if ipv6 doesnt need oldstyle prototypes maybe its time we took them out
[dragonfly.git] / sys / netinet / ip_encap.c
CommitLineData
984263bc 1/* $FreeBSD: src/sys/netinet/ip_encap.c,v 1.1.2.5 2003/01/23 21:06:45 sam Exp $ */
42a7fc75 2/* $DragonFly: src/sys/netinet/ip_encap.c,v 1.4 2003/08/23 11:18:00 rob Exp $ */
984263bc
MD
3/* $KAME: ip_encap.c,v 1.41 2001/03/15 08:35:08 itojun Exp $ */
4
5/*
6 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the project nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33/*
34 * My grandfather said that there's a devil inside tunnelling technology...
35 *
36 * We have surprisingly many protocols that want packets with IP protocol
37 * #4 or #41. Here's a list of protocols that want protocol #41:
38 * RFC1933 configured tunnel
39 * RFC1933 automatic tunnel
40 * RFC2401 IPsec tunnel
41 * RFC2473 IPv6 generic packet tunnelling
42 * RFC2529 6over4 tunnel
43 * mobile-ip6 (uses RFC2473)
44 * RFC3056 6to4 tunnel
45 * isatap tunnel
46 * Here's a list of protocol that want protocol #4:
47 * RFC1853 IPv4-in-IPv4 tunnelling
48 * RFC2003 IPv4 encapsulation within IPv4
49 * RFC2344 reverse tunnelling for mobile-ip4
50 * RFC2401 IPsec tunnel
51 * Well, what can I say. They impose different en/decapsulation mechanism
52 * from each other, so they need separate protocol handler. The only one
53 * we can easily determine by protocol # is IPsec, which always has
54 * AH/ESP/IPComp header right after outer IP header.
55 *
56 * So, clearly good old protosw does not work for protocol #4 and #41.
57 * The code will let you match protocol via src/dst address pair.
58 */
59/* XXX is M_NETADDR correct? */
60
61#include "opt_inet.h"
62#include "opt_inet6.h"
63
64#include <sys/param.h>
65#include <sys/systm.h>
66#include <sys/socket.h>
67#include <sys/sockio.h>
68#include <sys/mbuf.h>
69#include <sys/errno.h>
70#include <sys/protosw.h>
71#include <sys/queue.h>
72
73#include <net/if.h>
74#include <net/route.h>
75
76#include <netinet/in.h>
77#include <netinet/in_systm.h>
78#include <netinet/ip.h>
79#include <netinet/ip_var.h>
80#include <netinet/ip_encap.h>
81#include <netinet/ipprotosw.h>
82
83#ifdef INET6
84#include <netinet/ip6.h>
85#include <netinet6/ip6_var.h>
86#include <netinet6/ip6protosw.h>
87#endif
88
89#include <machine/stdarg.h>
90
91#include <net/net_osdep.h>
92
93#include <sys/kernel.h>
94#include <sys/malloc.h>
95MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure");
96
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97static void encap_add (struct encaptab *);
98static int mask_match (const struct encaptab *, const struct sockaddr *,
99 const struct sockaddr *);
100static void encap_fillarg (struct mbuf *, const struct encaptab *);
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101
102#ifndef LIST_HEAD_INITIALIZER
103/* rely upon BSS initialization */
104LIST_HEAD(, encaptab) encaptab;
105#else
106LIST_HEAD(, encaptab) encaptab = LIST_HEAD_INITIALIZER(&encaptab);
107#endif
108
109void (*ipip_input)(struct mbuf *, int, int); /* hook for mrouting */
110
111void
112encap_init()
113{
114 static int initialized = 0;
115
116 if (initialized)
117 return;
118 initialized++;
119#if 0
120 /*
121 * we cannot use LIST_INIT() here, since drivers may want to call
122 * encap_attach(), on driver attach. encap_init() will be called
123 * on AF_INET{,6} initialization, which happens after driver
124 * initialization - using LIST_INIT() here can nuke encap_attach()
125 * from drivers.
