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workqueue: async worker destruction
[linux-2.6/btrfs-unstable.git] / net / ipv6 / mip6.c
blobdb9b6cbc9db3905695888343912be7dfd06af6f2
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, see <http://www.gnu.org/licenses/>.
17 */
18 /*
19 * Authors:
20 * Noriaki TAKAMIYA @USAGI
21 * Masahide NAKAMURA @USAGI
22 */
23
24 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
25
26 #include <linux/module.h>
27 #include <linux/skbuff.h>
28 #include <linux/time.h>
29 #include <linux/ipv6.h>
30 #include <linux/icmpv6.h>
31 #include <net/sock.h>
32 #include <net/ipv6.h>
33 #include <net/ip6_checksum.h>
34 #include <net/rawv6.h>
35 #include <net/xfrm.h>
36 #include <net/mip6.h>
37
38 static inline unsigned int calc_padlen(unsigned int len, unsigned int n)
39 {
40 return (n - len + 16) & 0x7;
41 }
42
43 static inline void *mip6_padn(__u8 *data, __u8 padlen)
44 {
45 if (!data)
46 return NULL;
47 if (padlen == 1) {
48 data[0] = IPV6_TLV_PAD1;
49 } else if (padlen > 1) {
50 data[0] = IPV6_TLV_PADN;
51 data[1] = padlen - 2;
52 if (padlen > 2)
53 memset(data+2, 0, data[1]);
54 }
55 return data + padlen;
56 }
57
58 static inline void mip6_param_prob(struct sk_buff *skb, u8 code, int pos)
59 {
60 icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos);
61 }
62
63 static int mip6_mh_len(int type)
64 {
65 int len = 0;
66
67 switch (type) {
68 case IP6_MH_TYPE_BRR:
69 len = 0;
70 break;
71 case IP6_MH_TYPE_HOTI:
72 case IP6_MH_TYPE_COTI:
73 case IP6_MH_TYPE_BU:
74 case IP6_MH_TYPE_BACK:
75 len = 1;
76 break;
77 case IP6_MH_TYPE_HOT:
78 case IP6_MH_TYPE_COT:
79 case IP6_MH_TYPE_BERROR:
80 len = 2;
81 break;
82 }
83 return len;
84 }
85
86 static int mip6_mh_filter(struct sock *sk, struct sk_buff *skb)
87 {
88 struct ip6_mh _hdr;
89 const struct ip6_mh *mh;
90
91 mh = skb_header_pointer(skb, skb_transport_offset(skb),
92 sizeof(_hdr), &_hdr);
93 if (!mh)
94 return -1;
95
96 if (((mh->ip6mh_hdrlen + 1) << 3) > skb->len)
97 return -1;
98
99 if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) {
100 LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH message too short: %d vs >=%d\n",
101 mh->ip6mh_hdrlen, mip6_mh_len(mh->ip6mh_type));
102 mip6_param_prob(skb, 0, offsetof(struct ip6_mh, ip6mh_hdrlen) +
103 skb_network_header_len(skb));
104 return -1;
105 }
106
107 if (mh->ip6mh_proto != IPPROTO_NONE) {
108 LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH invalid payload proto = %d\n",
109 mh->ip6mh_proto);
110 mip6_param_prob(skb, 0, offsetof(struct ip6_mh, ip6mh_proto) +
111 skb_network_header_len(skb));
112 return -1;
113 }
114
115 return 0;
116 }
117
118 struct mip6_report_rate_limiter {
119 spinlock_t lock;
120 struct timeval stamp;
121 int iif;
122 struct in6_addr src;
123 struct in6_addr dst;
124 };
125
126 static struct mip6_report_rate_limiter mip6_report_rl = {
127 .lock = __SPIN_LOCK_UNLOCKED(mip6_report_rl.lock)
128 };
129
130 static int mip6_destopt_input(struct xfrm_state *x, struct sk_buff *skb)
131 {
132 const struct ipv6hdr *iph = ipv6_hdr(skb);
133 struct ipv6_destopt_hdr *destopt = (struct ipv6_destopt_hdr *)skb->data;
134 int err = destopt->nexthdr;
135
136 spin_lock(&x->lock);
137 if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) &&
138 !ipv6_addr_any((struct in6_addr *)x->coaddr))
139 err = -ENOENT;
140 spin_unlock(&x->lock);
141
142 return err;
143 }
144
145 /* Destination Option Header is inserted.
146 * IP Header's src address is replaced with Home Address Option in
147 * Destination Option Header.
