/*-
* Copyright (c) 2014, 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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>
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/jail.h>
#include <sys/systm.h>
#include <sys/socket.h>
#include <sys/socketvar.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 <sys/proc.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_private.h>
#include <net/vnet.h>
#include <netinet/in.h>
#ifdef INET
#include <net/ethernet.h>
#include <netinet/ip.h>
#endif
#include <netinet/in_pcb.h>
#include <netinet/ip_encap.h>
#include <netinet/ip_var.h>
#include <netinet/ip6.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet6/ip6_var.h>
#include <netinet6/in6_var.h>
#include <netinet6/scope6_var.h>
#include <net/if_gre.h>
VNET_DEFINE(int, ip6_gre_hlim) = IPV6_DEFHLIM;
#define V_ip6_gre_hlim VNET(ip6_gre_hlim)
SYSCTL_DECL(_net_inet6_ip6);
SYSCTL_INT(_net_inet6_ip6, OID_AUTO, grehlim, CTLFLAG_VNET | CTLFLAG_RW,
&VNET_NAME(ip6_gre_hlim), 0, "Default hop limit for encapsulated packets");
struct in6_gre_socket {
struct gre_socket base;
struct in6_addr addr; /* scope zone id is embedded */
};
VNET_DEFINE_STATIC(struct gre_sockets *, ipv6_sockets) = NULL;
VNET_DEFINE_STATIC(struct gre_list *, ipv6_hashtbl) = NULL;
VNET_DEFINE_STATIC(struct gre_list *, ipv6_srchashtbl) = NULL;
#define V_ipv6_sockets VNET(ipv6_sockets)
#define V_ipv6_hashtbl VNET(ipv6_hashtbl)
#define V_ipv6_srchashtbl VNET(ipv6_srchashtbl)
#define GRE_HASH(src, dst) (V_ipv6_hashtbl[\
in6_gre_hashval((src), (dst)) & (GRE_HASH_SIZE - 1)])
#define GRE_SRCHASH(src) (V_ipv6_srchashtbl[\
fnv_32_buf((src), sizeof(*src), FNV1_32_INIT) & (GRE_HASH_SIZE - 1)])
#define GRE_SOCKHASH(src) (V_ipv6_sockets[\
fnv_32_buf((src), sizeof(*src), FNV1_32_INIT) & (GRE_HASH_SIZE - 1)])
#define GRE_HASH_SC(sc) GRE_HASH(&(sc)->gre_oip6.ip6_src,\
&(sc)->gre_oip6.ip6_dst)
static uint32_t
in6_gre_hashval(const struct in6_addr *src, const struct in6_addr *dst)
{
uint32_t ret;
ret = fnv_32_buf(src, sizeof(*src), FNV1_32_INIT);
return (fnv_32_buf(dst, sizeof(*dst), ret));
}
static struct gre_socket*
in6_gre_lookup_socket(const struct in6_addr *addr)
{
struct gre_socket *gs;
struct in6_gre_socket *s;
CK_LIST_FOREACH(gs, &GRE_SOCKHASH(addr), chain) {
s = __containerof(gs, struct in6_gre_socket, base);
if (IN6_ARE_ADDR_EQUAL(&s->addr, addr))
break;
}
return (gs);
}
static int
in6_gre_checkdup(const struct gre_softc *sc, const struct in6_addr *src,
const struct in6_addr *dst, uint32_t opts)
{
struct gre_list *head;
struct gre_softc *tmp;
struct gre_socket *gs;
if (sc->gre_family == AF_INET6 &&
IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_src, src) &&
IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_dst, dst) &&
(sc->gre_options & GRE_UDPENCAP) == (opts & GRE_UDPENCAP))
return (EEXIST);
if (opts & GRE_UDPENCAP) {
gs = in6_gre_lookup_socket(src);
if (gs == NULL)
return (0);
head = &gs->list;
} else
head = &GRE_HASH(src, dst);
CK_LIST_FOREACH(tmp, head, chain) {
if (tmp == sc)
continue;
if (IN6_ARE_ADDR_EQUAL(&tmp->gre_oip6.ip6_src, src) &&
IN6_ARE_ADDR_EQUAL(&tmp->gre_oip6.ip6_dst, dst))
return (EADDRNOTAVAIL);
}
return (0);
}
static int
in6_gre_lookup(const struct mbuf *m, int off, int proto, void **arg)
{
const struct ip6_hdr *ip6;
struct gre_softc *sc;
if (V_ipv6_hashtbl == NULL)
return (0);
NET_EPOCH_ASSERT();
ip6 = mtod(m, const struct ip6_hdr *);
CK_LIST_FOREACH(sc, &GRE_HASH(&ip6->ip6_dst, &ip6->ip6_src), chain) {
/*
* This is an inbound packet, its ip6_dst is source address
* in softc.
