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[PARISC] Add NOTES section
[linux-2.6/mini2440.git] / net / ipv6 / mip6.c
blob8a1399ce38ce826ae774a54508382adae905603f
1 /*
2 * Copyright (C)2003-2006 Helsinki University of Technology
3 * Copyright (C)2003-2006 USAGI/WIDE Project
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19 /*
20 * Authors:
21 * Noriaki TAKAMIYA @USAGI
22 * Masahide NAKAMURA @USAGI
23 */
24
25 #include <linux/module.h>
26 #include <linux/skbuff.h>
27 #include <linux/time.h>
28 #include <linux/ipv6.h>
29 #include <linux/icmpv6.h>
30 #include <net/sock.h>
31 #include <net/ipv6.h>
32 #include <net/ip6_checksum.h>
33 #include <net/rawv6.h>
34 #include <net/xfrm.h>
35 #include <net/mip6.h>
36
37 static xfrm_address_t *mip6_xfrm_addr(struct xfrm_state *x, xfrm_address_t *addr)
38 {
39 return x->coaddr;
40 }
41
42 static inline unsigned int calc_padlen(unsigned int len, unsigned int n)
43 {
44 return (n - len + 16) & 0x7;
45 }
46
47 static inline void *mip6_padn(__u8 *data, __u8 padlen)
48 {
49 if (!data)
50 return NULL;
51 if (padlen == 1) {
52 data[0] = MIP6_OPT_PAD_1;
53 } else if (padlen > 1) {
54 data[0] = MIP6_OPT_PAD_N;
55 data[1] = padlen - 2;
56 if (padlen > 2)
57 memset(data+2, 0, data[1]);
58 }
59 return data + padlen;
60 }
61
62 static inline void mip6_param_prob(struct sk_buff *skb, int code, int pos)
63 {
64 icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos, skb->dev);
65 }
66
67 static int mip6_mh_len(int type)
68 {
69 int len = 0;
70
71 switch (type) {
72 case IP6_MH_TYPE_BRR:
73 len = 0;
74 break;
75 case IP6_MH_TYPE_HOTI:
76 case IP6_MH_TYPE_COTI:
77 case IP6_MH_TYPE_BU:
78 case IP6_MH_TYPE_BACK:
79 len = 1;
80 break;
81 case IP6_MH_TYPE_HOT:
82 case IP6_MH_TYPE_COT:
83 case IP6_MH_TYPE_BERROR:
84 len = 2;
85 break;
86 }
87 return len;
88 }
89
90 static int mip6_mh_filter(struct sock *sk, struct sk_buff *skb)
91 {
92 struct ip6_mh *mh;
93
94 if (!pskb_may_pull(skb, (skb_transport_offset(skb)) + 8) ||
95 !pskb_may_pull(skb, (skb_transport_offset(skb) +
96 ((skb_transport_header(skb)[1] + 1) << 3))))
97 return -1;
98
99 mh = (struct ip6_mh *)skb_transport_header(skb);
100
101 if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) {
102 LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH message too short: %d vs >=%d\n",
103 mh->ip6mh_hdrlen, mip6_mh_len(mh->ip6mh_type));
104 mip6_param_prob(skb, 0, ((&mh->ip6mh_hdrlen) -
105 skb_network_header(skb)));
106 return -1;
107 }
108
109 if (mh->ip6mh_proto != IPPROTO_NONE) {
110 LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH invalid payload proto = %d\n",
111 mh->ip6mh_proto);
112 mip6_param_prob(skb, 0, ((&mh->ip6mh_proto) -
113 skb_network_header(skb)));
114 return -1;
115 }
116
117 return 0;
118 }
119
120 struct mip6_report_rate_limiter {
121 spinlock_t lock;
122 struct timeval stamp;
123 int iif;
124 struct in6_addr src;
125 struct in6_addr dst;
126 };
127
128 static struct mip6_report_rate_limiter mip6_report_rl = {
129 .lock = __SPIN_LOCK_UNLOCKED(mip6_report_rl.lock)
130 };
131
132 static int mip6_destopt_input(struct xfrm_state *x, struct sk_buff *skb)
133 {
134 struct ipv6hdr *iph = ipv6_hdr(skb);
135 struct ipv6_destopt_hdr *destopt = (struct ipv6_destopt_hdr *)skb->data;
136
137 if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) &&
138 !ipv6_addr_any((struct in6_addr *)x->coaddr))
139 return -ENOENT;
140
141 return destopt->nexthdr;
142 }
143
144 /* Destination Option Header is inserted.
145 * IP Header's src address is replaced with Home Address Option in
146 * Destination Option Header.