126 */
127 LIST_INIT(&encaptab);
128#endif
129}
130
131#ifdef INET
132void
133encap4_input(struct mbuf *m, int off, int proto)
134{
135 struct ip *ip;
136 struct sockaddr_in s, d;
137 const struct ipprotosw *psw;
138 struct encaptab *ep, *match;
139 int prio, matchprio;
140
141 ip = mtod(m, struct ip *);
142
143 bzero(&s, sizeof(s));
144 s.sin_family = AF_INET;
145 s.sin_len = sizeof(struct sockaddr_in);
146 s.sin_addr = ip->ip_src;
147 bzero(&d, sizeof(d));
148 d.sin_family = AF_INET;
149 d.sin_len = sizeof(struct sockaddr_in);
150 d.sin_addr = ip->ip_dst;
151
152 match = NULL;
153 matchprio = 0;
154 for (ep = LIST_FIRST(&encaptab); ep; ep = LIST_NEXT(ep, chain)) {
155 if (ep->af != AF_INET)
156 continue;
157 if (ep->proto >= 0 && ep->proto != proto)
158 continue;
159 if (ep->func)
160 prio = (*ep->func)(m, off, proto, ep->arg);
161 else {
162 /*
163 * it's inbound traffic, we need to match in reverse
164 * order
165 */
166 prio = mask_match(ep, (struct sockaddr *)&d,
167 (struct sockaddr *)&s);
168 }
169
170 /*
171 * We prioritize the matches by using bit length of the
172 * matches. mask_match() and user-supplied matching function
173 * should return the bit length of the matches (for example,
174 * if both src/dst are matched for IPv4, 64 should be returned).
175 * 0 or negative return value means "it did not match".
176 *
177 * The question is, since we have two "mask" portion, we
178 * cannot really define total order between entries.
179 * For example, which of these should be preferred?
180 * mask_match() returns 48 (32 + 16) for both of them.
181 * src=3ffe::/16, dst=3ffe:501::/32
182 * src=3ffe:501::/32, dst=3ffe::/16
183 *
184 * We need to loop through all the possible candidates
185 * to get the best match - the search takes O(n) for
186 * n attachments (i.e. interfaces).
187 */
188 if (prio <= 0)
189 continue;
190 if (prio > matchprio) {
191 matchprio = prio;
192 match = ep;
193 }
194 }
195
196 if (match) {
197 /* found a match, "match" has the best one */
198 psw = (const struct ipprotosw *)match->psw;
199 if (psw && psw->pr_input) {
200 encap_fillarg(m, match);
201 (*psw->pr_input)(m, off, proto);
202 } else
203 m_freem(m);
204 return;
205 }
206
207 /* for backward compatibility */
208 if (proto == IPPROTO_IPV4 && ipip_input) {
209 ipip_input(m, off, proto);
210 return;
211 }
212
213 /* last resort: inject to raw socket */
214 rip_input(m, off, proto);
215}
216#endif
217
218#ifdef INET6
219int
220encap6_input(mp, offp, proto)
221 struct mbuf **mp;
222 int *offp;
223 int proto;
224{
225 struct mbuf *m = *mp;
226 struct ip6_hdr *ip6;
227 struct sockaddr_in6 s, d;
228 const struct ip6protosw *psw;
229 struct encaptab *ep, *match;
230 int prio, matchprio;
231
232 ip6 = mtod(m, struct ip6_hdr *);
233
234 bzero(&s, sizeof(s));
235 s.sin6_family = AF_INET6;
236 s.sin6_len = sizeof(struct sockaddr_in6);
237 s.sin6_addr = ip6->ip6_src;
238 bzero(&d, sizeof(d));
239 d.sin6_family = AF_INET6;
240 d.sin6_len = sizeof(struct sockaddr_in6);
241 d.sin6_addr = ip6->ip6_dst;
242
243 match = NULL;
