FreeBSD/Linux Kernel Cross Reference
sys/netinet/in_gif.c
1 /* $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 itojun Exp $ */
2
3 /*-
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
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.
18 *
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
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD: src/sys/netinet/in_gif.c,v 1.43 2008/12/02 21:37:28 bz Exp $");
34
35 #include "opt_mrouting.h"
36 #include "opt_inet.h"
37 #include "opt_inet6.h"
38
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/socket.h>
42 #include <sys/sockio.h>
43 #include <sys/mbuf.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>
49 #include <sys/vimage.h>
50
51 #include <net/if.h>
52 #include <net/route.h>
53
54 #include <netinet/in.h>
55 #include <netinet/in_systm.h>
56 #include <netinet/ip.h>
57 #include <netinet/ip_var.h>
58 #include <netinet/in_gif.h>
59 #include <netinet/in_var.h>
60 #include <netinet/ip_encap.h>
61 #include <netinet/ip_ecn.h>
62 #include <netinet/vinet.h>
63
64 #ifdef INET6
65 #include <netinet/ip6.h>
66 #endif
67
68 #ifdef MROUTING
69 #include <netinet/ip_mroute.h>
70 #endif /* MROUTING */
71
72 #include <net/if_gif.h>
73
74 static int gif_validate4(const struct ip *, struct gif_softc *,
75 struct ifnet *);
76
77 extern struct domain inetdomain;
78 struct protosw in_gif_protosw = {
79 .pr_type = SOCK_RAW,
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
87 };
88
89 #ifdef VIMAGE_GLOBALS
90 extern int ip_gif_ttl;
91 #endif
92 SYSCTL_V_INT(V_NET, vnet_gif, _net_inet_ip, IPCTL_GIF_TTL, gifttl,
93 CTLFLAG_RW, ip_gif_ttl, 0, "");
94
95 int
96 in_gif_output(struct ifnet *ifp, int family, struct mbuf *m)
97 {
98 INIT_VNET_GIF(ifp->if_vnet);
99 struct gif_softc *sc = ifp->if_softc;
100 struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst;
101 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc;
102 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst;
103 struct ip iphdr; /* capsule IP header, host byte ordered */
104 struct etherip_header eiphdr;
105 int proto, error;
106 u_int8_t tos;
107
108 GIF_LOCK_ASSERT(sc);
109
110 if (sin_src == NULL || sin_dst == NULL ||
111 sin_src->sin_family != AF_INET ||
112 sin_dst->sin_family != AF_INET) {
113 m_freem(m);
114 return EAFNOSUPPORT;
115 }
116
117 switch (family) {
118 #ifdef INET
119 case AF_INET:
120 {
121 struct ip *ip;
122
123 proto = IPPROTO_IPV4;
124 if (m->m_len < sizeof(*ip)) {
125 m = m_pullup(m, sizeof(*ip));
126 if (!m)
127 return ENOBUFS;
128 }
129 ip = mtod(m, struct ip *);
130 tos = ip->ip_tos;
131 break;
132 }
133 #endif /* INET */
134 #ifdef INET6
135 case AF_INET6:
136 {
137 struct ip6_hdr *ip6;
138 proto = IPPROTO_IPV6;
139 if (m->m_len < sizeof(*ip6)) {
140 m = m_pullup(m, sizeof(*ip6));
141 if (!m)
142 return ENOBUFS;
143 }
144 ip6 = mtod(m, struct ip6_hdr *);
145 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
146 break;
147 }
148 #endif /* INET6 */
149 case AF_LINK:
150 proto = IPPROTO_ETHERIP;
151 eiphdr.eip_ver = ETHERIP_VERSION & ETHERIP_VER_VERS_MASK;
152 eiphdr.eip_pad = 0;
153 /* prepend Ethernet-in-IP header */
154 M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT);
155 if (m && m->m_len < sizeof(struct etherip_header))
156 m = m_pullup(m, sizeof(struct etherip_header));
157 if (m == NULL)
158 return ENOBUFS;
159 bcopy(&eiphdr, mtod(m, struct etherip_header *),
160 sizeof(struct etherip_header));
161 break;
162
163 default:
164 #ifdef DEBUG
165 printf("in_gif_output: warning: unknown family %d passed\n",
166 family);
167 #endif
168 m_freem(m);
169 return EAFNOSUPPORT;
170 }
171
172 bzero(&iphdr, sizeof(iphdr));
173 iphdr.ip_src = sin_src->sin_addr;
174 /* bidirectional configured tunnel mode */
175 if (sin_dst->sin_addr.s_addr != INADDR_ANY)
