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USB: core: remove unused dbg() call in message.c
[linux-2.6/btrfs-unstable.git] / net / ipv6 / mip6.c
blob5b087c31d87b54f5a2574903775b81692bcd2616
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
26
27 #include <linux/module.h>
28 #include <linux/skbuff.h>
29 #include <linux/time.h>
30 #include <linux/ipv6.h>
31 #include <linux/icmpv6.h>
32 #include <net/sock.h>
33 #include <net/ipv6.h>
34 #include <net/ip6_checksum.h>
35 #include <net/rawv6.h>
36 #include <net/xfrm.h>
37 #include <net/mip6.h>
38
39 static inline unsigned int calc_padlen(unsigned int len, unsigned int n)
40 {
41 return (n - len + 16) & 0x7;
42 }
43
44 static inline void *mip6_padn(__u8 *data, __u8 padlen)
45 {
46 if (!data)
47 return NULL;
48 if (padlen == 1) {
49 data[0] = IPV6_TLV_PAD1;
50 } else if (padlen > 1) {
51 data[0] = IPV6_TLV_PADN;
52 data[1] = padlen - 2;
53 if (padlen > 2)
54 memset(data+2, 0, data[1]);
55 }
56 return data + padlen;
57 }
58
59 static inline void mip6_param_prob(struct sk_buff *skb, u8 code, int pos)
60 {
61 icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos);
62 }
63
64 static int mip6_mh_len(int type)
65 {
66 int len = 0;
67
68 switch (type) {
69 case IP6_MH_TYPE_BRR:
70 len = 0;
71 break;
72 case IP6_MH_TYPE_HOTI:
73 case IP6_MH_TYPE_COTI:
74 case IP6_MH_TYPE_BU:
75 case IP6_MH_TYPE_BACK:
76 len = 1;
77 break;
78 case IP6_MH_TYPE_HOT:
79 case IP6_MH_TYPE_COT:
80 case IP6_MH_TYPE_BERROR:
81 len = 2;
82 break;
83 }
84 return len;
85 }
86
87 static int mip6_mh_filter(struct sock *sk, struct sk_buff *skb)
88 {
89 struct ip6_mh *mh;
90
91 if (!pskb_may_pull(skb, (skb_transport_offset(skb)) + 8) ||
92 !pskb_may_pull(skb, (skb_transport_offset(skb) +
93 ((skb_transport_header(skb)[1] + 1) << 3))))
94 return -1;
95
96 mh = (struct ip6_mh *)skb_transport_header(skb);
97
98 if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) {
99 LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH message too short: %d vs >=%d\n",
100 mh->ip6mh_hdrlen, mip6_mh_len(mh->ip6mh_type));
101 mip6_param_prob(skb, 0, ((&mh->ip6mh_hdrlen) -
102 skb_network_header(skb)));
103 return -1;
104 }
105
106 if (mh->ip6mh_proto != IPPROTO_NONE) {
107 LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH invalid payload proto = %d\n",
108 mh->ip6mh_proto);
109 mip6_param_prob(skb, 0, ((&mh->ip6mh_proto) -
110 skb_network_header(skb)));
111 return -1;
112 }
113
114 return 0;
115 }
116
117 struct mip6_report_rate_limiter {
118 spinlock_t lock;
119 struct timeval stamp;
120 int iif;
121 struct in6_addr src;
122 struct in6_addr dst;
123 };
124
125 static struct mip6_report_rate_limiter mip6_report_rl = {
126 .lock = __SPIN_LOCK_UNLOCKED(mip6_report_rl.lock)
127 };
128
129 static int mip6_destopt_input(struct xfrm_state *x, struct sk_buff *skb)
130 {
131 const struct ipv6hdr *iph = ipv6_hdr(skb);
132 struct ipv6_destopt_hdr *destopt = (struct ipv6_destopt_hdr *)skb->data;
