FreeBSD/Linux Kernel Cross Reference
sys/netinet/in_gif.c
1 /* $FreeBSD: releng/6.2/sys/netinet/in_gif.c 155104 2006-01-31 15:56:47Z glebius $ */
2 /* $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 itojun Exp $ */
3
4 /*-
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
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.
19 *
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
30 * SUCH DAMAGE.
31 */
32
33 #include "opt_mrouting.h"
34 #include "opt_inet.h"
35 #include "opt_inet6.h"
36
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/socket.h>
40 #include <sys/sockio.h>
41 #include <sys/mbuf.h>
42 #include <sys/errno.h>
43 #include <sys/kernel.h>
44 #include <sys/sysctl.h>
45 #include <sys/protosw.h>
46
47 #include <sys/malloc.h>
48
49 #include <net/if.h>
50 #include <net/route.h>
51
52 #include <netinet/in.h>
53 #include <netinet/in_systm.h>
54 #include <netinet/ip.h>
55 #include <netinet/ip_var.h>
56 #include <netinet/in_gif.h>
57 #include <netinet/in_var.h>
58 #include <netinet/ip_encap.h>
59 #include <netinet/ip_ecn.h>
60
61 #ifdef INET6
62 #include <netinet/ip6.h>
63 #endif
64
65 #ifdef MROUTING
66 #include <netinet/ip_mroute.h>
67 #endif /* MROUTING */
68
69 #include <net/if_gif.h>
70
71 #include <net/net_osdep.h>
72
73 static int gif_validate4(const struct ip *, struct gif_softc *,
74 struct ifnet *);
75
76 extern struct domain inetdomain;
77 struct protosw in_gif_protosw = {
78 .pr_type = SOCK_RAW,
79 .pr_domain = &inetdomain,
80 .pr_protocol = 0/* IPPROTO_IPV[46] */,
81 .pr_flags = PR_ATOMIC|PR_ADDR,
82 .pr_input = in_gif_input,
83 .pr_output = (pr_output_t*)rip_output,
84 .pr_ctloutput = rip_ctloutput,
85 .pr_usrreqs = &rip_usrreqs
86 };
87
88 static int ip_gif_ttl = GIF_TTL;
89 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW,
90 &ip_gif_ttl, 0, "");
91
92 int
93 in_gif_output(ifp, family, m)
94 struct ifnet *ifp;
95 int family;
96 struct mbuf *m;
97 {
98 struct gif_softc *sc = ifp->if_softc;
99 struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst;
100 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc;
101 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst;
102 struct ip iphdr; /* capsule IP header, host byte ordered */
103 struct etherip_header eiphdr;
104 int proto, error;
105 u_int8_t tos;
106
107 GIF_LOCK_ASSERT(sc);
108
109 if (sin_src == NULL || sin_dst == NULL ||
110 sin_src->sin_family != AF_INET ||
111 sin_dst->sin_family != AF_INET) {
112 m_freem(m);
113 return EAFNOSUPPORT;
114 }
115
116 switch (family) {
117 #ifdef INET
118 case AF_INET:
119 {
120 struct ip *ip;
121
122 proto = IPPROTO_IPV4;
123 if (m->m_len < sizeof(*ip)) {
124 m = m_pullup(m, sizeof(*ip));
125 if (!m)
126 return ENOBUFS;
127 }
128 ip = mtod(m, struct ip *);
129 tos = ip->ip_tos;
130 break;
131 }
132 #endif /* INET */
133 #ifdef INET6
134 case AF_INET6:
135 {
136 struct ip6_hdr *ip6;
137 proto = IPPROTO_IPV6;
138 if (m->m_len < sizeof(*ip6)) {
139 m = m_pullup(m, sizeof(*ip6));
140 if (!m)
141 return ENOBUFS;
142 }
143 ip6 = mtod(m, struct ip6_hdr *);
144 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
145 break;
146 }
147 #endif /* INET6 */
148 case AF_LINK:
149 proto = IPPROTO_ETHERIP;
150 eiphdr.eip_ver = ETHERIP_VERSION & ETHERIP_VER_VERS_MASK;
151 eiphdr.eip_pad = 0;
152 /* prepend Ethernet-in-IP header */
153 M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT);
154 if (m && m->m_len < sizeof(struct etherip_header))
155 m = m_pullup(m, sizeof(struct etherip_header));
156 if (m == NULL)
157 return ENOBUFS;
158 bcopy(&eiphdr, mtod(m, struct etherip_header *),
159 sizeof(struct etherip_header));
160 break;
161
162 default:
163 #ifdef DEBUG
164 printf("in_gif_output: warning: unknown family %d passed\n",
165 family);
166 #endif
167 m_freem(m);
168 return EAFNOSUPPORT;
169 }
170
171 bzero(&iphdr, sizeof(iphdr));
172 iphdr.ip_src = sin_src->sin_addr;
173 /* bidirectional configured tunnel mode */
174 if (sin_dst->sin_addr.s_addr != INADDR_ANY)
175 iphdr.ip_dst = sin_dst->sin_addr;
176 else {
177 m_freem(m);
178 return ENETUNREACH;
179 }
180 iphdr.ip_p = proto;
181 /* version will be set in ip_output() */
182 iphdr.ip_ttl = ip_gif_ttl;
183 iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip);
184 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE,
185 &iphdr.ip_tos, &tos);
186
187 /* prepend new IP header */
188 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
189 if (m && m->m_len < sizeof(struct ip))
190 m = m_pullup(m, sizeof(struct ip));
191 if (m == NULL) {
192 printf("ENOBUFS in in_gif_output %d\n", __LINE__);
193 return ENOBUFS;
194 }
195 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip));
196
197 if (dst->sin_family != sin_dst->sin_family ||
