2 * SPDX-License-Identifier: BSD-2-Clause
4 * Copyright (c) 1998 The NetBSD Foundation, Inc.
5 * Copyright (c) 2014, 2018 Andrey V. Elsukov <ae@FreeBSD.org>
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Heiko W.Rupp <hwr@pilhuhn.de>
11 * IPv6-over-GRE contributed by Gert Doering <gert@greenie.muc.de>
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
22 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
24 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
25 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
26 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32 * POSSIBILITY OF SUCH DAMAGE.
34 * $NetBSD: ip_gre.c,v 1.29 2003/09/05 23:02:43 itojun Exp $
37 #include <sys/cdefs.h>
39 #include "opt_inet6.h"
41 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/socket.h>
45 #include <sys/socketvar.h>
46 #include <sys/sockio.h>
48 #include <sys/errno.h>
49 #include <sys/kernel.h>
50 #include <sys/sysctl.h>
51 #include <sys/malloc.h>
55 #include <net/if_var.h>
56 #include <net/if_private.h>
59 #include <netinet/in.h>
60 #include <netinet/in_var.h>
61 #include <netinet/in_pcb.h>
62 #include <netinet/ip.h>
63 #include <netinet/ip_encap.h>
64 #include <netinet/ip_var.h>
65 #include <netinet/udp.h>
66 #include <netinet/udp_var.h>
69 #include <netinet/ip6.h>
72 #include <net/if_gre.h>
73 #include <machine/in_cksum.h>
76 VNET_DEFINE(int, ip_gre_ttl
) = GRE_TTL
;
77 #define V_ip_gre_ttl VNET(ip_gre_ttl)
78 SYSCTL_INT(_net_inet_ip
, OID_AUTO
, grettl
, CTLFLAG_VNET
| CTLFLAG_RW
,
79 &VNET_NAME(ip_gre_ttl
), 0, "Default TTL value for encapsulated packets");
81 struct in_gre_socket
{
82 struct gre_socket base
;
85 VNET_DEFINE_STATIC(struct gre_sockets
*, ipv4_sockets
) = NULL
;
86 VNET_DEFINE_STATIC(struct gre_list
*, ipv4_hashtbl
) = NULL
;
87 VNET_DEFINE_STATIC(struct gre_list
*, ipv4_srchashtbl
) = NULL
;
88 #define V_ipv4_sockets VNET(ipv4_sockets)
89 #define V_ipv4_hashtbl VNET(ipv4_hashtbl)
90 #define V_ipv4_srchashtbl VNET(ipv4_srchashtbl)
91 #define GRE_HASH(src, dst) (V_ipv4_hashtbl[\
92 in_gre_hashval((src), (dst)) & (GRE_HASH_SIZE - 1)])
93 #define GRE_SRCHASH(src) (V_ipv4_srchashtbl[\
94 fnv_32_buf(&(src), sizeof(src), FNV1_32_INIT) & (GRE_HASH_SIZE - 1)])
95 #define GRE_SOCKHASH(src) (V_ipv4_sockets[\
96 fnv_32_buf(&(src), sizeof(src), FNV1_32_INIT) & (GRE_HASH_SIZE - 1)])
97 #define GRE_HASH_SC(sc) GRE_HASH((sc)->gre_oip.ip_src.s_addr,\
98 (sc)->gre_oip.ip_dst.s_addr)
101 in_gre_hashval(in_addr_t src
, in_addr_t dst
)
105 ret
= fnv_32_buf(&src
, sizeof(src
), FNV1_32_INIT
);
106 return (fnv_32_buf(&dst
, sizeof(dst
), ret
));
109 static struct gre_socket
*
110 in_gre_lookup_socket(in_addr_t addr
)
112 struct gre_socket
*gs
;
113 struct in_gre_socket
*s
;
115 CK_LIST_FOREACH(gs
, &GRE_SOCKHASH(addr
), chain
) {
116 s
= __containerof(gs
, struct in_gre_socket
, base
);
124 in_gre_checkdup(const struct gre_softc
*sc
, in_addr_t src
, in_addr_t dst
,
127 struct gre_list
*head
;
128 struct gre_softc
*tmp
;
129 struct gre_socket
*gs
;
131 if (sc
->gre_family
== AF_INET
&&
132 sc
->gre_oip
.ip_src
.s_addr
== src
&&
133 sc
->gre_oip
.ip_dst
.s_addr
== dst
&&
134 (sc
->gre_options
& GRE_UDPENCAP
) == (opts
& GRE_UDPENCAP
))
137 if (opts
& GRE_UDPENCAP
) {
138 gs
= in_gre_lookup_socket(src
);
143 head
= &GRE_HASH(src
, dst
);
145 CK_LIST_FOREACH(tmp
, head
, chain
) {
148 if (tmp
->gre_oip
.ip_src
.s_addr
== src
&&
149 tmp
->gre_oip
.ip_dst
.s_addr
== dst
)
150 return (EADDRNOTAVAIL
);
156 in_gre_lookup(const struct mbuf
*m
, int off
, int proto
, void **arg
)
159 struct gre_softc
*sc
;
161 if (V_ipv4_hashtbl
== NULL
)
165 ip
= mtod(m
, const struct ip
*);
166 CK_LIST_FOREACH(sc
, &GRE_HASH(ip
->ip_dst
.s_addr
,
167 ip
->ip_src
.s_addr
), chain
) {
169 * This is an inbound packet, its ip_dst is source address
172 if (sc
->gre_oip
.ip_src
.s_addr
== ip
->ip_dst
.s_addr
&&
173 sc
->gre_oip
.ip_dst
.s_addr
== ip
->ip_src
.s_addr
) {
174 if ((GRE2IFP(sc
)->if_flags
& IFF_UP
) == 0)
177 return (ENCAP_DRV_LOOKUP
);
184 * Check that ingress address belongs to local host.
