2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * Copyright (c) 2018 Andrey V. Elsukov <ae@FreeBSD.org>
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 itojun Exp $
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
39 #include "opt_inet6.h"
41 #include <sys/param.h>
42 #include <sys/systm.h>
44 #include <sys/socket.h>
45 #include <sys/sockio.h>
47 #include <sys/errno.h>
48 #include <sys/kernel.h>
49 #include <sys/sysctl.h>
50 #include <sys/malloc.h>
53 #include <net/ethernet.h>
55 #include <net/if_var.h>
56 #include <net/if_private.h>
57 #include <net/route.h>
60 #include <netinet/in.h>
61 #include <netinet/in_systm.h>
62 #include <netinet/ip.h>
63 #include <netinet/ip_var.h>
64 #include <netinet/in_var.h>
65 #include <netinet/ip_encap.h>
66 #include <netinet/ip_ecn.h>
67 #include <netinet/in_fib.h>
70 #include <netinet/ip6.h>
73 #include <net/if_gif.h>
76 VNET_DEFINE_STATIC(int, ip_gif_ttl) = GIF_TTL;
77 #define V_ip_gif_ttl VNET(ip_gif_ttl)
78 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_VNET | CTLFLAG_RW,
79 &VNET_NAME(ip_gif_ttl), 0, "Default TTL value for encapsulated packets");
82 * We keep interfaces in a hash table using src+dst as key.
83 * Interfaces with GIF_IGNORE_SOURCE flag are linked into plain list.
85 VNET_DEFINE_STATIC(struct gif_list *, ipv4_hashtbl) = NULL;
86 VNET_DEFINE_STATIC(struct gif_list *, ipv4_srchashtbl) = NULL;
87 VNET_DEFINE_STATIC(struct gif_list, ipv4_list) = CK_LIST_HEAD_INITIALIZER();
88 #define V_ipv4_hashtbl VNET(ipv4_hashtbl)
89 #define V_ipv4_srchashtbl VNET(ipv4_srchashtbl)
90 #define V_ipv4_list VNET(ipv4_list)
92 #define GIF_HASH(src, dst) (V_ipv4_hashtbl[\
93 in_gif_hashval((src), (dst)) & (GIF_HASH_SIZE - 1)])
94 #define GIF_SRCHASH(src) (V_ipv4_srchashtbl[\
95 fnv_32_buf(&(src), sizeof(src), FNV1_32_INIT) & (GIF_HASH_SIZE - 1)])
96 #define GIF_HASH_SC(sc) GIF_HASH((sc)->gif_iphdr->ip_src.s_addr,\
97 (sc)->gif_iphdr->ip_dst.s_addr)
99 in_gif_hashval(in_addr_t src, in_addr_t dst)
103 ret = fnv_32_buf(&src, sizeof(src), FNV1_32_INIT);
104 return (fnv_32_buf(&dst, sizeof(dst), ret));
108 in_gif_checkdup(const struct gif_softc *sc, in_addr_t src, in_addr_t dst)
110 struct gif_softc *tmp;
112 if (sc->gif_family == AF_INET &&
113 sc->gif_iphdr->ip_src.s_addr == src &&
114 sc->gif_iphdr->ip_dst.s_addr == dst)
117 CK_LIST_FOREACH(tmp, &GIF_HASH(src, dst), chain) {
120 if (tmp->gif_iphdr->ip_src.s_addr == src &&
121 tmp->gif_iphdr->ip_dst.s_addr == dst)
122 return (EADDRNOTAVAIL);
128 * Check that ingress address belongs to local host.
131 in_gif_set_running(struct gif_softc *sc)
134 if (in_localip(sc->gif_iphdr->ip_src))
135 GIF2IFP(sc)->if_drv_flags |= IFF_DRV_RUNNING;
137 GIF2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
141 * ifaddr_event handler.
142 * Clear IFF_DRV_RUNNING flag when ingress address disappears to prevent
143 * source address spoofing.