*/
if (IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_src,
&ip6->ip6_dst) &&
IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_dst,
&ip6->ip6_src)) {
if ((GRE2IFP(sc)->if_flags & IFF_UP) == 0)
return (0);
*arg = sc;
return (ENCAP_DRV_LOOKUP);
}
}
return (0);
}
/*
* Check that ingress address belongs to local host.
*/
static void
in6_gre_set_running(struct gre_softc *sc)
{
if (in6_localip(&sc->gre_oip6.ip6_src))
GRE2IFP(sc)->if_drv_flags |= IFF_DRV_RUNNING;
else
GRE2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
}
/*
* ifaddr_event handler.
* Clear IFF_DRV_RUNNING flag when ingress address disappears to prevent
* source address spoofing.
*/
static void
in6_gre_srcaddr(void *arg __unused, const struct sockaddr *sa,
int event __unused)
{
const struct sockaddr_in6 *sin;
struct gre_softc *sc;
/* Check that VNET is ready */
if (V_ipv6_hashtbl == NULL)
return;
NET_EPOCH_ASSERT();
sin = (const struct sockaddr_in6 *)sa;
CK_LIST_FOREACH(sc, &GRE_SRCHASH(&sin->sin6_addr), srchash) {
if (IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_src,
&sin->sin6_addr) == 0)
continue;
in6_gre_set_running(sc);
}
}
static bool
in6_gre_udp_input(struct mbuf *m, int off, struct inpcb *inp,
const struct sockaddr *sa, void *ctx)
{
struct gre_socket *gs;
struct gre_softc *sc;
struct sockaddr_in6 dst;
NET_EPOCH_ASSERT();
gs = (struct gre_socket *)ctx;
dst = *(const struct sockaddr_in6 *)sa;
if (sa6_embedscope(&dst, 0)) {
m_freem(m);
return (true);
}
CK_LIST_FOREACH(sc, &gs->list, chain) {
if (IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_dst, &dst.sin6_addr))
break;
}
if (sc != NULL && (GRE2IFP(sc)->if_flags & IFF_UP) != 0){
gre_input(m, off + sizeof(struct udphdr), IPPROTO_UDP, sc);
return (true);
}
m_freem(m);
return (true);
}
static int
in6_gre_setup_socket(struct gre_softc *sc)
{
struct sockopt sopt;
struct sockaddr_in6 sin6;
struct in6_gre_socket *s;
struct gre_socket *gs;
int error, value;
/*
* NOTE: we are protected with gre_ioctl_sx lock.
*
* First check that socket is already configured.
* If so, check that source address was not changed.
* If address is different, check that there are no other tunnels
* and close socket.
*/
gs = sc->gre_so;
if (gs != NULL) {
s = __containerof(gs, struct in6_gre_socket, base);
if (!IN6_ARE_ADDR_EQUAL(&s->addr, &sc->gre_oip6.ip6_src)) {
if (CK_LIST_EMPTY(&gs->list)) {
CK_LIST_REMOVE(gs, chain);
soclose(gs->so);
NET_EPOCH_CALL(gre_sofree, &gs->epoch_ctx);
}
gs = sc->gre_so = NULL;
}
}
if (gs == NULL) {
/*
* Check that socket for given address is already
* configured.
