1 /* $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 itojun Exp $ */
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the project nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
35 #include "opt_mrouting.h"
37 #include "opt_inet6.h"
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/socket.h>
42 #include <sys/sockio.h>
44 #include <sys/errno.h>
45 #include <sys/kernel.h>
46 #include <sys/sysctl.h>
47 #include <sys/protosw.h>
48 #include <sys/malloc.h>
51 #include <net/if_var.h>
52 #include <net/route.h>
55 #include <netinet/in.h>
56 #include <netinet/in_systm.h>
57 #include <netinet/ip.h>
58 #include <netinet/ip_var.h>
59 #include <netinet/in_gif.h>
60 #include <netinet/in_var.h>
61 #include <netinet/ip_encap.h>
62 #include <netinet/ip_ecn.h>
65 #include <netinet/ip6.h>
69 #include <netinet/ip_mroute.h>
72 #include <net/if_gif.h>
74 static int gif_validate4(const struct ip *, struct gif_softc *,
77 extern struct domain inetdomain;
78 struct protosw in_gif_protosw = {
80 .pr_domain = &inetdomain,
81 .pr_protocol = 0/* IPPROTO_IPV[46] */,
82 .pr_flags = PR_ATOMIC|PR_ADDR,
83 .pr_input = in_gif_input,
84 .pr_output = (pr_output_t*)rip_output,
85 .pr_ctloutput = rip_ctloutput,
86 .pr_usrreqs = &rip_usrreqs
89 VNET_DEFINE(int, ip_gif_ttl) = GIF_TTL;
90 #define V_ip_gif_ttl VNET(ip_gif_ttl)
91 SYSCTL_VNET_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW,
92 &VNET_NAME(ip_gif_ttl), 0, "");
95 in_gif_output(struct ifnet *ifp, int family, struct mbuf *m)
97 struct gif_softc *sc = ifp->if_softc;
98 struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst;
99 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc;
100 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst;
101 struct ip iphdr; /* capsule IP header, host byte ordered */
102 struct etherip_header eiphdr;
103 int error, len, proto;
108 if (sin_src == NULL || sin_dst == NULL ||
109 sin_src->sin_family != AF_INET ||
110 sin_dst->sin_family != AF_INET) {
121 proto = IPPROTO_IPV4;
122 if (m->m_len < sizeof(*ip)) {
123 m = m_pullup(m, sizeof(*ip));
127 ip = mtod(m, struct ip *);
136 proto = IPPROTO_IPV6;
137 if (m->m_len < sizeof(*ip6)) {
138 m = m_pullup(m, sizeof(*ip6));
142 ip6 = mtod(m, struct ip6_hdr *);
143 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
148 proto = IPPROTO_ETHERIP;
151 * GIF_SEND_REVETHIP (disabled by default) intentionally
152 * sends an EtherIP packet with revered version field in
153 * the header. This is a knob for backward compatibility
154 * with FreeBSD 7.2R or prior.
156 if ((sc->gif_options & GIF_SEND_REVETHIP)) {
158 eiphdr.eip_resvl = ETHERIP_VERSION;
159 eiphdr.eip_resvh = 0;
161 eiphdr.eip_ver = ETHERIP_VERSION;
162 eiphdr.eip_resvl = 0;
163 eiphdr.eip_resvh = 0;
165 /* prepend Ethernet-in-IP header */
166 M_PREPEND(m, sizeof(struct etherip_header), M_NOWAIT);
167 if (m && m->m_len < sizeof(struct etherip_header))
168 m = m_pullup(m, sizeof(struct etherip_header));
171 bcopy(&eiphdr, mtod(m, struct etherip_header *),
172 sizeof(struct etherip_header));
177 printf("in_gif_output: warning: unknown family %d passed\n",
184 bzero(&iphdr, sizeof(iphdr));
185 iphdr.ip_src = sin_src->sin_addr;
186 /* bidirectional configured tunnel mode */
187 if (sin_dst->sin_addr.s_addr != INADDR_ANY)
188 iphdr.ip_dst = sin_dst->sin_addr;
194 /* version will be set in ip_output() */
195 iphdr.ip_ttl = V_ip_gif_ttl;
196 iphdr.ip_len = htons(m->m_pkthdr.len + sizeof(struct ip));
197 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE,
198 &iphdr.ip_tos, &tos);
200 /* prepend new IP header */
201 len = sizeof(struct ip);
202 #ifndef __NO_STRICT_ALIGNMENT
203 if (family == AF_LINK)
204 len += ETHERIP_ALIGN;
206 M_PREPEND(m, len, M_NOWAIT);
207 if (m != NULL && m->m_len < len)
208 m = m_pullup(m, len);
210 printf("ENOBUFS in in_gif_output %d\n", __LINE__);
213 #ifndef __NO_STRICT_ALIGNMENT
214 if (family == AF_LINK) {
215 len = mtod(m, vm_offset_t) & 3;
216 KASSERT(len == 0 || len == ETHERIP_ALIGN,
217 ("in_gif_output: unexpected misalignment"));
219 m->m_len -= ETHERIP_ALIGN;
222 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip));
224 M_SETFIB(m, sc->gif_fibnum);
226 if (dst->sin_family != sin_dst->sin_family ||
