2 * SPDX-License-Identifier: BSD-2-Clause-NetBSD
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>
38 __FBSDID("$FreeBSD$");
41 #include "opt_inet6.h"
43 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/socket.h>
47 #include <sys/socketvar.h>
48 #include <sys/sockio.h>
50 #include <sys/errno.h>
51 #include <sys/kernel.h>
52 #include <sys/sysctl.h>
53 #include <sys/malloc.h>
57 #include <net/if_var.h>
58 #include <net/if_private.h>
61 #include <netinet/in.h>
62 #include <netinet/in_var.h>
63 #include <netinet/in_pcb.h>
64 #include <netinet/ip.h>
65 #include <netinet/ip_encap.h>
66 #include <netinet/ip_var.h>
67 #include <netinet/udp.h>
68 #include <netinet/udp_var.h>
71 #include <netinet/ip6.h>
74 #include <net/if_gre.h>
75 #include <machine/in_cksum.h>
78 VNET_DEFINE(int, ip_gre_ttl) = GRE_TTL;
79 #define V_ip_gre_ttl VNET(ip_gre_ttl)
80 SYSCTL_INT(_net_inet_ip, OID_AUTO, grettl, CTLFLAG_VNET | CTLFLAG_RW,
81 &VNET_NAME(ip_gre_ttl), 0, "Default TTL value for encapsulated packets");
83 struct in_gre_socket {
84 struct gre_socket base;
87 VNET_DEFINE_STATIC(struct gre_sockets *, ipv4_sockets) = NULL;
88 VNET_DEFINE_STATIC(struct gre_list *, ipv4_hashtbl) = NULL;
89 VNET_DEFINE_STATIC(struct gre_list *, ipv4_srchashtbl) = NULL;
90 #define V_ipv4_sockets VNET(ipv4_sockets)
91 #define V_ipv4_hashtbl VNET(ipv4_hashtbl)
92 #define V_ipv4_srchashtbl VNET(ipv4_srchashtbl)
93 #define GRE_HASH(src, dst) (V_ipv4_hashtbl[\
94 in_gre_hashval((src), (dst)) & (GRE_HASH_SIZE - 1)])
95 #define GRE_SRCHASH(src) (V_ipv4_srchashtbl[\
96 fnv_32_buf(&(src), sizeof(src), FNV1_32_INIT) & (GRE_HASH_SIZE - 1)])
97 #define GRE_SOCKHASH(src) (V_ipv4_sockets[\
98 fnv_32_buf(&(src), sizeof(src), FNV1_32_INIT) & (GRE_HASH_SIZE - 1)])
99 #define GRE_HASH_SC(sc) GRE_HASH((sc)->gre_oip.ip_src.s_addr,\
100 (sc)->gre_oip.ip_dst.s_addr)
103 in_gre_hashval(in_addr_t src, in_addr_t dst)
107 ret = fnv_32_buf(&src, sizeof(src), FNV1_32_INIT);
108 return (fnv_32_buf(&dst, sizeof(dst), ret));
111 static struct gre_socket*
112 in_gre_lookup_socket(in_addr_t addr)
114 struct gre_socket *gs;
115 struct in_gre_socket *s;
117 CK_LIST_FOREACH(gs, &GRE_SOCKHASH(addr), chain) {
118 s = __containerof(gs, struct in_gre_socket, base);
126 in_gre_checkdup(const struct gre_softc *sc, in_addr_t src, in_addr_t dst,
129 struct gre_list *head;
130 struct gre_softc *tmp;
131 struct gre_socket *gs;
133 if (sc->gre_family == AF_INET &&
134 sc->gre_oip.ip_src.s_addr == src &&
135 sc->gre_oip.ip_dst.s_addr == dst &&
136 (sc->gre_options & GRE_UDPENCAP) == (opts & GRE_UDPENCAP))
139 if (opts & GRE_UDPENCAP) {
140 gs = in_gre_lookup_socket(src);
145 head = &GRE_HASH(src, dst);
147 CK_LIST_FOREACH(tmp, head, chain) {
150 if (tmp->gre_oip.ip_src.s_addr == src &&
151 tmp->gre_oip.ip_dst.s_addr == dst)
152 return (EADDRNOTAVAIL);
158 in_gre_lookup(const struct mbuf *m, int off, int proto, void **arg)
161 struct gre_softc *sc;
163 if (V_ipv4_hashtbl == NULL)
167 ip = mtod(m, const struct ip *);
168 CK_LIST_FOREACH(sc, &GRE_HASH(ip->ip_dst.s_addr,
169 ip->ip_src.s_addr), chain) {
171 * This is an inbound packet, its ip_dst is source address
174 if (sc->gre_oip.ip_src.s_addr == ip->ip_dst.s_addr &&
175 sc->gre_oip.ip_dst.s_addr == ip->ip_src.s_addr) {
176 if ((GRE2IFP(sc)->if_flags & IFF_UP) == 0)
179 return (ENCAP_DRV_LOOKUP);
186 * Check that ingress address belongs to local host.
