FreeBSD/Linux Kernel Cross Reference
sys/netinet/in_gif.c
1 /* $FreeBSD: releng/5.2/sys/netinet/in_gif.c 121684 2003-10-29 15:07:04Z ume $ */
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 { SOCK_RAW, &inetdomain, 0/* IPPROTO_IPV[46] */, PR_ATOMIC|PR_ADDR,
79 in_gif_input, (pr_output_t*)rip_output, 0, rip_ctloutput,
80 0,
81 0, 0, 0, 0,
82 &rip_usrreqs
83 };
84
85 static int ip_gif_ttl = GIF_TTL;
86 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW,
87 &ip_gif_ttl, 0, "");
88
89 int
90 in_gif_output(ifp, family, m)
91 struct ifnet *ifp;
92 int family;
93 struct mbuf *m;
94 {
95 struct gif_softc *sc = (struct gif_softc*)ifp;
96 struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst;
97 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc;
98 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst;
99 struct ip iphdr; /* capsule IP header, host byte ordered */
100 int proto, error;
101 u_int8_t tos;
102
103 if (sin_src == NULL || sin_dst == NULL ||
104 sin_src->sin_family != AF_INET ||
105 sin_dst->sin_family != AF_INET) {
106 m_freem(m);
107 return EAFNOSUPPORT;
108 }
109
110 switch (family) {
111 #ifdef INET
112 case AF_INET:
113 {
114 struct ip *ip;
115
116 proto = IPPROTO_IPV4;
117 if (m->m_len < sizeof(*ip)) {
118 m = m_pullup(m, sizeof(*ip));
119 if (!m)
120 return ENOBUFS;
121 }
122 ip = mtod(m, struct ip *);
123 tos = ip->ip_tos;
124 break;
125 }
126 #endif /* INET */
127 #ifdef INET6
128 case AF_INET6:
129 {
130 struct ip6_hdr *ip6;
131 proto = IPPROTO_IPV6;
132 if (m->m_len < sizeof(*ip6)) {
133 m = m_pullup(m, sizeof(*ip6));
134 if (!m)
135 return ENOBUFS;
136 }
137 ip6 = mtod(m, struct ip6_hdr *);
138 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
139 break;
140 }
141 #endif /* INET6 */
142 default:
143 #ifdef DEBUG
144 printf("in_gif_output: warning: unknown family %d passed\n",
145 family);
146 #endif
147 m_freem(m);
148 return EAFNOSUPPORT;
149 }
150
151 bzero(&iphdr, sizeof(iphdr));
152 iphdr.ip_src = sin_src->sin_addr;
153 /* bidirectional configured tunnel mode */
154 if (sin_dst->sin_addr.s_addr != INADDR_ANY)
155 iphdr.ip_dst = sin_dst->sin_addr;
156 else {
157 m_freem(m);
158 return ENETUNREACH;
159 }
160 iphdr.ip_p = proto;
161 /* version will be set in ip_output() */
162 iphdr.ip_ttl = ip_gif_ttl;
163 iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip);
164 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE,
165 &iphdr.ip_tos, &tos);
166
167 /* prepend new IP header */
168 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
169 if (m && m->m_len < sizeof(struct ip))
170 m = m_pullup(m, sizeof(struct ip));
171 if (m == NULL) {
172 printf("ENOBUFS in in_gif_output %d\n", __LINE__);
173 return ENOBUFS;
174 }
175 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip));
176
177 if (dst->sin_family != sin_dst->sin_family ||
178 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) {
179 /* cache route doesn't match */
180 dst->sin_family = sin_dst->sin_family;
181 dst->sin_len = sizeof(struct sockaddr_in);
182 dst->sin_addr = sin_dst->sin_addr;
183 if (sc->gif_ro.ro_rt) {
184 RTFREE(sc->gif_ro.ro_rt);
185 sc->gif_ro.ro_rt = NULL;
186 }
187 #if 0
188 sc->gif_if.if_mtu = GIF_MTU;
189 #endif
190 }
191
192 if (sc->gif_ro.ro_rt == NULL) {
193 rtalloc(&sc->gif_ro);
194 if (sc->gif_ro.ro_rt == NULL) {
195 m_freem(m);
196 return ENETUNREACH;
197 }
198
199 /* if it constitutes infinite encapsulation, punt. */
200 if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
201 m_freem(m);
202 return ENETUNREACH; /* XXX */
203 }
204 #if 0
205 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu
206 - sizeof(struct ip);
207 #endif
208 }
209
210 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL);
211 return (error);
212 }
213
214 void
215 in_gif_input(m, off)
216 struct mbuf *m;
217 int off;
218 {
219 struct ifnet *gifp = NULL;
220 struct ip *ip;
221 int af;
222 u_int8_t otos;
223 int proto;
224
225 ip = mtod(m, struct ip *);
226 proto = ip->ip_p;
227
228 gifp = (struct ifnet *)encap_getarg(m);
229
230 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
231 m_freem(m);
232 ipstat.ips_nogif++;
233 return;
234 }
235
236 otos = ip->ip_tos;
237 m_adj(m, off);
238
239 switch (proto) {
240 #ifdef INET
241 case IPPROTO_IPV4:
242 {
243 struct ip *ip;
244 af = AF_INET;
245 if (m->m_len < sizeof(*ip)) {
246 m = m_pullup(m, sizeof(*ip));
247 if (!m)
248 return;
249 }
250 ip = mtod(m, struct ip *);
251 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
252 ECN_ALLOWED : ECN_NOCARE,
253 &otos, &ip->ip_tos) == 0) {
254 m_freem(m);
255 return;
256 }
257 break;
258 }
259 #endif
260 #ifdef INET6
261 case IPPROTO_IPV6:
262 {
263 struct ip6_hdr *ip6;
264 u_int8_t itos, oitos;
265
266 af = AF_INET6;
267 if (m->m_len < sizeof(*ip6)) {
268 m = m_pullup(m, sizeof(*ip6));
269 if (!m)
270 return;
271 }
272 ip6 = mtod(m, struct ip6_hdr *);
273 itos = oitos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
274 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ?