244 matchprio = 0;
245 for (ep = LIST_FIRST(&encaptab); ep; ep = LIST_NEXT(ep, chain)) {
246 if (ep->af != AF_INET6)
247 continue;
248 if (ep->proto >= 0 && ep->proto != proto)
249 continue;
250 if (ep->func)
251 prio = (*ep->func)(m, *offp, proto, ep->arg);
252 else {
253 /*
254 * it's inbound traffic, we need to match in reverse
255 * order
256 */
257 prio = mask_match(ep, (struct sockaddr *)&d,
258 (struct sockaddr *)&s);
259 }
260
261 /* see encap4_input() for issues here */
262 if (prio <= 0)
263 continue;
264 if (prio > matchprio) {
265 matchprio = prio;
266 match = ep;
267 }
268 }
269
270 if (match) {
271 /* found a match */
272 psw = (const struct ip6protosw *)match->psw;
273 if (psw && psw->pr_input) {
274 encap_fillarg(m, match);
275 return (*psw->pr_input)(mp, offp, proto);
276 } else {
277 m_freem(m);
278 return IPPROTO_DONE;
279 }
280 }
281
282 /* last resort: inject to raw socket */
283 return rip6_input(mp, offp, proto);
284}
285#endif
286
287static void
288encap_add(ep)
289 struct encaptab *ep;
290{
291
292 LIST_INSERT_HEAD(&encaptab, ep, chain);
293}
294
295/*
296 * sp (src ptr) is always my side, and dp (dst ptr) is always remote side.
297 * length of mask (sm and dm) is assumed to be same as sp/dp.
298 * Return value will be necessary as input (cookie) for encap_detach().
299 */
300const struct encaptab *
301encap_attach(af, proto, sp, sm, dp, dm, psw, arg)
302 int af;
303 int proto;
304 const struct sockaddr *sp, *sm;
305 const struct sockaddr *dp, *dm;
306 const struct protosw *psw;
307 void *arg;
308{
309 struct encaptab *ep;
310 int error;
311 int s;
312
313 s = splnet();
314 /* sanity check on args */
315 if (sp->sa_len > sizeof(ep->src) || dp->sa_len > sizeof(ep->dst)) {
316 error = EINVAL;
317 goto fail;
318 }
319 if (sp->sa_len != dp->sa_len) {
320 error = EINVAL;
321 goto fail;
322 }
323 if (af != sp->sa_family || af != dp->sa_family) {
324 error = EINVAL;
325 goto fail;
326 }
327
328 /* check if anyone have already attached with exactly same config */
329 for (ep = LIST_FIRST(&encaptab); ep; ep = LIST_NEXT(ep, chain)) {
330 if (ep->af != af)
331 continue;
332 if (ep->proto != proto)
333 continue;
334 if (ep->src.ss_len != sp->sa_len ||
335 bcmp(&ep->src, sp, sp->sa_len) != 0 ||
336 bcmp(&ep->srcmask, sm, sp->sa_len) != 0)
337 continue;
338 if (ep->dst.ss_len != dp->sa_len ||
339 bcmp(&ep->dst, dp, dp->sa_len) != 0 ||
340 bcmp(&ep->dstmask, dm, dp->sa_len) != 0)
341 continue;
342
343 error = EEXIST;
344 goto fail;
345 }
346
347 ep = malloc(sizeof(*ep), M_NETADDR, M_NOWAIT); /*XXX*/
348 if (ep == NULL) {
349 error = ENOBUFS;
350 goto fail;
351 }
352 bzero(ep, sizeof(*ep));
353
354 ep->af = af;
355 ep->proto = proto;
356 bcopy(sp, &ep->src, sp->sa_len);
357 bcopy(sm, &ep->srcmask, sp->sa_len);
358 bcopy(dp, &ep->dst, dp->sa_len);
359 bcopy(dm, &ep->dstmask, dp->sa_len);
360 ep->psw = psw;
361 ep->arg = arg;
362
363 encap_add(ep);
364
365 error = 0;
366 splx(s);
367 return ep;
368
369fail:
370 splx(s);
371 return NULL;
372}
373
374const struct encaptab *