189 in_gre_set_running(struct gre_softc *sc)
192 if (in_localip(sc->gre_oip.ip_src))
193 GRE2IFP(sc)->if_drv_flags |= IFF_DRV_RUNNING;
195 GRE2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
199 * ifaddr_event handler.
200 * Clear IFF_DRV_RUNNING flag when ingress address disappears to prevent
201 * source address spoofing.
204 in_gre_srcaddr(void *arg __unused, const struct sockaddr *sa,
207 const struct sockaddr_in *sin;
208 struct gre_softc *sc;
210 /* Check that VNET is ready */
211 if (V_ipv4_hashtbl == NULL)
215 sin = (const struct sockaddr_in *)sa;
216 CK_LIST_FOREACH(sc, &GRE_SRCHASH(sin->sin_addr.s_addr), srchash) {
217 if (sc->gre_oip.ip_src.s_addr != sin->sin_addr.s_addr)
219 in_gre_set_running(sc);
224 in_gre_udp_input(struct mbuf *m, int off, struct inpcb *inp,
225 const struct sockaddr *sa, void *ctx)
227 struct gre_socket *gs;
228 struct gre_softc *sc;
233 gs = (struct gre_socket *)ctx;
234 dst = ((const struct sockaddr_in *)sa)->sin_addr.s_addr;
235 CK_LIST_FOREACH(sc, &gs->list, chain) {
236 if (sc->gre_oip.ip_dst.s_addr == dst)
239 if (sc != NULL && (GRE2IFP(sc)->if_flags & IFF_UP) != 0){
240 gre_input(m, off + sizeof(struct udphdr), IPPROTO_UDP, sc);
249 in_gre_setup_socket(struct gre_softc *sc)
252 struct sockaddr_in sin;
253 struct in_gre_socket *s;
254 struct gre_socket *gs;
259 * NOTE: we are protected with gre_ioctl_sx lock.
261 * First check that socket is already configured.
262 * If so, check that source address was not changed.
263 * If address is different, check that there are no other tunnels
266 addr = sc->gre_oip.ip_src.s_addr;
269 s = __containerof(gs, struct in_gre_socket, base);
270 if (s->addr != addr) {
271 if (CK_LIST_EMPTY(&gs->list)) {
272 CK_LIST_REMOVE(gs, chain);
274 NET_EPOCH_CALL(gre_sofree, &gs->epoch_ctx);
276 gs = sc->gre_so = NULL;
282 * Check that socket for given address is already
285 gs = in_gre_lookup_socket(addr);
287 s = malloc(sizeof(*s), M_GRE, M_WAITOK | M_ZERO);
291 error = socreate(sc->gre_family, &gs->so,
292 SOCK_DGRAM, IPPROTO_UDP, curthread->td_ucred,
295 if_printf(GRE2IFP(sc),
296 "cannot create socket: %d\n", error);
301 error = udp_set_kernel_tunneling(gs->so,
302 in_gre_udp_input, NULL, gs);
304 if_printf(GRE2IFP(sc),
305 "cannot set UDP tunneling: %d\n", error);
309 memset(&sopt, 0, sizeof(sopt));
310 sopt.sopt_dir = SOPT_SET;
311 sopt.sopt_level = IPPROTO_IP;
312 sopt.sopt_name = IP_BINDANY;
313 sopt.sopt_val = &value;
314 sopt.sopt_valsize = sizeof(value);
316 error = sosetopt(gs->so, &sopt);
318 if_printf(GRE2IFP(sc),
319 "cannot set IP_BINDANY opt: %d\n", error);
323 memset(&sin, 0, sizeof(sin));
324 sin.sin_family = AF_INET;
325 sin.sin_len = sizeof(sin);
326 sin.sin_addr.s_addr = addr;