275 ECN_ALLOWED : ECN_NOCARE,
276 &otos, &itos) == 0) {
277 m_freem(m);
278 return;
279 }
280 if (itos != oitos) {
281 ip6->ip6_flow &= ~htonl(0xff << 20);
282 ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
283 }
284 break;
285 }
286 #endif /* INET6 */
287 default:
288 ipstat.ips_nogif++;
289 m_freem(m);
290 return;
291 }
292 gif_input(m, af, gifp);
293 return;
294 }
295
296 /*
297 * validate outer address.
298 */
299 static int
300 gif_validate4(ip, sc, ifp)
301 const struct ip *ip;
302 struct gif_softc *sc;
303 struct ifnet *ifp;
304 {
305 struct sockaddr_in *src, *dst;
306 struct in_ifaddr *ia4;
307
308 src = (struct sockaddr_in *)sc->gif_psrc;
309 dst = (struct sockaddr_in *)sc->gif_pdst;
310
311 /* check for address match */
312 if (src->sin_addr.s_addr != ip->ip_dst.s_addr ||
313 dst->sin_addr.s_addr != ip->ip_src.s_addr)
314 return 0;
315
316 /* martian filters on outer source - NOT done in ip_input! */
317 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr)))
318 return 0;
319 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) {
320 case 0: case 127: case 255:
321 return 0;
322 }
323 /* reject packets with broadcast on source */
324 TAILQ_FOREACH(ia4, &in_ifaddrhead, ia_link) {
325 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0)
326 continue;
327 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr)
328 return 0;
329 }
330
331 /* ingress filters on outer source */
332 if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) {
333 struct sockaddr_in sin;
334 struct rtentry *rt;
335
336 bzero(&sin, sizeof(sin));
337 sin.sin_family = AF_INET;
338 sin.sin_len = sizeof(struct sockaddr_in);
339 sin.sin_addr = ip->ip_src;
340 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL);
341 if (!rt || rt->rt_ifp != ifp) {
342 #if 0
343 log(LOG_WARNING, "%s: packet from 0x%x dropped "
344 "due to ingress filter\n", if_name(&sc->gif_if),
345 (u_int32_t)ntohl(sin.sin_addr.s_addr));
346 #endif
347 if (rt)
348 rtfree(rt);
349 return 0;
350 }
351 rtfree(rt);
352 }
353
354 return 32 * 2;
355 }
356
357 /*
358 * we know that we are in IFF_UP, outer address available, and outer family
359 * matched the physical addr family. see gif_encapcheck().
360 */
361 int
362 gif_encapcheck4(m, off, proto, arg)
363 const struct mbuf *m;
364 int off;
365 int proto;
366 void *arg;
367 {
368 struct ip ip;
369 struct gif_softc *sc;
370 struct ifnet *ifp;
371
372 /* sanity check done in caller */
373 sc = (struct gif_softc *)arg;
374
375 /* LINTED const cast */
376 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip);
377 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
378
379 return gif_validate4(&ip, sc, ifp);
380 }
381
382 int
383 in_gif_attach(sc)
384 struct gif_softc *sc;
385 {
386 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck,
387 &in_gif_protosw, sc);
388 if (sc->encap_cookie4 == NULL)
389 return EEXIST;
390 return 0;
391 }
392
393 int
394 in_gif_detach(sc)
395 struct gif_softc *sc;
396 {
397 int error;
398
399 error = encap_detach(sc->encap_cookie4);
400 if (error == 0)
401 sc->encap_cookie4 = NULL;
402 return error;
403 }
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