375encap_attach_func(af, proto, func, psw, arg)
376 int af;
377 int proto;
42a7fc75 378 int (*func) (const struct mbuf *, int, int, void *);
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379 const struct protosw *psw;
380 void *arg;
381{
382 struct encaptab *ep;
383 int error;
384 int s;
385
386 s = splnet();
387 /* sanity check on args */
388 if (!func) {
389 error = EINVAL;
390 goto fail;
391 }
392
393 ep = malloc(sizeof(*ep), M_NETADDR, M_NOWAIT); /*XXX*/
394 if (ep == NULL) {
395 error = ENOBUFS;
396 goto fail;
397 }
398 bzero(ep, sizeof(*ep));
399
400 ep->af = af;
401 ep->proto = proto;
402 ep->func = func;
403 ep->psw = psw;
404 ep->arg = arg;
405
406 encap_add(ep);
407
408 error = 0;
409 splx(s);
410 return ep;
411
412fail:
413 splx(s);
414 return NULL;
415}
416
417int
418encap_detach(cookie)
419 const struct encaptab *cookie;
420{
421 const struct encaptab *ep = cookie;
422 struct encaptab *p;
423
424 for (p = LIST_FIRST(&encaptab); p; p = LIST_NEXT(p, chain)) {
425 if (p == ep) {
426 LIST_REMOVE(p, chain);
427 free(p, M_NETADDR); /*XXX*/
428 return 0;
429 }
430 }
431
432 return EINVAL;
433}
434
435static int
436mask_match(ep, sp, dp)
437 const struct encaptab *ep;
438 const struct sockaddr *sp;
439 const struct sockaddr *dp;
440{
441 struct sockaddr_storage s;
442 struct sockaddr_storage d;
443 int i;
444 const u_int8_t *p, *q;
445 u_int8_t *r;
446 int matchlen;
447
448 if (sp->sa_len > sizeof(s) || dp->sa_len > sizeof(d))
449 return 0;
450 if (sp->sa_family != ep->af || dp->sa_family != ep->af)
451 return 0;
452 if (sp->sa_len != ep->src.ss_len || dp->sa_len != ep->dst.ss_len)
453 return 0;
454
455 matchlen = 0;
456
457 p = (const u_int8_t *)sp;
458 q = (const u_int8_t *)&ep->srcmask;
459 r = (u_int8_t *)&s;
460 for (i = 0 ; i < sp->sa_len; i++) {
461 r[i] = p[i] & q[i];
462 /* XXX estimate */
463 matchlen += (q[i] ? 8 : 0);
464 }
465
466 p = (const u_int8_t *)dp;
467 q = (const u_int8_t *)&ep->dstmask;
468 r = (u_int8_t *)&d;
469 for (i = 0 ; i < dp->sa_len; i++) {
470 r[i] = p[i] & q[i];
471 /* XXX rough estimate */
472 matchlen += (q[i] ? 8 : 0);
473 }
474
475 /* need to overwrite len/family portion as we don't compare them */
476 s.ss_len = sp->sa_len;
477 s.ss_family = sp->sa_family;
478 d.ss_len = dp->sa_len;
479 d.ss_family = dp->sa_family;
480
481 if (bcmp(&s, &ep->src, ep->src.ss_len) == 0 &&
482 bcmp(&d, &ep->dst, ep->dst.ss_len) == 0) {
483 return matchlen;
484 } else
485 return 0;
486}
487
488static void
489encap_fillarg(m, ep)
490 struct mbuf *m;
491 const struct encaptab *ep;
492{
493 struct m_tag *tag;
494
32082272 495 tag = m_tag_get(PACKET_TAG_ENCAP, sizeof (void*), M_DONTWAIT);
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MD
496 if (tag) {
497 *(void**)(tag+1) = ep->arg;
498 m_tag_prepend(m, tag);
499 }
500}
501
502void *
503encap_getarg(m)
504 struct mbuf *m;
505{
506 void *p = NULL;
507 struct m_tag *tag;
508
509 tag = m_tag_find(m, PACKET_TAG_ENCAP, NULL);
510 if (tag) {
511 p = *(void**)(tag+1);
512 m_tag_delete(m, tag);
513 }
514 return p;
515}