133 int err = destopt->nexthdr;
134
135 spin_lock(&x->lock);
136 if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) &&
137 !ipv6_addr_any((struct in6_addr *)x->coaddr))
138 err = -ENOENT;
139 spin_unlock(&x->lock);
140
141 return err;
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 BUILD_BUG_ON(sizeof(*hao) != 18);
170 hao->length = sizeof(*hao) - 2;
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 WARN_ON(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 const struct in6_addr *dst,
187 const 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 mip6_report_rl.src = *src;
201 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,
209 const struct flowi *fl)
210 {
211 struct net *net = xs_net(x);
212 struct inet6_skb_parm *opt = (struct inet6_skb_parm *)skb->cb;
213 const struct flowi6 *fl6 = &fl->u.ip6;
214 struct ipv6_destopt_hao *hao = NULL;
215 struct xfrm_selector sel;
216 int offset;
217 struct timeval stamp;
218 int err = 0;
219
220 if (unlikely(fl6->flowi6_proto == IPPROTO_MH &&
221 fl6->fl6_mh_type <= IP6_MH_TYPE_MAX))
222 goto out;
223
224 if (likely(opt->dsthao)) {
225 offset = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
226 if (likely(offset >= 0))
227 hao = (struct ipv6_destopt_hao *)
228 (skb_network_header(skb) + offset);
229 }
230
231 skb_get_timestamp(skb, &stamp);
232
233 if (!mip6_report_rl_allow(&stamp, &ipv6_hdr(skb)->daddr,
234 hao ? &hao->addr : &ipv6_hdr(skb)->saddr,
235 opt->iif))
236 goto out;
237
238 memset(&sel, 0, sizeof(sel));
239 memcpy(&sel.daddr, (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
240 sizeof(sel.daddr));
241 sel.prefixlen_d = 128;
242 memcpy(&sel.saddr, (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
243 sizeof(sel.saddr));
244 sel.prefixlen_s = 128;
245 sel.family = AF_INET6;
246 sel.proto = fl6->flowi6_proto;
247 sel.dport = xfrm_flowi_dport(fl, &fl6->uli);
248 if (sel.dport)
249 sel.dport_mask = htons(~0);
250 sel.sport = xfrm_flowi_sport(fl, &fl6->uli);
251 if (sel.sport)
252 sel.sport_mask = htons(~0);
253 sel.ifindex = fl6->flowi6_oif;
254
255 err = km_report(net, IPPROTO_DSTOPTS, &sel,
256 (hao ? (xfrm_address_t *)&hao->addr : NULL));
257
258 out:
259 return err;
260 }
261
262 static int mip6_destopt_offset(struct xfrm_state *x, struct sk_buff *skb,
263 u8 **nexthdr)
264 {
265 u16 offset = sizeof(struct ipv6hdr);
266 struct ipv6_opt_hdr *exthdr =
267 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
268 const unsigned char *nh = skb_network_header(skb);
269 unsigned int packet_len = skb->tail - skb->network_header;
270 int found_rhdr = 0;
271
272 *nexthdr = &ipv6_hdr(skb)->nexthdr;
273
274 while (offset + 1 <= packet_len) {
275
276 switch (**nexthdr) {
277 case NEXTHDR_HOP:
278 break;
279 case NEXTHDR_ROUTING:
280 found_rhdr = 1;
281 break;
282 case NEXTHDR_DEST:
283 /*
284 * HAO MUST NOT appear more than once.
285 * XXX: It is better to try to find by the end of
286 * XXX: packet if HAO exists.