*/
gs = in6_gre_lookup_socket(&sc->gre_oip6.ip6_src);
if (gs == NULL) {
s = malloc(sizeof(*s), M_GRE, M_WAITOK | M_ZERO);
s->addr = sc->gre_oip6.ip6_src;
gs = &s->base;
error = socreate(sc->gre_family, &gs->so,
SOCK_DGRAM, IPPROTO_UDP, curthread->td_ucred,
curthread);
if (error != 0) {
if_printf(GRE2IFP(sc),
"cannot create socket: %d\n", error);
free(s, M_GRE);
return (error);
}
error = udp_set_kernel_tunneling(gs->so,
in6_gre_udp_input, NULL, gs);
if (error != 0) {
if_printf(GRE2IFP(sc),
"cannot set UDP tunneling: %d\n", error);
goto fail;
}
memset(&sopt, 0, sizeof(sopt));
sopt.sopt_dir = SOPT_SET;
sopt.sopt_level = IPPROTO_IPV6;
sopt.sopt_name = IPV6_BINDANY;
sopt.sopt_val = &value;
sopt.sopt_valsize = sizeof(value);
value = 1;
error = sosetopt(gs->so, &sopt);
if (error != 0) {
if_printf(GRE2IFP(sc),
"cannot set IPV6_BINDANY opt: %d\n",
error);
goto fail;
}
memset(&sin6, 0, sizeof(sin6));
sin6.sin6_family = AF_INET6;
sin6.sin6_len = sizeof(sin6);
sin6.sin6_addr = sc->gre_oip6.ip6_src;
sin6.sin6_port = htons(GRE_UDPPORT);
error = sa6_recoverscope(&sin6);
if (error != 0) {
if_printf(GRE2IFP(sc),
"cannot determine scope zone id: %d\n",
error);
goto fail;
}
error = sobind(gs->so, (struct sockaddr *)&sin6,
curthread);
if (error != 0) {
if_printf(GRE2IFP(sc),
"cannot bind socket: %d\n", error);
goto fail;
}
/* Add socket to the chain */
CK_LIST_INSERT_HEAD(
&GRE_SOCKHASH(&sc->gre_oip6.ip6_src), gs, chain);
}
}
/* Add softc to the socket's list */
CK_LIST_INSERT_HEAD(&gs->list, sc, chain);
sc->gre_so = gs;
return (0);
fail:
soclose(gs->so);
free(s, M_GRE);
return (error);
}
static int
in6_gre_attach(struct gre_softc *sc)
{
struct grehdr *gh;
int error;
if (sc->gre_options & GRE_UDPENCAP) {
sc->gre_csumflags = CSUM_UDP_IPV6;
sc->gre_hlen = sizeof(struct greudp6);
sc->gre_oip6.ip6_nxt = IPPROTO_UDP;
gh = &sc->gre_udp6hdr->gi6_gre;
gre_update_udphdr(sc, &sc->gre_udp6,
in6_cksum_pseudo(&sc->gre_oip6, 0, 0, 0));
} else {
sc->gre_hlen = sizeof(struct greip6);
sc->gre_oip6.ip6_nxt = IPPROTO_GRE;
gh = &sc->gre_ip6hdr->gi6_gre;
}
sc->gre_oip6.ip6_vfc = IPV6_VERSION;
gre_update_hdr(sc, gh);
/*
* If we return error, this means that sc is not linked,
* and caller should reset gre_family and free(sc->gre_hdr).
*/
if (sc->gre_options & GRE_UDPENCAP) {
error = in6_gre_setup_socket(sc);
if (error != 0)
return (error);
} else
CK_LIST_INSERT_HEAD(&GRE_HASH_SC(sc), sc, chain);
CK_LIST_INSERT_HEAD(&GRE_SRCHASH(&sc->gre_oip6.ip6_src), sc, srchash);
/* Set IFF_DRV_RUNNING if interface is ready */
in6_gre_set_running(sc);
return (0);
}
int
in6_gre_setopts(struct gre_softc *sc, u_long cmd, uint32_t value)
{
int error;
/* NOTE: we are protected with gre_ioctl_sx lock */
MPASS(cmd == GRESKEY || cmd == GRESOPTS || cmd == GRESPORT);
MPASS(sc->gre_family == AF_INET6);
/*
* If we are going to change encapsulation protocol, do check
* for duplicate tunnels. Return EEXIST here to do not confuse
* user.
*/
if (cmd == GRESOPTS &&
(sc->gre_options & GRE_UDPENCAP) != (value & GRE_UDPENCAP) &&
in6_gre_checkdup(sc, &sc->gre_oip6.ip6_src,
&sc->gre_oip6.ip6_dst, value) == EADDRNOTAVAIL)
return (EEXIST);
CK_LIST_REMOVE(sc, chain);
CK_LIST_REMOVE(sc, srchash);
GRE_WAIT();
switch (cmd) {
case GRESKEY:
sc->gre_key = value;
break;
case GRESOPTS:
sc->gre_options = value;
break;
case GRESPORT:
sc->gre_port = value;
break;
}
error = in6_gre_attach(sc);
if (error != 0) {
sc->gre_family = 0;
free(sc->gre_hdr, M_GRE);
}
return (error);
}
int
in6_gre_ioctl(struct gre_softc *sc, u_long cmd, caddr_t data)
{
struct in6_ifreq *ifr = (struct in6_ifreq *)data;
struct sockaddr_in6 *dst, *src;
struct ip6_hdr *ip6;
int error;
/* NOTE: we are protected with gre_ioctl_sx lock */
error = EINVAL;
switch (cmd) {
case SIOCSIFPHYADDR_IN6:
src = &((struct in6_aliasreq *)data)->ifra_addr;
dst = &((struct in6_aliasreq *)data)->ifra_dstaddr;
/* sanity checks */
if (src->sin6_family != dst->sin6_family ||
src->sin6_family != AF_INET6 ||
src->sin6_len != dst->sin6_len ||
src->sin6_len != sizeof(*src))
break;
if (IN6_IS_ADDR_UNSPECIFIED(&src->sin6_addr) ||
IN6_IS_ADDR_UNSPECIFIED(&dst->sin6_addr)) {
error = EADDRNOTAVAIL;
break;
}
/*
* Check validity of the scope zone ID of the
* addresses, and convert it into the kernel
* internal form if necessary.
