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JFS is missing a memory barrier
[linux-2.6/mini2440.git] / net / ipv6 / mip6.c
blob7fd841d410190382fe5ea1c4b31df9ebada0f07f
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 skb_push(skb, -skb_network_offset(skb));
157 iph = ipv6_hdr(skb);
158
159 nexthdr = *skb_mac_header(skb);
160 *skb_mac_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 spin_lock_bh(&x->lock);
176 memcpy(&iph->saddr, x->coaddr, sizeof(iph->saddr));
177 spin_unlock_bh(&x->lock);
178
179 BUG_TRAP(len == x->props.header_len);
180 dstopt->hdrlen = (x->props.header_len >> 3) - 1;
181
182 return 0;
183 }
184
185 static inline int mip6_report_rl_allow(struct timeval *stamp,
186 struct in6_addr *dst,
187 struct in6_addr *src, int iif)
188 {
189 int allow = 0;
190
191 spin_lock_bh(&mip6_report_rl.lock);
192 if (mip6_report_rl.stamp.tv_sec != stamp->tv_sec ||
193 mip6_report_rl.stamp.tv_usec != stamp->tv_usec ||
194 mip6_report_rl.iif != iif ||
195 !ipv6_addr_equal(&mip6_report_rl.src, src) ||
196 !ipv6_addr_equal(&mip6_report_rl.dst, dst)) {
197 mip6_report_rl.stamp.tv_sec = stamp->tv_sec;
198 mip6_report_rl.stamp.tv_usec = stamp->tv_usec;
199 mip6_report_rl.iif = iif;
200 ipv6_addr_copy(&mip6_report_rl.src, src);
201 ipv6_addr_copy(&mip6_report_rl.dst, dst);
202 allow = 1;
203 }
204 spin_unlock_bh(&mip6_report_rl.lock);
205 return allow;
206 }
207
208 static int mip6_destopt_reject(struct xfrm_state *x, struct sk_buff *skb, struct flowi *fl)
209 {
210 struct inet6_skb_parm *opt = (struct inet6_skb_parm *)skb->cb;
211 struct ipv6_destopt_hao *hao = NULL;
212 struct xfrm_selector sel;
213 int offset;
214 struct timeval stamp;
215 int err = 0;
216
217 if (unlikely(fl->proto == IPPROTO_MH &&
218 fl->fl_mh_type <= IP6_MH_TYPE_MAX))
219 goto out;
220
221 if (likely(opt->dsthao)) {
222 offset = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
223 if (likely(offset >= 0))
224 hao = (struct ipv6_destopt_hao *)
225 (skb_network_header(skb) + offset);
226 }
227
228 skb_get_timestamp(skb, &stamp);
229
230 if (!mip6_report_rl_allow(&stamp, &ipv6_hdr(skb)->daddr,
231 hao ? &hao->addr : &ipv6_hdr(skb)->saddr,
232 opt->iif))
233 goto out;
234
235 memset(&sel, 0, sizeof(sel));
236 memcpy(&sel.daddr, (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
237 sizeof(sel.daddr));
238 sel.prefixlen_d = 128;
239 memcpy(&sel.saddr, (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
240 sizeof(sel.saddr));
241 sel.prefixlen_s = 128;
242 sel.family = AF_INET6;
243 sel.proto = fl->proto;
244 sel.dport = xfrm_flowi_dport(fl);
245 if (sel.dport)
246 sel.dport_mask = htons(~0);
247 sel.sport = xfrm_flowi_sport(fl);
248 if (sel.sport)
249 sel.sport_mask = htons(~0);
250 sel.ifindex = fl->oif;
251
252 err = km_report(IPPROTO_DSTOPTS, &sel,
253 (hao ? (xfrm_address_t *)&hao->addr : NULL));
254
255 out:
256 return err;
257 }
258
259 static int mip6_destopt_offset(struct xfrm_state *x, struct sk_buff *skb,
260 u8 **nexthdr)
261 {
262 u16 offset = sizeof(struct ipv6hdr);
263 struct ipv6_opt_hdr *exthdr =
264 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
265 const unsigned char *nh = skb_network_header(skb);
266 unsigned int packet_len = skb->tail - skb->network_header;
267 int found_rhdr = 0;
268
269 *nexthdr = &ipv6_hdr(skb)->nexthdr;
270
271 while (offset + 1 <= packet_len) {
272
273 switch (**nexthdr) {
274 case NEXTHDR_HOP:
275 break;
276 case NEXTHDR_ROUTING:
277 found_rhdr = 1;
278 break;
279 case NEXTHDR_DEST:
280 /*
281 * HAO MUST NOT appear more than once.