187 in_gre_set_running(struct gre_softc
*sc
)
190 if (in_localip(sc
->gre_oip
.ip_src
))
191 GRE2IFP(sc
)->if_drv_flags
|= IFF_DRV_RUNNING
;
193 GRE2IFP(sc
)->if_drv_flags
&= ~IFF_DRV_RUNNING
;
197 * ifaddr_event handler.
198 * Clear IFF_DRV_RUNNING flag when ingress address disappears to prevent
199 * source address spoofing.
202 in_gre_srcaddr(void *arg __unused
, const struct sockaddr
*sa
,
205 const struct sockaddr_in
*sin
;
206 struct gre_softc
*sc
;
208 /* Check that VNET is ready */
209 if (V_ipv4_hashtbl
== NULL
)
213 sin
= (const struct sockaddr_in
*)sa
;
214 CK_LIST_FOREACH(sc
, &GRE_SRCHASH(sin
->sin_addr
.s_addr
), srchash
) {
215 if (sc
->gre_oip
.ip_src
.s_addr
!= sin
->sin_addr
.s_addr
)
217 in_gre_set_running(sc
);
222 in_gre_udp_input(struct mbuf
*m
, int off
, struct inpcb
*inp
,
223 const struct sockaddr
*sa
, void *ctx
)
225 struct gre_socket
*gs
;
226 struct gre_softc
*sc
;
231 gs
= (struct gre_socket
*)ctx
;
232 dst
= ((const struct sockaddr_in
*)sa
)->sin_addr
.s_addr
;
233 CK_LIST_FOREACH(sc
, &gs
->list
, chain
) {
234 if (sc
->gre_oip
.ip_dst
.s_addr
== dst
)
237 if (sc
!= NULL
&& (GRE2IFP(sc
)->if_flags
& IFF_UP
) != 0){
238 gre_input(m
, off
+ sizeof(struct udphdr
), IPPROTO_UDP
, sc
);
247 in_gre_setup_socket(struct gre_softc
*sc
)
250 struct sockaddr_in sin
;
251 struct in_gre_socket
*s
;
252 struct gre_socket
*gs
;
257 * NOTE: we are protected with gre_ioctl_sx lock.
259 * First check that socket is already configured.
260 * If so, check that source address was not changed.