147 */
148 static int mip6_destopt_output(struct xfrm_state *x, struct sk_buff *skb)
149 {
150 struct ipv6hdr *iph;
151 struct ipv6_destopt_hdr *dstopt;
152 struct ipv6_destopt_hao *hao;
153 u8 nexthdr;
154 int len;
155
156 iph = (struct ipv6hdr *)skb->data;
157 iph->payload_len = htons(skb->len - sizeof(*iph));
158
159 nexthdr = *skb_network_header(skb);
160 *skb_network_header(skb) = IPPROTO_DSTOPTS;
161
162 dstopt = (struct ipv6_destopt_hdr *)skb_transport_header(skb);
163 dstopt->nexthdr = nexthdr;
164
165 hao = mip6_padn((char *)(dstopt + 1),
166 calc_padlen(sizeof(*dstopt), 6));
167
168 hao->type = IPV6_TLV_HAO;
169 hao->length = sizeof(*hao) - 2;
170 BUG_TRAP(hao->length == 16);
171
172 len = ((char *)hao - (char *)dstopt) + sizeof(*hao);
173
174 memcpy(&hao->addr, &iph->saddr, sizeof(hao->addr));
175 memcpy(&iph->saddr, x->coaddr, sizeof(iph->saddr));
176
177 BUG_TRAP(len == x->props.header_len);
178 dstopt->hdrlen = (x->props.header_len >> 3) - 1;
179
180 return 0;
181 }
182
183 static inline int mip6_report_rl_allow(struct timeval *stamp,
184 struct in6_addr *dst,
185 struct in6_addr *src, int iif)
186 {
187 int allow = 0;
188
189 spin_lock_bh(&mip6_report_rl.lock);
190 if (mip6_report_rl.stamp.tv_sec != stamp->tv_sec ||
191 mip6_report_rl.stamp.tv_usec != stamp->tv_usec ||
192 mip6_report_rl.iif != iif ||
193 !ipv6_addr_equal(&mip6_report_rl.src, src) ||
194 !ipv6_addr_equal(&mip6_report_rl.dst, dst)) {
195 mip6_report_rl.stamp.tv_sec = stamp->tv_sec;
196 mip6_report_rl.stamp.tv_usec = stamp->tv_usec;
197 mip6_report_rl.iif = iif;
198 ipv6_addr_copy(&mip6_report_rl.src, src);
199 ipv6_addr_copy(&mip6_report_rl.dst, dst);
200 allow = 1;
201 }
202 spin_unlock_bh(&mip6_report_rl.lock);
203 return allow;
204 }
205
206 static int mip6_destopt_reject(struct xfrm_state *x, struct sk_buff *skb, struct flowi *fl)
207 {
208 struct inet6_skb_parm *opt = (struct inet6_skb_parm *)skb->cb;
209 struct ipv6_destopt_hao *hao = NULL;
210 struct xfrm_selector sel;
211 int offset;
212 struct timeval stamp;
213 int err = 0;
214
215 if (unlikely(fl->proto == IPPROTO_MH &&
216 fl->fl_mh_type <= IP6_MH_TYPE_MAX))
217 goto out;
218
219 if (likely(opt->dsthao)) {
220 offset = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
221 if (likely(offset >= 0))
222 hao = (struct ipv6_destopt_hao *)
223 (skb_network_header(skb) + offset);
224 }
225
226 skb_get_timestamp(skb, &stamp);
227
228 if (!mip6_report_rl_allow(&stamp, &ipv6_hdr(skb)->daddr,
229 hao ? &hao->addr : &ipv6_hdr(skb)->saddr,
230 opt->iif))
231 goto out;
232
233 memset(&sel, 0, sizeof(sel));
234 memcpy(&sel.daddr, (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
235 sizeof(sel.daddr));
236 sel.prefixlen_d = 128;
237 memcpy(&sel.saddr, (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
238 sizeof(sel.saddr));
239 sel.prefixlen_s = 128;
240 sel.family = AF_INET6;
241 sel.proto = fl->proto;
242 sel.dport = xfrm_flowi_dport(fl);
243 if (sel.dport)
244 sel.dport_mask = htons(~0);
245 sel.sport = xfrm_flowi_sport(fl);
246 if (sel.sport)
247 sel.sport_mask = htons(~0);
248 sel.ifindex = fl->oif;
249
250 err = km_report(IPPROTO_DSTOPTS, &sel,
251 (hao ? (xfrm_address_t *)&hao->addr : NULL));
252
253 out:
254 return err;
255 }
256
257 static int mip6_destopt_offset(struct xfrm_state *x, struct sk_buff *skb,
258 u8 **nexthdr)
259 {
260 u16 offset = sizeof(struct ipv6hdr);
261 struct ipv6_opt_hdr *exthdr =
262 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
263 const unsigned char *nh = skb_network_header(skb);
264 unsigned int packet_len = skb->tail - skb->network_header;
265 int found_rhdr = 0;
266
267 *nexthdr = &ipv6_hdr(skb)->nexthdr;
268
269 while (offset + 1 <= packet_len) {
270
271 switch (**nexthdr) {
272 case NEXTHDR_HOP:
273 break;
274 case NEXTHDR_ROUTING:
275 found_rhdr = 1;
276 break;
277 case NEXTHDR_DEST:
278 /*
279 * HAO MUST NOT appear more than once.