282 * XXX: It is better to try to find by the end of
283 * XXX: packet if HAO exists.
284 */
285 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) {
286 LIMIT_NETDEBUG(KERN_WARNING "mip6: hao exists already, override\n");
287 return offset;
288 }
289
290 if (found_rhdr)
291 return offset;
292
293 break;
294 default:
295 return offset;
296 }
297
298 offset += ipv6_optlen(exthdr);
299 *nexthdr = &exthdr->nexthdr;
300 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
301 }
302
303 return offset;
304 }
305
306 static int mip6_destopt_init_state(struct xfrm_state *x)
307 {
308 if (x->id.spi) {
309 printk(KERN_INFO "%s: spi is not 0: %u\n", __FUNCTION__,
310 x->id.spi);
311 return -EINVAL;
312 }
313 if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
314 printk(KERN_INFO "%s: state's mode is not %u: %u\n",
315 __FUNCTION__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
316 return -EINVAL;
317 }
318
319 x->props.header_len = sizeof(struct ipv6_destopt_hdr) +
320 calc_padlen(sizeof(struct ipv6_destopt_hdr), 6) +
321 sizeof(struct ipv6_destopt_hao);
322 BUG_TRAP(x->props.header_len == 24);
323
324 return 0;
325 }
326
327 /*
328 * Do nothing about destroying since it has no specific operation for
329 * destination options header unlike IPsec protocols.
330 */
331 static void mip6_destopt_destroy(struct xfrm_state *x)
332 {
333 }
334
335 static struct xfrm_type mip6_destopt_type =
336 {
337 .description = "MIP6DESTOPT",
338 .owner = THIS_MODULE,
339 .proto = IPPROTO_DSTOPTS,
340 .flags = XFRM_TYPE_NON_FRAGMENT,
341 .init_state = mip6_destopt_init_state,
342 .destructor = mip6_destopt_destroy,
343 .input = mip6_destopt_input,
344 .output = mip6_destopt_output,
345 .reject = mip6_destopt_reject,
346 .hdr_offset = mip6_destopt_offset,
347 .local_addr = mip6_xfrm_addr,
348 };
349
350 static int mip6_rthdr_input(struct xfrm_state *x, struct sk_buff *skb)
351 {
352 struct rt2_hdr *rt2 = (struct rt2_hdr *)skb->data;
353
354 if (!ipv6_addr_equal(&rt2->addr, (struct in6_addr *)x->coaddr) &&
355 !ipv6_addr_any((struct in6_addr *)x->coaddr))
356 return -ENOENT;
357
358 return rt2->rt_hdr.nexthdr;
359 }
360
361 /* Routing Header type 2 is inserted.
362 * IP Header's dst address is replaced with Routing Header's Home Address.
363 */
364 static int mip6_rthdr_output(struct xfrm_state *x, struct sk_buff *skb)
365 {
366 struct ipv6hdr *iph;
367 struct rt2_hdr *rt2;
368 u8 nexthdr;
369
370 skb_push(skb, -skb_network_offset(skb));
371 iph = ipv6_hdr(skb);
372
373 nexthdr = *skb_mac_header(skb);
374 *skb_mac_header(skb) = IPPROTO_ROUTING;
375
376 rt2 = (struct rt2_hdr *)skb_transport_header(skb);
377 rt2->rt_hdr.nexthdr = nexthdr;
378 rt2->rt_hdr.hdrlen = (x->props.header_len >> 3) - 1;
379 rt2->rt_hdr.type = IPV6_SRCRT_TYPE_2;
380 rt2->rt_hdr.segments_left = 1;
381 memset(&rt2->reserved, 0, sizeof(rt2->reserved));
382
383 BUG_TRAP(rt2->rt_hdr.hdrlen == 2);
384
385 memcpy(&rt2->addr, &iph->daddr, sizeof(rt2->addr));
386 spin_lock_bh(&x->lock);
387 memcpy(&iph->daddr, x->coaddr, sizeof(iph->daddr));
388 spin_unlock_bh(&x->lock);
389
390 return 0;
391 }
392
393 static int mip6_rthdr_offset(struct xfrm_state *x, struct sk_buff *skb,
394 u8 **nexthdr)
395 {
396 u16 offset = sizeof(struct ipv6hdr);
397 struct ipv6_opt_hdr *exthdr =
398 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
399 const unsigned char *nh = skb_network_header(skb);
400 unsigned int packet_len = skb->tail - skb->network_header;