*/
if ((error = sa6_embedscope(src, 0)) != 0 ||
(error = sa6_embedscope(dst, 0)) != 0)
break;
if (V_ipv6_hashtbl == NULL) {
V_ipv6_hashtbl = gre_hashinit();
V_ipv6_srchashtbl = gre_hashinit();
V_ipv6_sockets = (struct gre_sockets *)gre_hashinit();
}
error = in6_gre_checkdup(sc, &src->sin6_addr,
&dst->sin6_addr, sc->gre_options);
if (error == EADDRNOTAVAIL)
break;
if (error == EEXIST) {
/* Addresses are the same. Just return. */
error = 0;
break;
}
ip6 = malloc(sizeof(struct greudp6) + 3 * sizeof(uint32_t),
M_GRE, M_WAITOK | M_ZERO);
ip6->ip6_src = src->sin6_addr;
ip6->ip6_dst = dst->sin6_addr;
if (sc->gre_family != 0) {
/* Detach existing tunnel first */
CK_LIST_REMOVE(sc, chain);
CK_LIST_REMOVE(sc, srchash);
GRE_WAIT();
free(sc->gre_hdr, M_GRE);
/* XXX: should we notify about link state change? */
}
sc->gre_family = AF_INET6;
sc->gre_hdr = ip6;
sc->gre_oseq = 0;
sc->gre_iseq = UINT32_MAX;
error = in6_gre_attach(sc);
if (error != 0) {
sc->gre_family = 0;
free(sc->gre_hdr, M_GRE);
}
break;
case SIOCGIFPSRCADDR_IN6:
case SIOCGIFPDSTADDR_IN6:
if (sc->gre_family != AF_INET6) {
error = EADDRNOTAVAIL;
break;
}
src = (struct sockaddr_in6 *)&ifr->ifr_addr;
memset(src, 0, sizeof(*src));
src->sin6_family = AF_INET6;
src->sin6_len = sizeof(*src);
src->sin6_addr = (cmd == SIOCGIFPSRCADDR_IN6) ?
sc->gre_oip6.ip6_src: sc->gre_oip6.ip6_dst;
error = prison_if(curthread->td_ucred, (struct sockaddr *)src);
if (error == 0)
error = sa6_recoverscope(src);
if (error != 0)
memset(src, 0, sizeof(*src));
break;
}
return (error);
}
int
in6_gre_output(struct mbuf *m, int af __unused, int hlen __unused,
uint32_t flowid)
{
struct greip6 *gi6;
gi6 = mtod(m, struct greip6 *);
gi6->gi6_ip6.ip6_hlim = V_ip6_gre_hlim;
gi6->gi6_ip6.ip6_flow |= flowid & IPV6_FLOWLABEL_MASK;
return (ip6_output(m, NULL, NULL, IPV6_MINMTU, NULL, NULL, NULL));
}
static const struct srcaddrtab *ipv6_srcaddrtab = NULL;
static const struct encaptab *ecookie = NULL;
static const struct encap_config ipv6_encap_cfg = {
.proto = IPPROTO_GRE,
.min_length = sizeof(struct greip6) +
#ifdef INET
sizeof(struct ip),
#else
sizeof(struct ip6_hdr),
#endif
.exact_match = ENCAP_DRV_LOOKUP,
.lookup = in6_gre_lookup,
.input = gre_input
};
void
in6_gre_init(void)
{
if (!IS_DEFAULT_VNET(curvnet))
return;
ipv6_srcaddrtab = ip6_encap_register_srcaddr(in6_gre_srcaddr,
NULL, M_WAITOK);
ecookie = ip6_encap_attach(&ipv6_encap_cfg, NULL, M_WAITOK);
}
void
in6_gre_uninit(void)
{
if (IS_DEFAULT_VNET(curvnet)) {
ip6_encap_detach(ecookie);
ip6_encap_unregister_srcaddr(ipv6_srcaddrtab);
}
if (V_ipv6_hashtbl != NULL) {
gre_hashdestroy(V_ipv6_hashtbl);
V_ipv6_hashtbl = NULL;
GRE_WAIT();
gre_hashdestroy(V_ipv6_srchashtbl);
gre_hashdestroy((struct gre_list *)V_ipv6_sockets);
}
}
plain