280 * XXX: It is better to try to find by the end of
281 * XXX: packet if HAO exists.
282 */
283 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) {
284 LIMIT_NETDEBUG(KERN_WARNING "mip6: hao exists already, override\n");
285 return offset;
286 }
287
288 if (found_rhdr)
289 return offset;
290
291 break;
292 default:
293 return offset;
294 }
295
296 offset += ipv6_optlen(exthdr);
297 *nexthdr = &exthdr->nexthdr;
298 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
299 }
300
301 return offset;
302 }
303
304 static int mip6_destopt_init_state(struct xfrm_state *x)
305 {
306 if (x->id.spi) {
307 printk(KERN_INFO "%s: spi is not 0: %u\n", __FUNCTION__,
308 x->id.spi);
309 return -EINVAL;
310 }
311 if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
312 printk(KERN_INFO "%s: state's mode is not %u: %u\n",
313 __FUNCTION__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
314 return -EINVAL;
315 }
316
317 x->props.header_len = sizeof(struct ipv6_destopt_hdr) +
318 calc_padlen(sizeof(struct ipv6_destopt_hdr), 6) +
319 sizeof(struct ipv6_destopt_hao);
320 BUG_TRAP(x->props.header_len == 24);
321
322 return 0;
323 }
324
325 /*
326 * Do nothing about destroying since it has no specific operation for
327 * destination options header unlike IPsec protocols.
328 */
329 static void mip6_destopt_destroy(struct xfrm_state *x)
330 {
331 }
332
333 static struct xfrm_type mip6_destopt_type =
334 {
335 .description = "MIP6DESTOPT",
336 .owner = THIS_MODULE,
337 .proto = IPPROTO_DSTOPTS,
338 .flags = XFRM_TYPE_NON_FRAGMENT,
339 .init_state = mip6_destopt_init_state,
340 .destructor = mip6_destopt_destroy,
341 .input = mip6_destopt_input,
342 .output = mip6_destopt_output,
343 .reject = mip6_destopt_reject,
344 .hdr_offset = mip6_destopt_offset,
345 .local_addr = mip6_xfrm_addr,
346 };
347
348 static int mip6_rthdr_input(struct xfrm_state *x, struct sk_buff *skb)
349 {
350 struct rt2_hdr *rt2 = (struct rt2_hdr *)skb->data;
351
352 if (!ipv6_addr_equal(&rt2->addr, (struct in6_addr *)x->coaddr) &&
353 !ipv6_addr_any((struct in6_addr *)x->coaddr))
354 return -ENOENT;
355
356 return rt2->rt_hdr.nexthdr;
357 }
358
359 /* Routing Header type 2 is inserted.
360 * IP Header's dst address is replaced with Routing Header's Home Address.
