Remove struct ipprotosw. It's identical to protosw, so use the generic
[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 $ */
4468b0b4 2/* $DragonFly: src/sys/netinet/ip_encap.c,v 1.9 2004/11/30 19:21:26 joerg 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>
984263bc
MD
81
82#ifdef INET6
83#include <netinet/ip6.h>
84#include <netinet6/ip6_var.h>
85#include <netinet6/ip6protosw.h>
86#endif
87
88#include <machine/stdarg.h>
89
90#include <net/net_osdep.h>
91
92#include <sys/kernel.h>
93#include <sys/malloc.h>
94MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure");
95
42a7fc75
RG
96static void encap_add (struct encaptab *);
97static int mask_match (const struct encaptab *, const struct sockaddr *,
98 const struct sockaddr *);
99static void encap_fillarg (struct mbuf *, const struct encaptab *);
984263bc
MD
100
101#ifndef LIST_HEAD_INITIALIZER
102/* rely upon BSS initialization */
103LIST_HEAD(, encaptab) encaptab;
104#else
105LIST_HEAD(, encaptab) encaptab = LIST_HEAD_INITIALIZER(&encaptab);
106#endif
107
108void (*ipip_input)(struct mbuf *, int, int); /* hook for mrouting */
109
110void
111encap_init()
112{
113 static int initialized = 0;
114
115 if (initialized)
116 return;
117 initialized++;
118#if 0
119 /*
120 * we cannot use LIST_INIT() here, since drivers may want to call
121 * encap_attach(), on driver attach. encap_init() will be called
122 * on AF_INET{,6} initialization, which happens after driver
123 * initialization - using LIST_INIT() here can nuke encap_attach()
124 * from drivers.
125 */
126 LIST_INIT(&encaptab);
127#endif
128}
129
130#ifdef INET
131void
a00138cb 132encap4_input(struct mbuf *m, ...)
984263bc 133{
a00138cb 134 int off, proto;
984263bc
MD
135 struct ip *ip;
136 struct sockaddr_in s, d;
4468b0b4 137 const struct protosw *psw;
984263bc
MD
138 struct encaptab *ep, *match;
139 int prio, matchprio;
a00138cb
JS
140 __va_list ap;
141
142 __va_start(ap, m);
143 off = __va_arg(ap, int);
144 proto = __va_arg(ap, int);
145 __va_end(ap);
984263bc
MD
146
147 ip = mtod(m, struct ip *);
148
149 bzero(&s, sizeof(s));
150 s.sin_family = AF_INET;
151 s.sin_len = sizeof(struct sockaddr_in);
152 s.sin_addr = ip->ip_src;
153 bzero(&d, sizeof(d));
154 d.sin_family = AF_INET;
155 d.sin_len = sizeof(struct sockaddr_in);
156 d.sin_addr = ip->ip_dst;
157
158 match = NULL;
159 matchprio = 0;
160 for (ep = LIST_FIRST(&encaptab); ep; ep = LIST_NEXT(ep, chain)) {
161 if (ep->af != AF_INET)
162 continue;
163 if (ep->proto >= 0 && ep->proto != proto)
164 continue;
165 if (ep->func)
166 prio = (*ep->func)(m, off, proto, ep->arg);
167 else {
168 /*
169 * it's inbound traffic, we need to match in reverse
170 * order
171 */
172 prio = mask_match(ep, (struct sockaddr *)&d,
173 (struct sockaddr *)&s);
174 }
175
176 /*
177 * We prioritize the matches by using bit length of the
178 * matches. mask_match() and user-supplied matching function
179 * should return the bit length of the matches (for example,
180 * if both src/dst are matched for IPv4, 64 should be returned).
181 * 0 or negative return value means "it did not match".
182 *
183 * The question is, since we have two "mask" portion, we
184 * cannot really define total order between entries.
185 * For example, which of these should be preferred?
186 * mask_match() returns 48 (32 + 16) for both of them.
187 * src=3ffe::/16, dst=3ffe:501::/32
188 * src=3ffe:501::/32, dst=3ffe::/16
189 *
190 * We need to loop through all the possible candidates
191 * to get the best match - the search takes O(n) for
192 * n attachments (i.e. interfaces).