176 iphdr.ip_dst = sin_dst->sin_addr;
177 else {
178 m_freem(m);
179 return ENETUNREACH;
180 }
181 iphdr.ip_p = proto;
182 /* version will be set in ip_output() */
183 iphdr.ip_ttl = V_ip_gif_ttl;
184 iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip);
185 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE,
186 &iphdr.ip_tos, &tos);
187
188 /* prepend new IP header */
189 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
190 if (m && m->m_len < sizeof(struct ip))
191 m = m_pullup(m, sizeof(struct ip));
192 if (m == NULL) {
193 printf("ENOBUFS in in_gif_output %d\n", __LINE__);
194 return ENOBUFS;
195 }
196 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip));
197
198 M_SETFIB(m, sc->gif_fibnum);
199
200 if (dst->sin_family != sin_dst->sin_family ||
201 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) {
202 /* cache route doesn't match */
203 bzero(dst, sizeof(*dst));
204 dst->sin_family = sin_dst->sin_family;
205 dst->sin_len = sizeof(struct sockaddr_in);
206 dst->sin_addr = sin_dst->sin_addr;
207 if (sc->gif_ro.ro_rt) {
208 RTFREE(sc->gif_ro.ro_rt);
209 sc->gif_ro.ro_rt = NULL;
210 }
211 #if 0
212 GIF2IFP(sc)->if_mtu = GIF_MTU;
213 #endif
214 }
215
216 if (sc->gif_ro.ro_rt == NULL) {
217 in_rtalloc_ign(&sc->gif_ro, 0, sc->gif_fibnum);
218 if (sc->gif_ro.ro_rt == NULL) {
219 m_freem(m);
220 return ENETUNREACH;
221 }
222
223 /* if it constitutes infinite encapsulation, punt. */
224 if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
225 m_freem(m);
226 return ENETUNREACH; /* XXX */
227 }
228 #if 0
229 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu
230 - sizeof(struct ip);
231 #endif
232 }
233
234 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL);
235
236 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) &&
237 sc->gif_ro.ro_rt != NULL) {
238 RTFREE(sc->gif_ro.ro_rt);
239 sc->gif_ro.ro_rt = NULL;
240 }
241
242 return (error);
243 }
244
245 void
246 in_gif_input(struct mbuf *m, int off)
247 {
248 INIT_VNET_INET(curvnet);
249 struct ifnet *gifp = NULL;
250 struct gif_softc *sc;
251 struct ip *ip;
252 int af;
253 u_int8_t otos;
254 int proto;
255
256 ip = mtod(m, struct ip *);
257 proto = ip->ip_p;
258
259 sc = (struct gif_softc *)encap_getarg(m);
260 if (sc == NULL) {
261 m_freem(m);
262 V_ipstat.ips_nogif++;
263 return;
264 }
265
266 gifp = GIF2IFP(sc);
267 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
268 m_freem(m);
269 V_ipstat.ips_nogif++;
270 return;
271 }
272
273 otos = ip->ip_tos;
274 m_adj(m, off);
275
276 switch (proto) {
277 #ifdef INET
278 case IPPROTO_IPV4:
279 {
280 struct ip *ip;
281 af = AF_INET;
282 if (m->m_len < sizeof(*ip)) {
283 m = m_pullup(m, sizeof(*ip));
284 if (!m)
285 return;
286 }
287 ip = mtod(m, struct ip *);
288 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
289 ECN_ALLOWED : ECN_NOCARE,
290 &otos, &ip->ip_tos) == 0) {
291 m_freem(m);
292 return;
293 }
294 break;
295 }
296 #endif
297 #ifdef INET6
298 case IPPROTO_IPV6:
299 {
300 struct ip6_hdr *ip6;
301 u_int8_t itos, oitos;
302
303 af = AF_INET6;
304 if (m->m_len < sizeof(*ip6)) {
305 m = m_pullup(m, sizeof(*ip6));
306 if (!m)
307 return;
308 }
309 ip6 = mtod(m, struct ip6_hdr *);
310 itos = oitos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
311 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
312 ECN_ALLOWED : ECN_NOCARE,
313 &otos, &itos) == 0) {
314 m_freem(m);
315 return;
316 }
317 if (itos != oitos) {
318 ip6->ip6_flow &= ~htonl(0xff << 20);
319 ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
320 }
321 break;
322 }
323 #endif /* INET6 */
324 case IPPROTO_ETHERIP:
325 af = AF_LINK;
326 break;
327
328 default:
329 V_ipstat.ips_nogif++;
330 m_freem(m);
331 return;
332 }
333 gif_input(m, af, gifp);
334 return;
335 }
336
337 /*
338 * validate outer address.