146 in_gif_srcaddr(void *arg __unused, const struct sockaddr *sa,
149 const struct sockaddr_in *sin;
150 struct gif_softc *sc;
152 /* Check that VNET is ready */
153 if (V_ipv4_hashtbl == NULL)
157 sin = (const struct sockaddr_in *)sa;
158 CK_LIST_FOREACH(sc, &GIF_SRCHASH(sin->sin_addr.s_addr), srchash) {
159 if (sc->gif_iphdr->ip_src.s_addr != sin->sin_addr.s_addr)
161 in_gif_set_running(sc);
166 in_gif_attach(struct gif_softc *sc)
169 if (sc->gif_options & GIF_IGNORE_SOURCE)
170 CK_LIST_INSERT_HEAD(&V_ipv4_list, sc, chain);
172 CK_LIST_INSERT_HEAD(&GIF_HASH_SC(sc), sc, chain);
174 CK_LIST_INSERT_HEAD(&GIF_SRCHASH(sc->gif_iphdr->ip_src.s_addr),
179 in_gif_setopts(struct gif_softc *sc, u_int options)
182 /* NOTE: we are protected with gif_ioctl_sx lock */
183 MPASS(sc->gif_family == AF_INET);
184 MPASS(sc->gif_options != options);
186 if ((options & GIF_IGNORE_SOURCE) !=
187 (sc->gif_options & GIF_IGNORE_SOURCE)) {
188 CK_LIST_REMOVE(sc, srchash);
189 CK_LIST_REMOVE(sc, chain);
190 sc->gif_options = options;
197 in_gif_ioctl(struct gif_softc *sc, u_long cmd, caddr_t data)
199 struct ifreq *ifr = (struct ifreq *)data;
200 struct epoch_tracker et;
201 struct sockaddr_in *dst, *src;
205 /* NOTE: we are protected with gif_ioctl_sx lock */
209 src = &((struct in_aliasreq *)data)->ifra_addr;
210 dst = &((struct in_aliasreq *)data)->ifra_dstaddr;
213 if (src->sin_family != dst->sin_family ||
214 src->sin_family != AF_INET ||
215 src->sin_len != dst->sin_len ||
216 src->sin_len != sizeof(*src))
218 if (src->sin_addr.s_addr == INADDR_ANY ||
219 dst->sin_addr.s_addr == INADDR_ANY) {
220 error = EADDRNOTAVAIL;
223 if (V_ipv4_hashtbl == NULL) {
224 V_ipv4_hashtbl = gif_hashinit();
225 V_ipv4_srchashtbl = gif_hashinit();
227 error = in_gif_checkdup(sc, src->sin_addr.s_addr,
228 dst->sin_addr.s_addr);
229 if (error == EADDRNOTAVAIL)
231 if (error == EEXIST) {
232 /* Addresses are the same. Just return. */
236 ip = malloc(sizeof(*ip), M_GIF, M_WAITOK | M_ZERO);
237 ip->ip_src.s_addr = src->sin_addr.s_addr;
238 ip->ip_dst.s_addr = dst->sin_addr.s_addr;
239 if (sc->gif_family != 0) {
240 /* Detach existing tunnel first */
241 CK_LIST_REMOVE(sc, srchash);
242 CK_LIST_REMOVE(sc, chain);
244 free(sc->gif_hdr, M_GIF);
245 /* XXX: should we notify about link state change? */
247 sc->gif_family = AF_INET;
251 in_gif_set_running(sc);
254 case SIOCGIFPSRCADDR:
255 case SIOCGIFPDSTADDR:
256 if (sc->gif_family != AF_INET) {
257 error = EADDRNOTAVAIL;
260 src = (struct sockaddr_in *)&ifr->ifr_addr;
261 memset(src, 0, sizeof(*src));
262 src->sin_family = AF_INET;
263 src->sin_len = sizeof(*src);
264 src->sin_addr = (cmd == SIOCGIFPSRCADDR) ?