261 * If address is different, check that there are no other tunnels
264 addr
= sc
->gre_oip
.ip_src
.s_addr
;
267 s
= __containerof(gs
, struct in_gre_socket
, base
);
268 if (s
->addr
!= addr
) {
269 if (CK_LIST_EMPTY(&gs
->list
)) {
270 CK_LIST_REMOVE(gs
, chain
);
272 NET_EPOCH_CALL(gre_sofree
, &gs
->epoch_ctx
);
274 gs
= sc
->gre_so
= NULL
;
280 * Check that socket for given address is already
283 gs
= in_gre_lookup_socket(addr
);
285 s
= malloc(sizeof(*s
), M_GRE
, M_WAITOK
| M_ZERO
);
289 error
= socreate(sc
->gre_family
, &gs
->so
,
290 SOCK_DGRAM
, IPPROTO_UDP
, curthread
->td_ucred
,
293 if_printf(GRE2IFP(sc
),
294 "cannot create socket: %d\n", error
);
299 error
= udp_set_kernel_tunneling(gs
->so
,
300 in_gre_udp_input
, NULL
, gs
);
302 if_printf(GRE2IFP(sc
),
303 "cannot set UDP tunneling: %d\n", error
);
307 memset(&sopt
, 0, sizeof(sopt
));
308 sopt
.sopt_dir
= SOPT_SET
;
309 sopt
.sopt_level
= IPPROTO_IP
;
310 sopt
.sopt_name
= IP_BINDANY
;
311 sopt
.sopt_val
= &value
;
312 sopt
.sopt_valsize
= sizeof(value
);
314 error
= sosetopt(gs
->so
, &sopt
);
316 if_printf(GRE2IFP(sc
),
317 "cannot set IP_BINDANY opt: %d\n", error
);
321 memset(&sin
, 0, sizeof(sin
));
322 sin
.sin_family
= AF_INET
;
323 sin
.sin_len
= sizeof(sin
);
324 sin
.sin_addr
.s_addr
= addr
;
325 sin
.sin_port
= htons(GRE_UDPPORT
);
326 error
= sobind(gs
->so
, (struct sockaddr
*)&sin
,
329 if_printf(GRE2IFP(sc
),
330 "cannot bind socket: %d\n", error
);
333 /* Add socket to the chain */
334 CK_LIST_INSERT_HEAD(&GRE_SOCKHASH(addr
), gs
, chain
);
338 /* Add softc to the socket's list */
339 CK_LIST_INSERT_HEAD(&gs
->list
, sc
, chain
);
349 in_gre_attach(struct gre_softc
*sc
)
351 struct epoch_tracker et
;
355 if (sc
->gre_options
& GRE_UDPENCAP
) {
356 sc
->gre_csumflags
= CSUM_UDP
;
357 sc
->gre_hlen
= sizeof(struct greudp
);
358 sc
->gre_oip
.ip_p
= IPPROTO_UDP
;
359 gh
= &sc
->gre_udphdr
->gi_gre
;
360 gre_update_udphdr(sc
, &sc
->gre_udp
,
361 in_pseudo(sc
->gre_oip
.ip_src
.s_addr
,
362 sc
->gre_oip
.ip_dst
.s_addr
, 0));
364 sc
->gre_hlen
= sizeof(struct greip
);
365 sc
->gre_oip
.ip_p
= IPPROTO_GRE
;
366 gh
= &sc
->gre_iphdr
->gi_gre
;
368 sc
->gre_oip
.ip_v
= IPVERSION
;
369 sc
->gre_oip
.ip_hl
= sizeof(struct ip
) >> 2;
370 gre_update_hdr(sc
, gh
);
373 * If we return error, this means that sc is not linked,
374 * and caller should reset gre_family and free(sc->gre_hdr).
376 if (sc
->gre_options
& GRE_UDPENCAP
) {
377 error
= in_gre_setup_socket(sc
);
381 CK_LIST_INSERT_HEAD(&GRE_HASH_SC(sc
), sc
, chain
);
382 CK_LIST_INSERT_HEAD(&GRE_SRCHASH(sc
->gre_oip
.ip_src
.s_addr
),
385 /* Set IFF_DRV_RUNNING if interface is ready */
387 in_gre_set_running(sc
);
393 in_gre_setopts(struct gre_softc
*sc
, u_long cmd
, uint32_t value
)
397 /* NOTE: we are protected with gre_ioctl_sx lock */
398 MPASS(cmd
== GRESKEY
|| cmd
== GRESOPTS
|| cmd
== GRESPORT
);
399 MPASS(sc
->gre_family
== AF_INET
);
402 * If we are going to change encapsulation protocol, do check
403 * for duplicate tunnels. Return EEXIST here to do not confuse
406 if (cmd
== GRESOPTS
&&
407 (sc
->gre_options
& GRE_UDPENCAP
) != (value
& GRE_UDPENCAP
) &&
408 in_gre_checkdup(sc
, sc
->gre_oip
.ip_src
.s_addr
,
409 sc
->gre_oip
.ip_dst
.s_addr
, value
) == EADDRNOTAVAIL
)
412 CK_LIST_REMOVE(sc
, chain
);
413 CK_LIST_REMOVE(sc
, srchash
);
420 sc
->gre_options
= value
;
423 sc
->gre_port
= value
;
426 error
= in_gre_attach(sc
);
429 free(sc
->gre_hdr
, M_GRE
);
435 in_gre_ioctl(struct gre_softc