327 sin.sin_port = htons(GRE_UDPPORT);
328 error = sobind(gs->so, (struct sockaddr *)&sin,
331 if_printf(GRE2IFP(sc),
332 "cannot bind socket: %d\n", error);
335 /* Add socket to the chain */
336 CK_LIST_INSERT_HEAD(&GRE_SOCKHASH(addr), gs, chain);
340 /* Add softc to the socket's list */
341 CK_LIST_INSERT_HEAD(&gs->list, sc, chain);
351 in_gre_attach(struct gre_softc *sc)
353 struct epoch_tracker et;
357 if (sc->gre_options & GRE_UDPENCAP) {
358 sc->gre_csumflags = CSUM_UDP;
359 sc->gre_hlen = sizeof(struct greudp);
360 sc->gre_oip.ip_p = IPPROTO_UDP;
361 gh = &sc->gre_udphdr->gi_gre;
362 gre_update_udphdr(sc, &sc->gre_udp,
363 in_pseudo(sc->gre_oip.ip_src.s_addr,
364 sc->gre_oip.ip_dst.s_addr, 0));
366 sc->gre_hlen = sizeof(struct greip);
367 sc->gre_oip.ip_p = IPPROTO_GRE;
368 gh = &sc->gre_iphdr->gi_gre;
370 sc->gre_oip.ip_v = IPVERSION;
371 sc->gre_oip.ip_hl = sizeof(struct ip) >> 2;
372 gre_update_hdr(sc, gh);
375 * If we return error, this means that sc is not linked,
376 * and caller should reset gre_family and free(sc->gre_hdr).
378 if (sc->gre_options & GRE_UDPENCAP) {
379 error = in_gre_setup_socket(sc);
383 CK_LIST_INSERT_HEAD(&GRE_HASH_SC(sc), sc, chain);
384 CK_LIST_INSERT_HEAD(&GRE_SRCHASH(sc->gre_oip.ip_src.s_addr),
387 /* Set IFF_DRV_RUNNING if interface is ready */
389 in_gre_set_running(sc);
395 in_gre_setopts(struct gre_softc *sc, u_long cmd, uint32_t value)
399 /* NOTE: we are protected with gre_ioctl_sx lock */
400 MPASS(cmd == GRESKEY || cmd == GRESOPTS || cmd == GRESPORT);
401 MPASS(sc->gre_family == AF_INET);
404 * If we are going to change encapsulation protocol, do check
405 * for duplicate tunnels. Return EEXIST here to do not confuse
408 if (cmd == GRESOPTS &&
409 (sc->gre_options & GRE_UDPENCAP) != (value & GRE_UDPENCAP) &&
410 in_gre_checkdup(sc, sc->gre_oip.ip_src.s_addr,
411 sc->gre_oip.ip_dst.s_addr, value) == EADDRNOTAVAIL)
414 CK_LIST_REMOVE(sc, chain);
415 CK_LIST_REMOVE(sc, srchash);
422 sc->gre_options = value;
425 sc->gre_port = value;
428 error = in_gre_attach(sc);
431 free(sc->gre_hdr, M_GRE);
437 in_gre_ioctl(struct gre_softc *sc, u_long cmd, caddr_t data)
439 struct ifreq *ifr = (struct ifreq *)data;
440 struct sockaddr_in *dst, *src;
444 /* NOTE: we are protected with gre_ioctl_sx lock */
448 src = &((struct in_aliasreq *)data)->ifra_addr;
449 dst = &((struct in_aliasreq *)data)->ifra_dstaddr;
452 if (src->sin_family != dst->sin_family ||
453 src->sin_family != AF_INET ||
454 src->sin_len != dst->sin_len ||
455 src->sin_len != sizeof(*src))
457 if (src->sin_addr.s_addr == INADDR_ANY ||
458 dst->sin_addr.s_addr == INADDR_ANY) {
459 error = EADDRNOTAVAIL;
462 if (V_ipv4_hashtbl == NULL) {
463 V_ipv4_hashtbl = gre_hashinit();
