
}
if ((ifp->if_flags & IFF_MONITOR) != 0) {
if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
m_freem(m);
return;
}
if (ng_gif_input_p != NULL) {
(*ng_gif_input_p)(ifp, &m, af);
if (m == NULL)
goto drop;
}
/*
* Put the packet to the network layer input queue according to the
* specified address family.
* Note: older versions of gif_input directly called network layer
* input functions, e.g. ip6_input, here. We changed the policy to
* prevent too many recursive calls of such input functions, which
* might cause kernel panic. But the change may introduce another
* problem; if the input queue is full, packets are discarded.
* The kernel stack overflow really happened, and we believed
* queue-full rarely occurs, so we changed the policy.
*/
switch (af) {
#ifdef INET
case AF_INET:
isr = NETISR_IP;
break;
#endif
#ifdef INET6
case AF_INET6:
isr = NETISR_IPV6;
break;
#endif
case AF_LINK:
n = sizeof(struct etherip_header) +
sizeof(struct ether_header);
if (n > m->m_len)
m = m_pullup(m, n);
if (m == NULL)
goto drop;
eip = mtod(m, struct etherip_header *);
if (eip->eip_ver != ETHERIP_VERSION) {
/* discard unknown versions */
m_freem(m);
goto drop;
}
m_adj_decap(m, sizeof(struct etherip_header));
m->m_flags &= ~(M_BCAST|M_MCAST);
m->m_pkthdr.rcvif = ifp;
if (ifp->if_bridge) {
oldifp = ifp;
eh = mtod(m, struct ether_header *);
if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
if (ETHER_IS_BROADCAST(eh->ether_dhost))
m->m_flags |= M_BCAST;
else
m->m_flags |= M_MCAST;
if_inc_counter(ifp, IFCOUNTER_IMCASTS, 1);
}
BRIDGE_INPUT(ifp, m);
if (m != NULL && ifp != oldifp) {
/*
* The bridge gave us back itself or one of the
* members for which the frame is addressed.
*/
ether_demux(ifp, m);
return;
}
}
if (m != NULL)
m_freem(m);
return;
default:
if (ng_gif_input_orphan_p != NULL)
(*ng_gif_input_orphan_p)(ifp, m, af);
else
m_freem(m);
return;
}
if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
M_SETFIB(m, ifp->if_fib);
netisr_dispatch(isr, m);
return;
drop:
if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
}
static int
gif_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
struct ifreq *ifr = (struct ifreq*)data;
struct gif_softc *sc;
u_int options;
int error;
switch (cmd) {
case SIOCSIFADDR:
ifp->if_flags |= IFF_UP;
case SIOCADDMULTI:
case SIOCDELMULTI:
case SIOCGIFMTU:
case SIOCSIFFLAGS:
return (0);
case SIOCSIFMTU:
if (ifr->ifr_mtu < GIF_MTU_MIN ||
ifr->ifr_mtu > GIF_MTU_MAX)
return (EINVAL);
else
ifp->if_mtu = ifr->ifr_mtu;
return (0);
}
sx_xlock(&gif_ioctl_sx);
sc = ifp->if_softc;
if (sc == NULL) {
error = ENXIO;
goto bad;
}
error = 0;
switch (cmd) {
case SIOCDIFPHYADDR:
if (sc->gif_family == 0)
break;
gif_delete_tunnel(sc);
break;
#ifdef INET
case SIOCSIFPHYADDR:
case SIOCGIFPSRCADDR:
case SIOCGIFPDSTADDR:
error = in_gif_ioctl(sc, cmd, data);
break;
#endif
#ifdef INET6
case SIOCSIFPHYADDR_IN6:
case SIOCGIFPSRCADDR_IN6:
case SIOCGIFPDSTADDR_IN6:
error = in6_gif_ioctl(sc, cmd, data);
break;
#endif
case SIOCGTUNFIB:
ifr->ifr_fib = sc->gif_fibnum;
break;
case SIOCSTUNFIB:
if ((error = priv_check(curthread, PRIV_NET_GIF)) != 0)
break;
if (ifr->ifr_fib >= rt_numfibs)
error = EINVAL;
else
sc->gif_fibnum = ifr->ifr_fib;
break;
case GIFGOPTS:
options = sc->gif_options;
error = copyout(&options, ifr_data_get_ptr(ifr),
sizeof(options));
break;
case GIFSOPTS:
if ((error = priv_check(curthread, PRIV_NET_GIF)) != 0)
break;
error = copyin(ifr_data_get_ptr(ifr), &options,
sizeof(options));
if (error)
break;
if (options & ~GIF_OPTMASK) {
error = EINVAL;
break;
}
if (sc->gif_options != options) {
switch (sc->gif_family) {
#ifdef INET
case AF_INET:
error = in_gif_setopts(sc, options);
break;
#endif
#ifdef INET6
case AF_INET6:
error = in6_gif_setopts(sc, options);
break;
#endif
default:
/* No need to invoke AF-handler */
sc->gif_options = options;
}
}
break;
default:
error = EINVAL;
break;
}
if (error == 0 && sc->gif_family != 0) {
if (
#ifdef INET
cmd == SIOCSIFPHYADDR ||
#endif
#ifdef INET6
cmd == SIOCSIFPHYADDR_IN6 ||
#endif
0) {
if_link_state_change(ifp, LINK_STATE_UP);
}
}
bad:
sx_xunlock(&gif_ioctl_sx);
return (error);
}
static void
gif_delete_tunnel(struct gif_softc *sc)
{
sx_assert(&gif_ioctl_sx, SA_XLOCKED);
if (sc->gif_family != 0) {
CK_LIST_REMOVE(sc, srchash);
CK_LIST_REMOVE(sc, chain);
/* Wait until it become safe to free gif_hdr */
GIF_WAIT();
free(sc->gif_hdr, M_GIF);
}
sc->gif_family = 0;
GIF2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
if_link_state_change(GIF2IFP(sc), LINK_STATE_DOWN);
}