193 */
194 if (prio <= 0)
195 continue;
196 if (prio > matchprio) {
197 matchprio = prio;
198 match = ep;
199 }
200 }
201
202 if (match) {
203 /* found a match, "match" has the best one */
4468b0b4 204 psw = match->psw;
984263bc
MD
205 if (psw && psw->pr_input) {
206 encap_fillarg(m, match);
207 (*psw->pr_input)(m, off, proto);
208 } else
209 m_freem(m);
210 return;
211 }
212
213 /* for backward compatibility */
214 if (proto == IPPROTO_IPV4 && ipip_input) {
215 ipip_input(m, off, proto);
216 return;
217 }
218
219 /* last resort: inject to raw socket */
220 rip_input(m, off, proto);
221}
222#endif
223
224#ifdef INET6
225int
226encap6_input(mp, offp, proto)
227 struct mbuf **mp;
228 int *offp;
229 int proto;
230{
231 struct mbuf *m = *mp;
232 struct ip6_hdr *ip6;
233 struct sockaddr_in6 s, d;
234 const struct ip6protosw *psw;
235 struct encaptab *ep, *match;
236 int prio, matchprio;
237
238 ip6 = mtod(m, struct ip6_hdr *);
239
240 bzero(&s, sizeof(s));
241 s.sin6_family = AF_INET6;
242 s.sin6_len = sizeof(struct sockaddr_in6);
243 s.sin6_addr = ip6->ip6_src;
244 bzero(&d, sizeof(d));
245 d.sin6_family = AF_INET6;
246 d.sin6_len = sizeof(struct sockaddr_in6);
247 d.sin6_addr = ip6->ip6_dst;
248
249 match = NULL;
250 matchprio = 0;
251 for (ep = LIST_FIRST(&encaptab); ep; ep = LIST_NEXT(ep, chain)) {
252 if (ep->af != AF_INET6)
253 continue;
254 if (ep->proto >= 0 && ep->proto != proto)
255 continue;
256 if (ep->func)
257 prio = (*ep->func)(m, *offp, proto, ep->arg);
258 else {
259 /*
260 * it's inbound traffic, we need to match in reverse
261 * order
262 */
263 prio = mask_match(ep, (struct sockaddr *)&d,
264 (struct sockaddr *)&s);
265 }
266
267 /* see encap4_input() for issues here */
268 if (prio <= 0)
269 continue;
270 if (prio > matchprio) {
271 matchprio = prio;
272 match = ep;
273 }
274 }
275
276 if (match) {
277 /* found a match */
278 psw = (const struct ip6protosw *)match->psw;
279 if (psw && psw->pr_input) {
280 encap_fillarg(m, match);
281 return (*psw->pr_input)(mp, offp, proto);
282 } else {
283 m_freem(m);
284 return IPPROTO_DONE;
285 }
286 }
287
288 /* last resort: inject to raw socket */
289 return rip6_input(mp, offp, proto);
290}
291#endif
292
293static void
294encap_add(ep)
295 struct encaptab *ep;
296{
297
298 LIST_INSERT_HEAD(&encaptab, ep, chain);
299}
300
301/*
302 * sp (src ptr) is always my side, and dp (dst ptr) is always remote side.
303 * length of mask (sm and dm) is assumed to be same as sp/dp.
304 * Return value will be necessary as input (cookie) for encap_detach().
305 */
306const struct encaptab *
307encap_attach(af, proto, sp, sm, dp, dm, psw, arg)
308 int af;
309 int proto;
310 const struct sockaddr *sp, *sm;
311 const struct sockaddr *dp, *dm;
312 const struct protosw *psw;
313 void *arg;
314{
315 struct encaptab *ep;
316 int error;
317 int s;
318
319 s = splnet();
320 /* sanity check on args */
321 if (sp->sa_len > sizeof(ep->src) || dp->sa_len > sizeof(ep->dst)) {
322 error = EINVAL;
323 goto fail;
324 }
325 if (sp->sa_len != dp->sa_len) {
326 error = EINVAL;
327 goto fail;
328 }
329 if (af != sp->sa_family || af != dp->sa_family) {
330 error = EINVAL;
331 goto fail;
332 }
333
334 /* check if anyone have already attached with exactly same config */
335 for (ep = LIST_FIRST(&encaptab); ep; ep = LIST_NEXT(ep, chain)) {
336 if (ep->af != af)
337 continue;
338 if (ep->proto != proto)
339 continue;
340 if (ep->src.ss_len != sp->sa_len ||
341 bcmp(&ep->src, sp, sp->sa_len) != 0 ||
342 bcmp(&ep->srcmask, sm, sp->sa_len) != 0)
343 continue;
344 if (ep->dst.ss_len != dp->sa_len ||
345 bcmp(&ep->dst, dp, dp->sa_len) != 0 ||