464 V_ipv4_srchashtbl = gre_hashinit();
465 V_ipv4_sockets = (struct gre_sockets *)gre_hashinit();
467 error = in_gre_checkdup(sc, src->sin_addr.s_addr,
468 dst->sin_addr.s_addr, sc->gre_options);
469 if (error == EADDRNOTAVAIL)
471 if (error == EEXIST) {
472 /* Addresses are the same. Just return. */
476 ip = malloc(sizeof(struct greudp) + 3 * sizeof(uint32_t),
477 M_GRE, M_WAITOK | M_ZERO);
478 ip->ip_src.s_addr = src->sin_addr.s_addr;
479 ip->ip_dst.s_addr = dst->sin_addr.s_addr;
480 if (sc->gre_family != 0) {
481 /* Detach existing tunnel first */
482 CK_LIST_REMOVE(sc, chain);
483 CK_LIST_REMOVE(sc, srchash);
485 free(sc->gre_hdr, M_GRE);
486 /* XXX: should we notify about link state change? */
488 sc->gre_family = AF_INET;
491 sc->gre_iseq = UINT32_MAX;
492 error = in_gre_attach(sc);
495 free(sc->gre_hdr, M_GRE);
498 case SIOCGIFPSRCADDR:
499 case SIOCGIFPDSTADDR:
500 if (sc->gre_family != AF_INET) {
501 error = EADDRNOTAVAIL;
504 src = (struct sockaddr_in *)&ifr->ifr_addr;
505 memset(src, 0, sizeof(*src));
506 src->sin_family = AF_INET;
507 src->sin_len = sizeof(*src);
508 src->sin_addr = (cmd == SIOCGIFPSRCADDR) ?
509 sc->gre_oip.ip_src: sc->gre_oip.ip_dst;
510 error = prison_if(curthread->td_ucred, (struct sockaddr *)src);
512 memset(src, 0, sizeof(*src));
519 in_gre_output(struct mbuf *m, int af, int hlen)
523 gi = mtod(m, struct greip *);
527 * gre_transmit() has used M_PREPEND() that doesn't guarantee
528 * m_data is contiguous more than hlen bytes. Use m_copydata()
529 * here to avoid m_pullup().
531 m_copydata(m, hlen + offsetof(struct ip, ip_tos),
532 sizeof(u_char), &gi->gi_ip.ip_tos);
533 m_copydata(m, hlen + offsetof(struct ip, ip_id),
534 sizeof(u_short), (caddr_t)&gi->gi_ip.ip_id);
538 gi->gi_ip.ip_tos = 0; /* XXX */
539 ip_fillid(&gi->gi_ip);
543 gi->gi_ip.ip_ttl = V_ip_gre_ttl;
544 gi->gi_ip.ip_len = htons(m->m_pkthdr.len);
545 return (ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL));
548 static const struct srcaddrtab *ipv4_srcaddrtab = NULL;
549 static const struct encaptab *ecookie = NULL;
550 static const struct encap_config ipv4_encap_cfg = {
551 .proto = IPPROTO_GRE,
552 .min_length = sizeof(struct greip) + sizeof(struct ip),
553 .exact_match = ENCAP_DRV_LOOKUP,
554 .lookup = in_gre_lookup,
562 if (!IS_DEFAULT_VNET(curvnet))
564 ipv4_srcaddrtab = ip_encap_register_srcaddr(in_gre_srcaddr,
566 ecookie = ip_encap_attach(&ipv4_encap_cfg, NULL, M_WAITOK);
573 if (IS_DEFAULT_VNET(curvnet)) {
574 ip_encap_detach(ecookie);
575 ip_encap_unregister_srcaddr(ipv4_srcaddrtab);
577 if (V_ipv4_hashtbl != NULL) {
578 gre_hashdestroy(V_ipv4_hashtbl);
579 V_ipv4_hashtbl = NULL;
581 gre_hashdestroy(V_ipv4_srchashtbl);
582 gre_hashdestroy((struct gre_list *)V_ipv4_sockets);