361 */
362 static int mip6_rthdr_output(struct xfrm_state *x, struct sk_buff *skb)
363 {
364 struct ipv6hdr *iph;
365 struct rt2_hdr *rt2;
366 u8 nexthdr;
367
368 iph = (struct ipv6hdr *)skb->data;
369 iph->payload_len = htons(skb->len - sizeof(*iph));
370
371 nexthdr = *skb_network_header(skb);
372 *skb_network_header(skb) = IPPROTO_ROUTING;
373
374 rt2 = (struct rt2_hdr *)skb_transport_header(skb);
375 rt2->rt_hdr.nexthdr = nexthdr;
376 rt2->rt_hdr.hdrlen = (x->props.header_len >> 3) - 1;
377 rt2->rt_hdr.type = IPV6_SRCRT_TYPE_2;
378 rt2->rt_hdr.segments_left = 1;
379 memset(&rt2->reserved, 0, sizeof(rt2->reserved));
380
381 BUG_TRAP(rt2->rt_hdr.hdrlen == 2);
382
383 memcpy(&rt2->addr, &iph->daddr, sizeof(rt2->addr));
384 memcpy(&iph->daddr, x->coaddr, sizeof(iph->daddr));
385
386 return 0;
387 }
388
389 static int mip6_rthdr_offset(struct xfrm_state *x, struct sk_buff *skb,
390 u8 **nexthdr)
391 {
392 u16 offset = sizeof(struct ipv6hdr);
393 struct ipv6_opt_hdr *exthdr =
394 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
395 const unsigned char *nh = skb_network_header(skb);
396 unsigned int packet_len = skb->tail - skb->network_header;
397 int found_rhdr = 0;
398
399 *nexthdr = &ipv6_hdr(skb)->nexthdr;
400
401 while (offset + 1 <= packet_len) {
402
403 switch (**nexthdr) {
404 case NEXTHDR_HOP:
405 break;
406 case NEXTHDR_ROUTING:
407 if (offset + 3 <= packet_len) {
408 struct ipv6_rt_hdr *rt;
409 rt = (struct ipv6_rt_hdr *)(nh + offset);
410 if (rt->type != 0)
411 return offset;
412 }
413 found_rhdr = 1;
414 break;
415 case NEXTHDR_DEST:
416 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
417 return offset;
418
419 if (found_rhdr)
420 return offset;
421
422 break;
423 default:
424 return offset;
425 }
426
427 offset += ipv6_optlen(exthdr);
428 *nexthdr = &exthdr->nexthdr;
429 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
430 }
431
432 return offset;
433 }
434
435 static int mip6_rthdr_init_state(struct xfrm_state *x)
436 {
437 if (x->id.spi) {
438 printk(KERN_INFO "%s: spi is not 0: %u\n", __FUNCTION__,
439 x->id.spi);
440 return -EINVAL;
441 }
442 if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
443 printk(KERN_INFO "%s: state's mode is not %u: %u\n",
444 __FUNCTION__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
445 return -EINVAL;
446 }
447
448 x->props.header_len = sizeof(struct rt2_hdr);
449
450 return 0;
451 }
452
453 /*
454 * Do nothing about destroying since it has no specific operation for routing
455 * header type 2 unlike IPsec protocols.
456 */
457 static void mip6_rthdr_destroy(struct xfrm_state *x)
458 {
459 }
460
461 static struct xfrm_type mip6_rthdr_type =
462 {
463 .description = "MIP6RT",
464 .owner = THIS_MODULE,
465 .proto = IPPROTO_ROUTING,
466 .flags = XFRM_TYPE_NON_FRAGMENT,
467 .init_state = mip6_rthdr_init_state,
468 .destructor = mip6_rthdr_destroy,
469 .input = mip6_rthdr_input,
470 .output = mip6_rthdr_output,
471 .hdr_offset = mip6_rthdr_offset,
472 .remote_addr = mip6_xfrm_addr,
473 };
474
475 static int __init mip6_init(void)
476 {
477 printk(KERN_INFO "Mobile IPv6\n");
478
479 if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) {
480 printk(KERN_INFO "%s: can't add xfrm type(destopt)\n", __FUNCTION__);
481 goto mip6_destopt_xfrm_fail;
482 }
483 if (xfrm_register_type(&mip6_rthdr_type, AF_INET6) < 0) {
484 printk(KERN_INFO "%s: can't add xfrm type(rthdr)\n", __FUNCTION__);
485 goto mip6_rthdr_xfrm_fail;
486 }
487 if (rawv6_mh_filter_register(mip6_mh_filter) < 0) {
488 printk(KERN_INFO "%s: can't add rawv6 mh filter\n", __FUNCTION__);
489 goto mip6_rawv6_mh_fail;
490 }
491
492
493 return 0;
494
495 mip6_rawv6_mh_fail:
496 xfrm_unregister_type(&mip6_rthdr_type, AF_INET6);
497 mip6_rthdr_xfrm_fail:
498 xfrm_unregister_type(&mip6_destopt_type, AF_INET6);
499 mip6_destopt_xfrm_fail:
500 return -EAGAIN;
501 }
502
503 static void __exit mip6_fini(void)
504 {
505 if (rawv6_mh_filter_unregister(mip6_mh_filter) < 0)
506 printk(KERN_INFO "%s: can't remove rawv6 mh filter\n", __FUNCTION__);
507 if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0)
508 printk(KERN_INFO "%s: can't remove xfrm type(rthdr)\n", __FUNCTION__);
509 if (xfrm_unregister_type(&mip6_destopt_type, AF_INET6) < 0)
510 printk(KERN_INFO "%s: can't remove xfrm type(destopt)\n", __FUNCTION__);
511 }
512
513 module_init(mip6_init);
514 module_exit(mip6_fini);
515
516 MODULE_LICENSE("GPL");
517 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_DSTOPTS);
518 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ROUTING);
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