346 bcmp(&ep->dstmask, dm, dp->sa_len) != 0)
347 continue;
348
349 error = EEXIST;
350 goto fail;
351 }
352
ba4e3dbe 353 ep = malloc(sizeof(*ep), M_NETADDR, M_INTWAIT | M_ZERO | M_NULLOK);
984263bc
MD
354 if (ep == NULL) {
355 error = ENOBUFS;
356 goto fail;
357 }
984263bc
MD
358
359 ep->af = af;
360 ep->proto = proto;
361 bcopy(sp, &ep->src, sp->sa_len);
362 bcopy(sm, &ep->srcmask, sp->sa_len);
363 bcopy(dp, &ep->dst, dp->sa_len);
364 bcopy(dm, &ep->dstmask, dp->sa_len);
365 ep->psw = psw;
366 ep->arg = arg;
367
368 encap_add(ep);
369
370 error = 0;
371 splx(s);
372 return ep;
373
374fail:
375 splx(s);
376 return NULL;
377}
378
379const struct encaptab *
380encap_attach_func(af, proto, func, psw, arg)
381 int af;
382 int proto;
42a7fc75 383 int (*func) (const struct mbuf *, int, int, void *);
984263bc
MD
384 const struct protosw *psw;
385 void *arg;
386{
387 struct encaptab *ep;
388 int error;
389 int s;
390
391 s = splnet();
392 /* sanity check on args */
393 if (!func) {
394 error = EINVAL;
395 goto fail;
396 }
397
70f80bec 398 ep = malloc(sizeof(*ep), M_NETADDR, M_INTWAIT | M_ZERO | M_NULLOK);
984263bc
MD
399 if (ep == NULL) {
400 error = ENOBUFS;
401 goto fail;
402 }
984263bc
MD
403
404 ep->af = af;
405 ep->proto = proto;
406 ep->func = func;
407 ep->psw = psw;
408 ep->arg = arg;
409
410 encap_add(ep);
411
412 error = 0;
413 splx(s);
414 return ep;
415
416fail:
417 splx(s);
418 return NULL;
419}
420
421int
422encap_detach(cookie)
423 const struct encaptab *cookie;
424{
425 const struct encaptab *ep = cookie;
426 struct encaptab *p;
427
428 for (p = LIST_FIRST(&encaptab); p; p = LIST_NEXT(p, chain)) {
429 if (p == ep) {
430 LIST_REMOVE(p, chain);
431 free(p, M_NETADDR); /*XXX*/
432 return 0;
433 }
434 }
435
436 return EINVAL;
437}
438
439static int
440mask_match(ep, sp, dp)
441 const struct encaptab *ep;
442 const struct sockaddr *sp;
443 const struct sockaddr *dp;
444{
445 struct sockaddr_storage s;
446 struct sockaddr_storage d;
447 int i;
448 const u_int8_t *p, *q;
449 u_int8_t *r;
450 int matchlen;
451
452 if (sp->sa_len > sizeof(s) || dp->sa_len > sizeof(d))
453 return 0;
454 if (sp->sa_family != ep->af || dp->sa_family != ep->af)
455 return 0;
456 if (sp->sa_len != ep->src.ss_len || dp->sa_len != ep->dst.ss_len)
457 return 0;
458
459 matchlen = 0;
460
461 p = (const u_int8_t *)sp;
462 q = (const u_int8_t *)&ep->srcmask;
463 r = (u_int8_t *)&s;
464 for (i = 0 ; i < sp->sa_len; i++) {
465 r[i] = p[i] & q[i];
466 /* XXX estimate */
467 matchlen += (q[i] ? 8 : 0);
468 }
469
470 p = (const u_int8_t *)dp;
471 q = (const u_int8_t *)&ep->dstmask;
472 r = (u_int8_t *)&d;
473 for (i = 0 ; i < dp->sa_len; i++) {
474 r[i] = p[i] & q[i];
475 /* XXX rough estimate */
476 matchlen += (q[i] ? 8 : 0);
477 }
478
479 /* need to overwrite len/family portion as we don't compare them */
480 s.ss_len = sp->sa_len;
481 s.ss_family = sp->sa_family;
482 d.ss_len = dp->sa_len;
483 d.ss_family = dp->sa_family;
484
485 if (bcmp(&s, &ep->src, ep->src.ss_len) == 0 &&
486 bcmp(&d, &ep->dst, ep->dst.ss_len) == 0) {
487 return matchlen;
488 } else
489 return 0;
490}
491
492static void
493encap_fillarg(m, ep)
494 struct mbuf *m;
495 const struct encaptab *ep;
496{
497 struct m_tag *tag;
498
74f1caca 499 tag = m_tag_get(PACKET_TAG_ENCAP, sizeof (void*), MB_DONTWAIT);
984263bc
MD
500 if (tag) {
501 *(void**)(tag+1) = ep->arg;
502 m_tag_prepend(m, tag);
503 }
504}
505
506void *
507encap_getarg(m)
508 struct mbuf *m;
509{
510 void *p = NULL;
511 struct m_tag *tag;
512
513 tag = m_tag_find(m, PACKET_TAG_ENCAP, NULL);
514 if (tag) {
515 p = *(void**)(tag+1);
516 m_tag_delete(m, tag);
517 }
518 return p;
519}