198 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) {
199 /* cache route doesn't match */
200 bzero(dst, sizeof(*dst));
201 dst->sin_family = sin_dst->sin_family;
202 dst->sin_len = sizeof(struct sockaddr_in);
203 dst->sin_addr = sin_dst->sin_addr;
204 if (sc->gif_ro.ro_rt) {
205 RTFREE(sc->gif_ro.ro_rt);
206 sc->gif_ro.ro_rt = NULL;
207 }
208 #if 0
209 GIF2IFP(sc)->if_mtu = GIF_MTU;
210 #endif
211 }
212
213 if (sc->gif_ro.ro_rt == NULL) {
214 rtalloc_ign(&sc->gif_ro, 0);
215 if (sc->gif_ro.ro_rt == NULL) {
216 m_freem(m);
217 return ENETUNREACH;
218 }
219
220 /* if it constitutes infinite encapsulation, punt. */
221 if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
222 m_freem(m);
223 return ENETUNREACH; /* XXX */
224 }
225 #if 0
226 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu
227 - sizeof(struct ip);
228 #endif
229 }
230
231 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL);
232
233 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) &&
234 sc->gif_ro.ro_rt != NULL) {
235 RTFREE(sc->gif_ro.ro_rt);
236 sc->gif_ro.ro_rt = NULL;
237 }
238
239 return (error);
240 }
241
242 void
243 in_gif_input(m, off)
244 struct mbuf *m;
245 int off;
246 {
247 struct ifnet *gifp = NULL;
248 struct gif_softc *sc;
249 struct ip *ip;
250 int af;
251 u_int8_t otos;
252 int proto;
253
254 ip = mtod(m, struct ip *);
255 proto = ip->ip_p;
256
257 sc = (struct gif_softc *)encap_getarg(m);
258 if (sc == NULL) {
259 m_freem(m);
260 ipstat.ips_nogif++;
261 return;
262 }
263
264 gifp = GIF2IFP(sc);
265 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
266 m_freem(m);
267 ipstat.ips_nogif++;
268 return;
269 }
270
271 otos = ip->ip_tos;
272 m_adj(m, off);
273
274 switch (proto) {
275 #ifdef INET
276 case IPPROTO_IPV4:
277 {
278 struct ip *ip;
279 af = AF_INET;
280 if (m->m_len < sizeof(*ip)) {
281 m = m_pullup(m, sizeof(*ip));
282 if (!m)
283 return;
284 }
285 ip = mtod(m, struct ip *);
286 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
287 ECN_ALLOWED : ECN_NOCARE,
288 &otos, &ip->ip_tos) == 0) {
289 m_freem(m);
290 return;
291 }
292 break;
293 }
294 #endif
295 #ifdef INET6
296 case IPPROTO_IPV6:
297 {
298 struct ip6_hdr *ip6;
299 u_int8_t itos, oitos;
300
301 af = AF_INET6;
302 if (m->m_len < sizeof(*ip6)) {
303 m = m_pullup(m, sizeof(*ip6));
304 if (!m)
305 return;
306 }
307 ip6 = mtod(m, struct ip6_hdr *);
308 itos = oitos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
309 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
310 ECN_ALLOWED : ECN_NOCARE,
311 &otos, &itos) == 0) {
312 m_freem(m);
313 return;
314 }
315 if (itos != oitos) {
316 ip6->ip6_flow &= ~htonl(0xff << 20);
317 ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
318 }
319 break;
320 }
321 #endif /* INET6 */
322 case IPPROTO_ETHERIP:
323 af = AF_LINK;
324 break;
325
326 default:
327 ipstat.ips_nogif++;
328 m_freem(m);
329 return;
330 }
331 gif_input(m, af, gifp);
332 return;
333 }
334
335 /*
336 * validate outer address.
337 */
338 static int
339 gif_validate4(ip, sc, ifp)
340 const struct ip *ip;
341 struct gif_softc *sc;
342 struct ifnet *ifp;
343 {
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, &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 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL);
380 if (!rt || rt->rt_ifp != ifp) {
381 #if 0
382 log(LOG_WARNING, "%s: packet from 0x%x dropped "
383 "due to ingress filter\n", if_name(GIF2IFP(sc)),
384 (u_int32_t)ntohl(sin.sin_addr.s_addr));
385 #endif
386 if (rt)
387 rtfree(rt);
388 return 0;
389 }
390 rtfree(rt);
391 }
392
393 return 32 * 2;
394 }
395
396 /*
397 * we know that we are in IFF_UP, outer address available, and outer family
398 * matched the physical addr family. see gif_encapcheck().
399 */
400 int
401 gif_encapcheck4(m, off, proto, arg)
402 const struct mbuf *m;
403 int off;
404 int proto;
405 void *arg;
406 {
407 struct ip ip;
408 struct gif_softc *sc;
409 struct ifnet *ifp;
410
411 /* sanity check done in caller */
412 sc = (struct gif_softc *)arg;
413
414 /* LINTED const cast */
415 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip);
416 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
417
418 return gif_validate4(&ip, sc, ifp);
419 }
420
421 int
422 in_gif_attach(sc)
423 struct gif_softc *sc;
424 {
425 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck,
426 &in_gif_protosw, sc);
427 if (sc->encap_cookie4 == NULL)
428 return EEXIST;
429 return 0;
430 }
431
432 int
433 in_gif_detach(sc)
434 struct gif_softc *sc;
435 {
436 int error;
437
438 error = encap_detach(sc->encap_cookie4);
439 if (error == 0)
440 sc->encap_cookie4 = NULL;
441 return error;
442 }
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