148 */
149 static int mip6_destopt_output(struct xfrm_state *x, struct sk_buff *skb)
150 {
151 struct ipv6hdr *iph;
152 struct ipv6_destopt_hdr *dstopt;
153 struct ipv6_destopt_hao *hao;
154 u8 nexthdr;
155 int len;
156
157 skb_push(skb, -skb_network_offset(skb));
158 iph = ipv6_hdr(skb);
159
160 nexthdr = *skb_mac_header(skb);
161 *skb_mac_header(skb) = IPPROTO_DSTOPTS;
162
163 dstopt = (struct ipv6_destopt_hdr *)skb_transport_header(skb);
164 dstopt->nexthdr = nexthdr;
165
166 hao = mip6_padn((char *)(dstopt + 1),
167 calc_padlen(sizeof(*dstopt), 6));
168
169 hao->type = IPV6_TLV_HAO;
170 BUILD_BUG_ON(sizeof(*hao) != 18);
171 hao->length = sizeof(*hao) - 2;
172
173 len = ((char *)hao - (char *)dstopt) + sizeof(*hao);
174
175 memcpy(&hao->addr, &iph->saddr, sizeof(hao->addr));
176 spin_lock_bh(&x->lock);
177 memcpy(&iph->saddr, x->coaddr, sizeof(iph->saddr));
178 spin_unlock_bh(&x->lock);
179
180 WARN_ON(len != x->props.header_len);
181 dstopt->hdrlen = (x->props.header_len >> 3) - 1;
182
183 return 0;
184 }
185
186 static inline int mip6_report_rl_allow(struct timeval *stamp,
187 const struct in6_addr *dst,
188 const struct in6_addr *src, int iif)
189 {
190 int allow = 0;
191
192 spin_lock_bh(&mip6_report_rl.lock);
193 if (mip6_report_rl.stamp.tv_sec != stamp->tv_sec ||
194 mip6_report_rl.stamp.tv_usec != stamp->tv_usec ||
195 mip6_report_rl.iif != iif ||
196 !ipv6_addr_equal(&mip6_report_rl.src, src) ||
197 !ipv6_addr_equal(&mip6_report_rl.dst, dst)) {
198 mip6_report_rl.stamp.tv_sec = stamp->tv_sec;
199 mip6_report_rl.stamp.tv_usec = stamp->tv_usec;
200 mip6_report_rl.iif = iif;
201 mip6_report_rl.src = *src;
202 mip6_report_rl.dst = *dst;
203 allow = 1;
204 }
205 spin_unlock_bh(&mip6_report_rl.lock);
206 return allow;
207 }
208
209 static int mip6_destopt_reject(struct xfrm_state *x, struct sk_buff *skb,
210 const struct flowi *fl)
211 {
212 struct net *net = xs_net(x);
213 struct inet6_skb_parm *opt = (struct inet6_skb_parm *)skb->cb;
214 const struct flowi6 *fl6 = &fl->u.ip6;
215 struct ipv6_destopt_hao *hao = NULL;
216 struct xfrm_selector sel;
217 int offset;
218 struct timeval stamp;
219 int err = 0;
220
221 if (unlikely(fl6->flowi6_proto == IPPROTO_MH &&
222 fl6->fl6_mh_type <= IP6_MH_TYPE_MAX))
223 goto out;
224
225 if (likely(opt->dsthao)) {
226 offset = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
227 if (likely(offset >= 0))
228 hao = (struct ipv6_destopt_hao *)
229 (skb_network_header(skb) + offset);
230 }
231
232 skb_get_timestamp(skb, &stamp);
233
234 if (!mip6_report_rl_allow(&stamp, &ipv6_hdr(skb)->daddr,
235 hao ? &hao->addr : &ipv6_hdr(skb)->saddr,
236 opt->iif))
237 goto out;
238
239 memset(&sel, 0, sizeof(sel));
240 memcpy(&sel.daddr, (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
241 sizeof(sel.daddr));
242 sel.prefixlen_d = 128;
243 memcpy(&sel.saddr, (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
244 sizeof(sel.saddr));
245 sel.prefixlen_s = 128;
246 sel.family = AF_INET6;
247 sel.proto = fl6->flowi6_proto;
248 sel.dport = xfrm_flowi_dport(fl, &fl6->uli);
249 if (sel.dport)
250 sel.dport_mask = htons(~0);
251 sel.sport = xfrm_flowi_sport(fl, &fl6->uli);
252 if (sel.sport)
253 sel.sport_mask = htons(~0);
254 sel.ifindex = fl6->flowi6_oif;
255
256 err = km_report(net, IPPROTO_DSTOPTS, &sel,
257 (hao ? (xfrm_address_t *)&hao->addr : NULL));
258
259 out:
260 return err;
261 }
262
263 static int mip6_destopt_offset(struct xfrm_state *x, struct sk_buff *skb,
264 u8 **nexthdr)
265 {
266 u16 offset = sizeof(struct ipv6hdr);
267 struct ipv6_opt_hdr *exthdr =
268 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
269 const unsigned char *nh = skb_network_header(skb);
270 unsigned int packet_len = skb_tail_pointer(skb) -
271 skb_network_header(skb);
272 int found_rhdr = 0;
273
274 *nexthdr = &ipv6_hdr(skb)->nexthdr;
275
276 while (offset + 1 <= packet_len) {
277
278 switch (**nexthdr) {
279 case NEXTHDR_HOP:
280 break;
281 case NEXTHDR_ROUTING:
282 found_rhdr = 1;
283 break;
284 case NEXTHDR_DEST:
285 /*
286 * HAO MUST NOT appear more than once.
