FreeBSD/Linux Kernel Cross Reference
sys/netinet/in_gif.c
1 /* $FreeBSD$ */
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 error, len, proto;
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 len = sizeof(struct ip);
189 #ifndef __NO_STRICT_ALIGNMENT
190 if (family == AF_LINK)
191 len += ETHERIP_ALIGN;
192 #endif
193 M_PREPEND(m, len, M_DONTWAIT);
194 if (m != NULL && m->m_len < len)
195 m = m_pullup(m, len);
196 if (m == NULL) {
197 printf("ENOBUFS in in_gif_output %d\n", __LINE__);
198 return ENOBUFS;
199 }
200 #ifndef __NO_STRICT_ALIGNMENT
201 if (family == AF_LINK) {
202 len = mtod(m, vm_offset_t) & 3;
203 KASSERT(len == 0 || len == ETHERIP_ALIGN,
204 ("in_gif_output: unexpected misalignment"));
205 m->m_data += len;
206 m->m_len -= ETHERIP_ALIGN;
207 }
208 #endif
209 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip));
210
211 if (dst->sin_family != sin_dst->sin_family ||
212 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) {
213 /* cache route doesn't match */
214 bzero(dst, sizeof(*dst));
215 dst->sin_family = sin_dst->sin_family;
216 dst->sin_len = sizeof(struct sockaddr_in);
217 dst->sin_addr = sin_dst->sin_addr;
218 if (sc->gif_ro.ro_rt) {
219 RTFREE(sc->gif_ro.ro_rt);
220 sc->gif_ro.ro_rt = NULL;
221 }
222 #if 0
223 GIF2IFP(sc)->if_mtu = GIF_MTU;
224 #endif
225 }
226
227 if (sc->gif_ro.ro_rt == NULL) {
228 rtalloc_ign(&sc->gif_ro, 0);
229 if (sc->gif_ro.ro_rt == NULL) {
230 m_freem(m);
231 return ENETUNREACH;
232 }
233
234 /* if it constitutes infinite encapsulation, punt. */
235 if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
236 m_freem(m);
237 return ENETUNREACH; /* XXX */
238 }
239 #if 0
240 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu
241 - sizeof(struct ip);
242 #endif
243 }
244
245 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL);
246
247 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) &&
248 sc->gif_ro.ro_rt != NULL) {
249 RTFREE(sc->gif_ro.ro_rt);
250 sc->gif_ro.ro_rt = NULL;
251 }
252
253 return (error);
254 }
255
256 void
257 in_gif_input(m, off)
258 struct mbuf *m;
259 int off;
260 {
261 struct ifnet *gifp = NULL;
262 struct gif_softc *sc;
263 struct ip *ip;
264 int af;
265 u_int8_t otos;
266 int proto;
267
268 ip = mtod(m, struct ip *);
269 proto = ip->ip_p;
270
271 sc = (struct gif_softc *)encap_getarg(m);
272 if (sc == NULL) {
273 m_freem(m);
274 ipstat.ips_nogif++;
275 return;
276 }
277
278 gifp = GIF2IFP(sc);
279 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
280 m_freem(m);
281 ipstat.ips_nogif++;
282 return;
283 }
284
285 otos = ip->ip_tos;
286 m_adj(m, off);
287
288 switch (proto) {
289 #ifdef INET
290 case IPPROTO_IPV4:
291 {
292 struct ip *ip;
293 af = AF_INET;
294 if (m->m_len < sizeof(*ip)) {
295 m = m_pullup(m, sizeof(*ip));
296 if (!m)
297 return;
298 }
299 ip = mtod(m, struct ip *);
300 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
301 ECN_ALLOWED : ECN_NOCARE,
302 &otos, &ip->ip_tos) == 0) {
303 m_freem(m);
304 return;
305 }
306 break;
307 }
308 #endif
309 #ifdef INET6
310 case IPPROTO_IPV6:
311 {
312 struct ip6_hdr *ip6;
313 u_int8_t itos, oitos;
314
315 af = AF_INET6;
316 if (m->m_len < sizeof(*ip6)) {
317 m = m_pullup(m, sizeof(*ip6));
318 if (!m)
319 return;
320 }
321 ip6 = mtod(m, struct ip6_hdr *);
322 itos = oitos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
323 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
324 ECN_ALLOWED : ECN_NOCARE,
325 &otos, &itos) == 0) {
326 m_freem(m);
327 return;
328 }
329 if (itos != oitos) {
330 ip6->ip6_flow &= ~htonl(0xff << 20);
331 ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
332 }
333 break;
334 }
335 #endif /* INET6 */
336 case IPPROTO_ETHERIP:
337 af = AF_LINK;
338 break;
339
340 default:
341 ipstat.ips_nogif++;
342 m_freem(m);
343 return;
344 }
345 gif_input(m, af, gifp);
346 return;
347 }
348
349 /*
350 * validate outer address.