*sc
, u_long cmd
, caddr_t data
)
437 struct ifreq
*ifr
= (struct ifreq
*)data
;
438 struct sockaddr_in
*dst
, *src
;
442 /* NOTE: we are protected with gre_ioctl_sx lock */
446 src
= &((struct in_aliasreq
*)data
)->ifra_addr
;
447 dst
= &((struct in_aliasreq
*)data
)->ifra_dstaddr
;
450 if (src
->sin_family
!= dst
->sin_family
||
451 src
->sin_family
!= AF_INET
||
452 src
->sin_len
!= dst
->sin_len
||
453 src
->sin_len
!= sizeof(*src
))
455 if (src
->sin_addr
.s_addr
== INADDR_ANY
||
456 dst
->sin_addr
.s_addr
== INADDR_ANY
) {
457 error
= EADDRNOTAVAIL
;
460 if (V_ipv4_hashtbl
== NULL
) {
461 V_ipv4_hashtbl
= gre_hashinit();
462 V_ipv4_srchashtbl
= gre_hashinit();
463 V_ipv4_sockets
= (struct gre_sockets
*)gre_hashinit();
465 error
= in_gre_checkdup(sc
, src
->sin_addr
.s_addr
,
466 dst
->sin_addr
.s_addr
, sc
->gre_options
);
467 if (error
== EADDRNOTAVAIL
)
469 if (error
== EEXIST
) {
470 /* Addresses are the same. Just return. */
474 ip
= malloc(sizeof(struct greudp
) + 3 * sizeof(uint32_t),
475 M_GRE
, M_WAITOK
| M_ZERO
);
476 ip
->ip_src
.s_addr
= src
->sin_addr
.s_addr
;
477 ip
->ip_dst
.s_addr
= dst
->sin_addr
.s_addr
;
478 if (sc
->gre_family
!= 0) {
479 /* Detach existing tunnel first */
480 CK_LIST_REMOVE(sc
, chain
);
481 CK_LIST_REMOVE(sc
, srchash
);
483 free(sc
->gre_hdr
, M_GRE
);
484 /* XXX: should we notify about link state change? */
486 sc
->gre_family
= AF_INET
;
489 sc
->gre_iseq
= UINT32_MAX
;
490 error
= in_gre_attach(sc
);
493 free(sc
->gre_hdr
, M_GRE
);
496 case SIOCGIFPSRCADDR
:
497 case SIOCGIFPDSTADDR
:
498 if (sc
->gre_family
!= AF_INET
) {
499 error
= EADDRNOTAVAIL
;
502 src
= (struct sockaddr_in
*)&ifr
->ifr_addr
;
503 memset(src
, 0, sizeof(*src
));
504 src
->sin_family
= AF_INET
;
505 src
->sin_len
= sizeof(*src
);
506 src
->sin_addr
= (cmd
== SIOCGIFPSRCADDR
) ?
507 sc
->gre_oip
.ip_src
: sc
->gre_oip
.ip_dst
;
508 error
= prison_if(curthread
->td_ucred
, (struct sockaddr
*)src
);
510 memset(src
, 0, sizeof(*src
));
517 in_gre_output(struct mbuf
*m
, int af
, int hlen
)
521 gi
= mtod(m
, struct greip
*);
525 * gre_transmit() has used M_PREPEND() that doesn't guarantee
526 * m_data is contiguous more than hlen bytes. Use m_copydata()
527 * here to avoid m_pullup().
529 m_copydata(m
, hlen
+ offsetof(struct ip
, ip_tos
),
530 sizeof(u_char
), &gi
->gi_ip
.ip_tos
);
531 m_copydata(m
, hlen
+ offsetof(struct ip
, ip_id
),
532 sizeof(u_short
), (caddr_t
)&gi
->gi_ip
.ip_id
);
536 gi
->gi_ip
.ip_tos
= 0; /* XXX */
537 ip_fillid(&gi
->gi_ip
);
541 gi
->gi_ip
.ip_ttl
= V_ip_gre_ttl
;
542 gi
->gi_ip
.ip_len
= htons(m
->m_pkthdr
.len
);
543 return (ip_output(m
, NULL
, NULL
, IP_FORWARDING
, NULL
, NULL
));
546 static const struct srcaddrtab
*ipv4_srcaddrtab
= NULL
;
547 static const struct encaptab
*ecookie
= NULL
;
548 static const struct encap_config ipv4_encap_cfg
= {
549 .proto
= IPPROTO_GRE
,
550 .min_length
= sizeof(struct greip
) + sizeof(struct ip
),
551 .exact_match
= ENCAP_DRV_LOOKUP
,
552 .lookup
= in_gre_lookup
,
560 if (!IS_DEFAULT_VNET(curvnet
))
562 ipv4_srcaddrtab
= ip_encap_register_srcaddr(in_gre_srcaddr
,
564 ecookie
= ip_encap_attach(&ipv4_encap_cfg
, NULL
, M_WAITOK
);
571 if (IS_DEFAULT_VNET(curvnet
)) {
572 ip_encap_detach(ecookie
);
573 ip_encap_unregister_srcaddr(ipv4_srcaddrtab
);
575 if (V_ipv4_hashtbl
!= NULL
) {
576 gre_hashdestroy(V_ipv4_hashtbl
);
577 V_ipv4_hashtbl
= NULL
;
579 gre_hashdestroy(V_ipv4_srchashtbl
);
580 gre_hashdestroy((struct gre_list
*)V_ipv4_sockets
);