287 * XXX: It is better to try to find by the end of
288 * XXX: packet if HAO exists.
289 */
290 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) {
291 LIMIT_NETDEBUG(KERN_WARNING "mip6: hao exists already, override\n");
292 return offset;
293 }
294
295 if (found_rhdr)
296 return offset;
297
298 break;
299 default:
300 return offset;
301 }
302
303 offset += ipv6_optlen(exthdr);
304 *nexthdr = &exthdr->nexthdr;
305 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
306 }
307
308 return offset;
309 }
310
311 static int mip6_destopt_init_state(struct xfrm_state *x)
312 {
313 if (x->id.spi) {
314 pr_info("%s: spi is not 0: %u\n", __func__, x->id.spi);
315 return -EINVAL;
316 }
317 if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
318 pr_info("%s: state's mode is not %u: %u\n",
319 __func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
320 return -EINVAL;
321 }
322
323 x->props.header_len = sizeof(struct ipv6_destopt_hdr) +
324 calc_padlen(sizeof(struct ipv6_destopt_hdr), 6) +
325 sizeof(struct ipv6_destopt_hao);
326 WARN_ON(x->props.header_len != 24);
327
328 return 0;
329 }
330
331 /*
332 * Do nothing about destroying since it has no specific operation for
333 * destination options header unlike IPsec protocols.
334 */
335 static void mip6_destopt_destroy(struct xfrm_state *x)
336 {
337 }
338
339 static const struct xfrm_type mip6_destopt_type =
340 {
341 .description = "MIP6DESTOPT",
342 .owner = THIS_MODULE,
343 .proto = IPPROTO_DSTOPTS,
344 .flags = XFRM_TYPE_NON_FRAGMENT | XFRM_TYPE_LOCAL_COADDR,
345 .init_state = mip6_destopt_init_state,
346 .destructor = mip6_destopt_destroy,
347 .input = mip6_destopt_input,
348 .output = mip6_destopt_output,
349 .reject = mip6_destopt_reject,
350 .hdr_offset = mip6_destopt_offset,
351 };
352
353 static int mip6_rthdr_input(struct xfrm_state *x, struct sk_buff *skb)
354 {
355 const struct ipv6hdr *iph = ipv6_hdr(skb);
356 struct rt2_hdr *rt2 = (struct rt2_hdr *)skb->data;
357 int err = rt2->rt_hdr.nexthdr;
358
359 spin_lock(&x->lock);
360 if (!ipv6_addr_equal(&iph->daddr, (struct in6_addr *)x->coaddr) &&
361 !ipv6_addr_any((struct in6_addr *)x->coaddr))
362 err = -ENOENT;
363 spin_unlock(&x->lock);
364
365 return err;
366 }
367
368 /* Routing Header type 2 is inserted.
369 * IP Header's dst address is replaced with Routing Header's Home Address.