287 */
288 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) {
289 LIMIT_NETDEBUG(KERN_WARNING "mip6: hao exists already, override\n");
290 return offset;
291 }
292
293 if (found_rhdr)
294 return offset;
295
296 break;
297 default:
298 return offset;
299 }
300
301 offset += ipv6_optlen(exthdr);
302 *nexthdr = &exthdr->nexthdr;
303 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
304 }
305
306 return offset;
307 }
308
309 static int mip6_destopt_init_state(struct xfrm_state *x)
310 {
311 if (x->id.spi) {
312 pr_info("%s: spi is not 0: %u\n", __func__, x->id.spi);
313 return -EINVAL;
314 }
315 if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
316 pr_info("%s: state's mode is not %u: %u\n",
317 __func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
318 return -EINVAL;
319 }
320
321 x->props.header_len = sizeof(struct ipv6_destopt_hdr) +
322 calc_padlen(sizeof(struct ipv6_destopt_hdr), 6) +
323 sizeof(struct ipv6_destopt_hao);
324 WARN_ON(x->props.header_len != 24);
325
326 return 0;
327 }
328
329 /*
330 * Do nothing about destroying since it has no specific operation for
331 * destination options header unlike IPsec protocols.
332 */
333 static void mip6_destopt_destroy(struct xfrm_state *x)
334 {
335 }
336
337 static const struct xfrm_type mip6_destopt_type =
338 {
339 .description = "MIP6DESTOPT",
340 .owner = THIS_MODULE,
341 .proto = IPPROTO_DSTOPTS,
342 .flags = XFRM_TYPE_NON_FRAGMENT | XFRM_TYPE_LOCAL_COADDR,
343 .init_state = mip6_destopt_init_state,
344 .destructor = mip6_destopt_destroy,
345 .input = mip6_destopt_input,
346 .output = mip6_destopt_output,
347 .reject = mip6_destopt_reject,
348 .hdr_offset = mip6_destopt_offset,
349 };
350
351 static int mip6_rthdr_input(struct xfrm_state *x, struct sk_buff *skb)
352 {
353 const struct ipv6hdr *iph = ipv6_hdr(skb);
354 struct rt2_hdr *rt2 = (struct rt2_hdr *)skb->data;
355 int err = rt2->rt_hdr.nexthdr;
356
357 spin_lock(&x->lock);
358 if (!ipv6_addr_equal(&iph->daddr, (struct in6_addr *)x->coaddr) &&
359 !ipv6_addr_any((struct in6_addr *)x->coaddr))
360 err = -ENOENT;
361 spin_unlock(&x->lock);
362
363 return err;
364 }
365
366 /* Routing Header type 2 is inserted.
367 * IP Header's dst address is replaced with Routing Header's Home Address.
368 */
369 static int mip6_rthdr_output(struct xfrm_state *x, struct sk_buff *skb)
370 {
371 struct ipv6hdr *iph;
372 struct rt2_hdr *rt2;
373 u8 nexthdr;
374
375 skb_push(skb, -skb_network_offset(skb));
376 iph = ipv6_hdr(skb);
377
378 nexthdr = *skb_mac_header(skb);
379 *skb_mac_header(skb) = IPPROTO_ROUTING;
380
381 rt2 = (struct rt2_hdr *)skb_transport_header(skb);
382 rt2->rt_hdr.nexthdr = nexthdr;
383 rt2->rt_hdr.hdrlen = (x->props.header_len >> 3) - 1;
384 rt2->rt_hdr.type = IPV6_SRCRT_TYPE_2;
385 rt2->rt_hdr.segments_left = 1;
386 memset(&rt2->reserved, 0, sizeof(rt2->reserved));
387
388 WARN_ON(rt2->rt_hdr.hdrlen != 2);
389
390 memcpy(&rt2->addr, &iph->daddr, sizeof(rt2->addr));
391 spin_lock_bh(&x->lock);
392 memcpy(&iph->daddr, x->coaddr, sizeof(iph->daddr));
393 spin_unlock_bh(&x->lock);
394
395 return 0;
396 }
397
398 static int mip6_rthdr_offset(struct xfrm_state *x, struct sk_buff *skb,
399 u8 **nexthdr)
400 {
401 u16 offset = sizeof(struct ipv6hdr);
402 struct ipv6_opt_hdr *exthdr =
403 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
404 const unsigned char *nh = skb_network_header(skb);