339 */
340 static int
341 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp)
342 {
343 INIT_VNET_INET(curvnet);
344 struct sockaddr_in *src, *dst;
345 struct in_ifaddr *ia4;
346
347 src = (struct sockaddr_in *)sc->gif_psrc;
348 dst = (struct sockaddr_in *)sc->gif_pdst;
349
350 /* check for address match */
351 if (src->sin_addr.s_addr != ip->ip_dst.s_addr ||
352 dst->sin_addr.s_addr != ip->ip_src.s_addr)
353 return 0;
354
355 /* martian filters on outer source - NOT done in ip_input! */
356 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr)))
357 return 0;
358 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) {
359 case 0: case 127: case 255:
360 return 0;
361 }
362 /* reject packets with broadcast on source */
363 TAILQ_FOREACH(ia4, &V_in_ifaddrhead, ia_link) {
364 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0)
365 continue;
366 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr)
367 return 0;
368 }
369
370 /* ingress filters on outer source */
371 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) {
372 struct sockaddr_in sin;
373 struct rtentry *rt;
374
375 bzero(&sin, sizeof(sin));
376 sin.sin_family = AF_INET;
377 sin.sin_len = sizeof(struct sockaddr_in);
378 sin.sin_addr = ip->ip_src;
379 /* XXX MRT check for the interface we would use on output */
380 rt = in_rtalloc1((struct sockaddr *)&sin, 0,
381 0UL, sc->gif_fibnum);
382 if (!rt || rt->rt_ifp != ifp) {
383 #if 0
384 log(LOG_WARNING, "%s: packet from 0x%x dropped "
385 "due to ingress filter\n", if_name(GIF2IFP(sc)),
386 (u_int32_t)ntohl(sin.sin_addr.s_addr));
387 #endif
388 if (rt)
389 RTFREE_LOCKED(rt);
390 return 0;
391 }
392 RTFREE_LOCKED(rt);
393 }
394
395 return 32 * 2;
396 }
397
398 /*
399 * we know that we are in IFF_UP, outer address available, and outer family
400 * matched the physical addr family. see gif_encapcheck().
401 */
402 int
403 gif_encapcheck4(const struct mbuf *m, int off, int proto, void *arg)
404 {
405 struct ip ip;
406 struct gif_softc *sc;
407 struct ifnet *ifp;
408
409 /* sanity check done in caller */
410 sc = (struct gif_softc *)arg;
411
412 /* LINTED const cast */
413 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip);
414 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
415
416 return gif_validate4(&ip, sc, ifp);
417 }
418
419 int
420 in_gif_attach(struct gif_softc *sc)
421 {
422 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck,
423 &in_gif_protosw, sc);
424 if (sc->encap_cookie4 == NULL)
425 return EEXIST;
426 return 0;
427 }
428
429 int
430 in_gif_detach(struct gif_softc *sc)
431 {
432 int error;
433
434 error = encap_detach(sc->encap_cookie4);
435 if (error == 0)
436 sc->encap_cookie4 = NULL;
437 return error;
438 }
439
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