265 sc->gif_iphdr->ip_src: sc->gif_iphdr->ip_dst;
266 error = prison_if(curthread->td_ucred, (struct sockaddr *)src);
268 memset(src, 0, sizeof(*src));
275 in_gif_output(struct ifnet *ifp, struct mbuf *m, int proto, uint8_t ecn)
277 struct gif_softc *sc = ifp->if_softc;
281 /* prepend new IP header */
283 len = sizeof(struct ip);
284 #ifndef __NO_STRICT_ALIGNMENT
285 if (proto == IPPROTO_ETHERIP)
286 len += ETHERIP_ALIGN;
288 M_PREPEND(m, len, M_NOWAIT);
291 #ifndef __NO_STRICT_ALIGNMENT
292 if (proto == IPPROTO_ETHERIP) {
293 len = mtod(m, vm_offset_t) & 3;
294 KASSERT(len == 0 || len == ETHERIP_ALIGN,
295 ("in_gif_output: unexpected misalignment"));
297 m->m_len -= ETHERIP_ALIGN;
300 ip = mtod(m, struct ip *);
302 MPASS(sc->gif_family == AF_INET);
303 bcopy(sc->gif_iphdr, ip, sizeof(struct ip));
305 /* version will be set in ip_output() */
306 ip->ip_ttl = V_ip_gif_ttl;
307 ip->ip_len = htons(m->m_pkthdr.len);
310 return (ip_output(m, NULL, NULL, 0, NULL, NULL));
314 in_gif_input(struct mbuf *m, int off, int proto, void *arg)
316 struct gif_softc *sc = arg;
324 KMOD_IPSTAT_INC(ips_nogif);
325 return (IPPROTO_DONE);
328 if ((gifp->if_flags & IFF_UP) != 0) {
329 ip = mtod(m, struct ip *);
332 gif_input(m, gifp, proto, ecn);
335 KMOD_IPSTAT_INC(ips_nogif);
337 return (IPPROTO_DONE);
341 in_gif_lookup(const struct mbuf *m, int off, int proto, void **arg)
344 struct gif_softc *sc;
347 if (V_ipv4_hashtbl == NULL)
351 ip = mtod(m, const struct ip *);
353 * NOTE: it is safe to iterate without any locking here, because softc
354 * can be reclaimed only when we are not within net_epoch_preempt
355 * section, but ip_encap lookup+input are executed in epoch section.
358 CK_LIST_FOREACH(sc, &GIF_HASH(ip->ip_dst.s_addr,
359 ip->ip_src.s_addr), chain) {
361 * This is an inbound packet, its ip_dst is source address
364 if (sc->gif_iphdr->ip_src.s_addr == ip->ip_dst.s_addr &&
365 sc->gif_iphdr->ip_dst.s_addr == ip->ip_src.s_addr) {
366 ret = ENCAP_DRV_LOOKUP;
372 * Check the list of interfaces with GIF_IGNORE_SOURCE flag.
374 CK_LIST_FOREACH(sc, &V_ipv4_list, chain) {
375 if (sc->gif_iphdr->ip_src.s_addr == ip->ip_dst.s_addr) {
376 ret = 32 + 8; /* src + proto */
382 if ((GIF2IFP(sc)->if_flags & IFF_UP) == 0)
384 /* ingress filters on outer source */
385 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0) {
386 if (fib4_check_urpf(sc->gif_fibnum, ip->ip_src, 0, NHR_NONE,
387 m->m_pkthdr.rcvif) == 0)
394 static const struct srcaddrtab *ipv4_srcaddrtab;
396 const struct encap_config encap;
397 const struct encaptab *cookie;
398 } ipv4_encap_cfg[] = {
401 .proto = IPPROTO_IPV4,
402 .min_length = 2 * sizeof(struct ip),
403 .exact_match = ENCAP_DRV_LOOKUP,
404 .lookup = in_gif_lookup,
405 .input = in_gif_input
411 .proto = IPPROTO_IPV6,
412 .min_length = sizeof(struct ip) +
413 sizeof(struct ip6_hdr),
414 .exact_match = ENCAP_DRV_LOOKUP,
415 .lookup = in_gif_lookup,
416 .input = in_gif_input
422 .proto = IPPROTO_ETHERIP,
423 .min_length = sizeof(struct ip) +
424 sizeof(struct etherip_header) +
425 sizeof(struct ether_header),
426 .exact_match = ENCAP_DRV_LOOKUP,
427 .lookup = in_gif_lookup,
428 .input = in_gif_input
438 if (!IS_DEFAULT_VNET(curvnet))
441 ipv4_srcaddrtab = ip_encap_register_srcaddr(in_gif_srcaddr,
443 for (i = 0; i < nitems(ipv4_encap_cfg); i++)
444 ipv4_encap_cfg[i].cookie = ip_encap_attach(
445 &ipv4_encap_cfg[i].encap, NULL, M_WAITOK);
453 if (IS_DEFAULT_VNET(curvnet)) {
454 for (i = 0; i < nitems(ipv4_encap_cfg); i++)
455 ip_encap_detach(ipv4_encap_cfg[i].cookie);
456 ip_encap_unregister_srcaddr(ipv4_srcaddrtab);
458 if (V_ipv4_hashtbl != NULL) {
459 gif_hashdestroy(V_ipv4_hashtbl);
460 V_ipv4_hashtbl = NULL;
462 gif_hashdestroy(V_ipv4_srchashtbl);