405 unsigned int packet_len = skb->tail - skb->network_header;
406 int found_rhdr = 0;
407
408 *nexthdr = &ipv6_hdr(skb)->nexthdr;
409
410 while (offset + 1 <= packet_len) {
411
412 switch (**nexthdr) {
413 case NEXTHDR_HOP:
414 break;
415 case NEXTHDR_ROUTING:
416 if (offset + 3 <= packet_len) {
417 struct ipv6_rt_hdr *rt;
418 rt = (struct ipv6_rt_hdr *)(nh + offset);
419 if (rt->type != 0)
420 return offset;
421 }
422 found_rhdr = 1;
423 break;
424 case NEXTHDR_DEST:
425 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
426 return offset;
427
428 if (found_rhdr)
429 return offset;
430
431 break;
432 default:
433 return offset;
434 }
435
436 offset += ipv6_optlen(exthdr);
437 *nexthdr = &exthdr->nexthdr;
438 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
439 }
440
441 return offset;
442 }
443
444 static int mip6_rthdr_init_state(struct xfrm_state *x)
445 {
446 if (x->id.spi) {
447 pr_info("%s: spi is not 0: %u\n", __func__, x->id.spi);
448 return -EINVAL;
449 }
450 if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
451 pr_info("%s: state's mode is not %u: %u\n",
452 __func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
453 return -EINVAL;
454 }
455
456 x->props.header_len = sizeof(struct rt2_hdr);
457
458 return 0;
459 }
460
461 /*
462 * Do nothing about destroying since it has no specific operation for routing
463 * header type 2 unlike IPsec protocols.
464 */
465 static void mip6_rthdr_destroy(struct xfrm_state *x)
466 {
467 }
468
469 static const struct xfrm_type mip6_rthdr_type =
470 {
471 .description = "MIP6RT",
472 .owner = THIS_MODULE,
473 .proto = IPPROTO_ROUTING,
474 .flags = XFRM_TYPE_NON_FRAGMENT | XFRM_TYPE_REMOTE_COADDR,
475 .init_state = mip6_rthdr_init_state,
476 .destructor = mip6_rthdr_destroy,
477 .input = mip6_rthdr_input,
478 .output = mip6_rthdr_output,
479 .hdr_offset = mip6_rthdr_offset,
480 };
481
482 static int __init mip6_init(void)
483 {
484 pr_info("Mobile IPv6\n");
485
486 if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) {
487 pr_info("%s: can't add xfrm type(destopt)\n", __func__);
488 goto mip6_destopt_xfrm_fail;
489 }
490 if (xfrm_register_type(&mip6_rthdr_type, AF_INET6) < 0) {
491 pr_info("%s: can't add xfrm type(rthdr)\n", __func__);
492 goto mip6_rthdr_xfrm_fail;
493 }
494 if (rawv6_mh_filter_register(mip6_mh_filter) < 0) {
495 pr_info("%s: can't add rawv6 mh filter\n", __func__);
496 goto mip6_rawv6_mh_fail;
497 }
498
499
500 return 0;
501
502 mip6_rawv6_mh_fail:
503 xfrm_unregister_type(&mip6_rthdr_type, AF_INET6);
504 mip6_rthdr_xfrm_fail:
505 xfrm_unregister_type(&mip6_destopt_type, AF_INET6);
506 mip6_destopt_xfrm_fail:
507 return -EAGAIN;
508 }
509
510 static void __exit mip6_fini(void)
511 {
512 if (rawv6_mh_filter_unregister(mip6_mh_filter) < 0)
513 pr_info("%s: can't remove rawv6 mh filter\n", __func__);
514 if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0)
515 pr_info("%s: can't remove xfrm type(rthdr)\n", __func__);
516 if (xfrm_unregister_type(&mip6_destopt_type, AF_INET6) < 0)
517 pr_info("%s: can't remove xfrm type(destopt)\n", __func__);
518 }
519
520 module_init(mip6_init);
521 module_exit(mip6_fini);
522
523 MODULE_LICENSE("GPL");
524 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_DSTOPTS);
525 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ROUTING);
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