227 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) {
228 /* cache route doesn't match */
229 bzero(dst, sizeof(*dst));
230 dst->sin_family = sin_dst->sin_family;
231 dst->sin_len = sizeof(struct sockaddr_in);
232 dst->sin_addr = sin_dst->sin_addr;
233 if (sc->gif_ro.ro_rt) {
234 RTFREE(sc->gif_ro.ro_rt);
235 sc->gif_ro.ro_rt = NULL;
238 GIF2IFP(sc)->if_mtu = GIF_MTU;
242 if (sc->gif_ro.ro_rt == NULL) {
243 in_rtalloc_ign(&sc->gif_ro, 0, sc->gif_fibnum);
244 if (sc->gif_ro.ro_rt == NULL) {
249 /* if it constitutes infinite encapsulation, punt. */
250 if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
252 return ENETUNREACH; /* XXX */
255 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu
260 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL);
262 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) &&
263 sc->gif_ro.ro_rt != NULL) {
264 RTFREE(sc->gif_ro.ro_rt);
265 sc->gif_ro.ro_rt = NULL;
272 in_gif_input(struct mbuf *m, int off)
274 struct ifnet *gifp = NULL;
275 struct gif_softc *sc;
281 ip = mtod(m, struct ip *);
284 sc = (struct gif_softc *)encap_getarg(m);
287 KMOD_IPSTAT_INC(ips_nogif);
292 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
294 KMOD_IPSTAT_INC(ips_nogif);
307 if (m->m_len < sizeof(*ip)) {
308 m = m_pullup(m, sizeof(*ip));
312 ip = mtod(m, struct ip *);
313 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
314 ECN_ALLOWED : ECN_NOCARE,
315 &otos, &ip->ip_tos) == 0) {
326 u_int8_t itos, oitos;
329 if (m->m_len < sizeof(*ip6)) {
330 m = m_pullup(m, sizeof(*ip6));
334 ip6 = mtod(m, struct ip6_hdr *);
335 itos = oitos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
336 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
337 ECN_ALLOWED : ECN_NOCARE,
338 &otos, &itos) == 0) {
343 ip6->ip6_flow &= ~htonl(0xff << 20);
344 ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
349 case IPPROTO_ETHERIP:
354 KMOD_IPSTAT_INC(ips_nogif);
358 gif_input(m, af, gifp);
363 * validate outer address.
366 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp)
368 struct sockaddr_in *src, *dst;
369 struct in_ifaddr *ia4;
371 src = (struct sockaddr_in *)sc->gif_psrc;
372 dst = (struct sockaddr_in *)sc->gif_pdst;
374 /* check for address match */
375 if (src->sin_addr.s_addr != ip->ip_dst.s_addr ||
376 dst->sin_addr.s_addr != ip->ip_src.s_addr)
379 /* martian filters on outer source - NOT done in ip_input! */
380 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr)))
382 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) {
383 case 0: case 127: case 255:
387 /* reject packets with broadcast on source */
388 /* XXXRW: should use hash lists? */
390 TAILQ_FOREACH(ia4, &V_in_ifaddrhead, ia_link) {
391 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0)
393 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) {
400 /* ingress filters on outer source */
401 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) {
402 struct sockaddr_in sin;
405 bzero(&sin, sizeof(sin));
406 sin.sin_family = AF_INET;
407 sin.sin_len = sizeof(struct sockaddr_in);
408 sin.sin_addr = ip->ip_src;
409 /* XXX MRT check for the interface we would use on output */
410 rt = in_rtalloc1((struct sockaddr *)&sin, 0,
411 0UL, sc->gif_fibnum);
412 if (!rt || rt->rt_ifp != ifp) {
414 log(LOG_WARNING, "%s: packet from 0x%x dropped "
415 "due to ingress filter\n", if_name(GIF2IFP(sc)),
416 (u_int32_t)ntohl(sin.sin_addr.s_addr));
429 * we know that we are in IFF_UP, outer address available, and outer family
430 * matched the physical addr family. see gif_encapcheck().
433 gif_encapcheck4(const struct mbuf *m, int off, int proto, void *arg)
436 struct gif_softc *sc;
439 /* sanity check done in caller */
440 sc = (struct gif_softc *)arg;
442 /* LINTED const cast */
443 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip);
444 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
446 return gif_validate4(&ip, sc, ifp);
450 in_gif_attach(struct gif_softc *sc)
452 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck,
453 &in_gif_protosw, sc);
454 if (sc->encap_cookie4 == NULL)
460 in_gif_detach(struct gif_softc *sc)
464 error = encap_detach(sc->encap_cookie4);
466 sc->encap_cookie4 = NULL;