351 */
352 static int
353 gif_validate4(ip, sc, ifp)
354 const struct ip *ip;
355 struct gif_softc *sc;
356 struct ifnet *ifp;
357 {
358 struct sockaddr_in *src, *dst;
359 struct in_ifaddr *ia4;
360
361 src = (struct sockaddr_in *)sc->gif_psrc;
362 dst = (struct sockaddr_in *)sc->gif_pdst;
363
364 /* check for address match */
365 if (src->sin_addr.s_addr != ip->ip_dst.s_addr ||
366 dst->sin_addr.s_addr != ip->ip_src.s_addr)
367 return 0;
368
369 /* martian filters on outer source - NOT done in ip_input! */
370 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr)))
371 return 0;
372 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) {
373 case 0: case 127: case 255:
374 return 0;
375 }
376 /* reject packets with broadcast on source */
377 TAILQ_FOREACH(ia4, &in_ifaddrhead, ia_link) {
378 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0)
379 continue;
380 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr)
381 return 0;
382 }
383
384 /* ingress filters on outer source */
385 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) {
386 struct sockaddr_in sin;
387 struct rtentry *rt;
388
389 bzero(&sin, sizeof(sin));
390 sin.sin_family = AF_INET;
391 sin.sin_len = sizeof(struct sockaddr_in);
392 sin.sin_addr = ip->ip_src;
393 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL);
394 if (!rt || rt->rt_ifp != ifp) {
395 #if 0
396 log(LOG_WARNING, "%s: packet from 0x%x dropped "
397 "due to ingress filter\n", if_name(GIF2IFP(sc)),
398 (u_int32_t)ntohl(sin.sin_addr.s_addr));
399 #endif
400 if (rt)
401 RTFREE_LOCKED(rt);
402 return 0;
403 }
404 RTFREE_LOCKED(rt);
405 }
406
407 return 32 * 2;
408 }
409
410 /*
411 * we know that we are in IFF_UP, outer address available, and outer family
412 * matched the physical addr family. see gif_encapcheck().
413 */
414 int
415 gif_encapcheck4(m, off, proto, arg)
416 const struct mbuf *m;
417 int off;
418 int proto;
419 void *arg;
420 {
421 struct ip ip;
422 struct gif_softc *sc;
423 struct ifnet *ifp;
424
425 /* sanity check done in caller */
426 sc = (struct gif_softc *)arg;
427
428 /* LINTED const cast */
429 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip);
430 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
431
432 return gif_validate4(&ip, sc, ifp);
433 }
434
435 int
436 in_gif_attach(sc)
437 struct gif_softc *sc;
438 {
439 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck,
440 &in_gif_protosw, sc);
441 if (sc->encap_cookie4 == NULL)
442 return EEXIST;
443 return 0;
444 }
445
446 int
447 in_gif_detach(sc)
448 struct gif_softc *sc;
449 {
450 int error;
451
452 error = encap_detach(sc->encap_cookie4);
453 if (error == 0)
454 sc->encap_cookie4 = NULL;
455 return error;
456 }
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