370 */
371 static int mip6_rthdr_output(struct xfrm_state *x, struct sk_buff *skb)
372 {
373 struct ipv6hdr *iph;
374 struct rt2_hdr *rt2;
375 u8 nexthdr;
376
377 skb_push(skb, -skb_network_offset(skb));
378 iph = ipv6_hdr(skb);
379
380 nexthdr = *skb_mac_header(skb);
381 *skb_mac_header(skb) = IPPROTO_ROUTING;
382
383 rt2 = (struct rt2_hdr *)skb_transport_header(skb);
384 rt2->rt_hdr.nexthdr = nexthdr;
385 rt2->rt_hdr.hdrlen = (x->props.header_len >> 3) - 1;
386 rt2->rt_hdr.type = IPV6_SRCRT_TYPE_2;
387 rt2->rt_hdr.segments_left = 1;
388 memset(&rt2->reserved, 0, sizeof(rt2->reserved));
389
390 WARN_ON(rt2->rt_hdr.hdrlen != 2);
391
392 memcpy(&rt2->addr, &iph->daddr, sizeof(rt2->addr));
393 spin_lock_bh(&x->lock);
394 memcpy(&iph->daddr, x->coaddr, sizeof(iph->daddr));
395 spin_unlock_bh(&x->lock);
396
397 return 0;
398 }
399
400 static int mip6_rthdr_offset(struct xfrm_state *x, struct sk_buff *skb,
401 u8 **nexthdr)
402 {
403 u16 offset = sizeof(struct ipv6hdr);
404 struct ipv6_opt_hdr *exthdr =
405 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
406 const unsigned char *nh = skb_network_header(skb);
407 unsigned int packet_len = skb_tail_pointer(skb) -
408 skb_network_header(skb);
409 int found_rhdr = 0;
410
411 *nexthdr = &ipv6_hdr(skb)->nexthdr;
412
413 while (offset + 1 <= packet_len) {
414
415 switch (**nexthdr) {
416 case NEXTHDR_HOP:
417 break;
418 case NEXTHDR_ROUTING:
419 if (offset + 3 <= packet_len) {
420 struct ipv6_rt_hdr *rt;
421 rt = (struct ipv6_rt_hdr *)(nh + offset);
422 if (rt->type != 0)
423 return offset;
424 }
425 found_rhdr = 1;
426 break;
427 case NEXTHDR_DEST:
428 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
429 return offset;
430
431 if (found_rhdr)
432 return offset;
433
434 break;
435 default:
436 return offset;
437 }
438
439 offset += ipv6_optlen(exthdr);
440 *nexthdr = &exthdr->nexthdr;
441 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
442 }
443
444 return offset;
445 }
446
447 static int mip6_rthdr_init_state(struct xfrm_state *x)
448 {
449 if (x->id.spi) {
450 pr_info("%s: spi is not 0: %u\n", __func__, x->id.spi);
451 return -EINVAL;
452 }
453 if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
454 pr_info("%s: state's mode is not %u: %u\n",
455 __func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
456 return -EINVAL;
457 }
458
459 x->props.header_len = sizeof(struct rt2_hdr);
460
461 return 0;
462 }
463
464 /*
465 * Do nothing about destroying since it has no specific operation for routing
466 * header type 2 unlike IPsec protocols.
467 */
468 static void mip6_rthdr_destroy(struct xfrm_state *x)
469 {
470 }
471
472 static const struct xfrm_type mip6_rthdr_type =
473 {
474 .description = "MIP6RT",
475 .owner = THIS_MODULE,
476 .proto = IPPROTO_ROUTING,
477 .flags = XFRM_TYPE_NON_FRAGMENT | XFRM_TYPE_REMOTE_COADDR,
478 .init_state = mip6_rthdr_init_state,
479 .destructor = mip6_rthdr_destroy,
480 .input = mip6_rthdr_input,
481 .output = mip6_rthdr_output,
482 .hdr_offset = mip6_rthdr_offset,
483 };
484
485 static int __init mip6_init(void)
486 {
487 pr_info("Mobile IPv6\n");
488
489 if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) {
490 pr_info("%s: can't add xfrm type(destopt)\n", __func__);
491 goto mip6_destopt_xfrm_fail;
492 }
493 if (xfrm_register_type(&mip6_rthdr_type, AF_INET6) < 0) {
494 pr_info("%s: can't add xfrm type(rthdr)\n", __func__);
495 goto mip6_rthdr_xfrm_fail;
496 }
497 if (rawv6_mh_filter_register(mip6_mh_filter) < 0) {
498 pr_info("%s: can't add rawv6 mh filter\n", __func__);
499 goto mip6_rawv6_mh_fail;
500 }
501
502
503 return 0;
504
505 mip6_rawv6_mh_fail:
506 xfrm_unregister_type(&mip6_rthdr_type, AF_INET6);
507 mip6_rthdr_xfrm_fail:
508 xfrm_unregister_type(&mip6_destopt_type, AF_INET6);
509 mip6_destopt_xfrm_fail:
510 return -EAGAIN;
511 }
512
513 static void __exit mip6_fini(void)
514 {
515 if (rawv6_mh_filter_unregister(mip6_mh_filter) < 0)
516 pr_info("%s: can't remove rawv6 mh filter\n", __func__);
517 if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0)
518 pr_info("%s: can't remove xfrm type(rthdr)\n", __func__);
519 if (xfrm_unregister_type(&mip6_destopt_type, AF_INET6) < 0)
520 pr_info("%s: can't remove xfrm type(destopt)\n", __func__);
521 }
522
523 module_init(mip6_init);
524 module_exit(mip6_fini);
525
526 MODULE_LICENSE("GPL");
527 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_DSTOPTS);
528 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ROUTING);
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