401 int found_rhdr = 0;
402
403 *nexthdr = &ipv6_hdr(skb)->nexthdr;
404
405 while (offset + 1 <= packet_len) {
406
407 switch (**nexthdr) {
408 case NEXTHDR_HOP:
409 break;
410 case NEXTHDR_ROUTING:
411 if (offset + 3 <= packet_len) {
412 struct ipv6_rt_hdr *rt;
413 rt = (struct ipv6_rt_hdr *)(nh + offset);
414 if (rt->type != 0)
415 return offset;
416 }
417 found_rhdr = 1;
418 break;
419 case NEXTHDR_DEST:
420 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
421 return offset;
422
423 if (found_rhdr)
424 return offset;
425
426 break;
427 default:
428 return offset;
429 }
430
431 offset += ipv6_optlen(exthdr);
432 *nexthdr = &exthdr->nexthdr;
433 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
434 }
435
436 return offset;
437 }
438
439 static int mip6_rthdr_init_state(struct xfrm_state *x)
440 {
441 if (x->id.spi) {
442 printk(KERN_INFO "%s: spi is not 0: %u\n", __FUNCTION__,
443 x->id.spi);
444 return -EINVAL;
445 }
446 if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
447 printk(KERN_INFO "%s: state's mode is not %u: %u\n",
448 __FUNCTION__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
449 return -EINVAL;
450 }
451
452 x->props.header_len = sizeof(struct rt2_hdr);
453
454 return 0;
455 }
456
457 /*
458 * Do nothing about destroying since it has no specific operation for routing
459 * header type 2 unlike IPsec protocols.
460 */
461 static void mip6_rthdr_destroy(struct xfrm_state *x)
462 {
463 }
464
465 static struct xfrm_type mip6_rthdr_type =
466 {
467 .description = "MIP6RT",
468 .owner = THIS_MODULE,
469 .proto = IPPROTO_ROUTING,
470 .flags = XFRM_TYPE_NON_FRAGMENT,
471 .init_state = mip6_rthdr_init_state,
472 .destructor = mip6_rthdr_destroy,
473 .input = mip6_rthdr_input,
474 .output = mip6_rthdr_output,
475 .hdr_offset = mip6_rthdr_offset,
476 .remote_addr = mip6_xfrm_addr,
477 };
478
479 static int __init mip6_init(void)
480 {
481 printk(KERN_INFO "Mobile IPv6\n");
482
483 if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) {
484 printk(KERN_INFO "%s: can't add xfrm type(destopt)\n", __FUNCTION__);
485 goto mip6_destopt_xfrm_fail;
486 }
487 if (xfrm_register_type(&mip6_rthdr_type, AF_INET6) < 0) {
488 printk(KERN_INFO "%s: can't add xfrm type(rthdr)\n", __FUNCTION__);
489 goto mip6_rthdr_xfrm_fail;
490 }
491 if (rawv6_mh_filter_register(mip6_mh_filter) < 0) {
492 printk(KERN_INFO "%s: can't add rawv6 mh filter\n", __FUNCTION__);
493 goto mip6_rawv6_mh_fail;
494 }
495
496
497 return 0;
498
499 mip6_rawv6_mh_fail:
500 xfrm_unregister_type(&mip6_rthdr_type, AF_INET6);
501 mip6_rthdr_xfrm_fail:
502 xfrm_unregister_type(&mip6_destopt_type, AF_INET6);
503 mip6_destopt_xfrm_fail:
504 return -EAGAIN;
505 }
506
507 static void __exit mip6_fini(void)
508 {
509 if (rawv6_mh_filter_unregister(mip6_mh_filter) < 0)
510 printk(KERN_INFO "%s: can't remove rawv6 mh filter\n", __FUNCTION__);
511 if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0)
512 printk(KERN_INFO "%s: can't remove xfrm type(rthdr)\n", __FUNCTION__);
513 if (xfrm_unregister_type(&mip6_destopt_type, AF_INET6) < 0)
514 printk(KERN_INFO "%s: can't remove xfrm type(destopt)\n", __FUNCTION__);
515 }
516
517 module_init(mip6_init);
518 module_exit(mip6_fini);
519
520 MODULE_LICENSE("GPL");
521 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_DSTOPTS);
522 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ROUTING);
Support for the Chinese Samsung S3C2440 based development boards