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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
37static inline unsigned int calc_padlen(unsigned int len, unsigned int n)
38{
39 return (n - len + 16) & 0x7;
40}
41
42static inline void *mip6_padn(__u8 *data, __u8 padlen)
43{
44 if (!data)
45 return NULL;
46 if (padlen == 1) {
47 data[0] = IPV6_TLV_PAD0;
48 } else if (padlen > 1) {
49 data[0] = IPV6_TLV_PADN;
50 data[1] = padlen - 2;
51 if (padlen > 2)
52 memset(data+2, 0, data[1]);
53 }
54 return data + padlen;
55}
56
57static inline void mip6_param_prob(struct sk_buff *skb, u8 code, int pos)
58{
59 icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos);
60}
61
62static int mip6_mh_len(int type)
63{
64 int len = 0;
65
66 switch (type) {
67 case IP6_MH_TYPE_BRR:
68 len = 0;
69 break;
70 case IP6_MH_TYPE_HOTI:
71 case IP6_MH_TYPE_COTI:
72 case IP6_MH_TYPE_BU:
73 case IP6_MH_TYPE_BACK:
74 len = 1;
75 break;
76 case IP6_MH_TYPE_HOT:
77 case IP6_MH_TYPE_COT:
78 case IP6_MH_TYPE_BERROR:
79 len = 2;
80 break;
81 }
82 return len;
83}
84
85static int mip6_mh_filter(struct sock *sk, struct sk_buff *skb)
86{
87 struct ip6_mh *mh;
88
89 if (!pskb_may_pull(skb, (skb_transport_offset(skb)) + 8) ||
90 !pskb_may_pull(skb, (skb_transport_offset(skb) +
91 ((skb_transport_header(skb)[1] + 1) << 3))))
92 return -1;
93
94 mh = (struct ip6_mh *)skb_transport_header(skb);
95
96 if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) {
97 LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH message too short: %d vs >=%d\n",
98 mh->ip6mh_hdrlen, mip6_mh_len(mh->ip6mh_type));
99 mip6_param_prob(skb, 0, ((&mh->ip6mh_hdrlen) -
100 skb_network_header(skb)));
101 return -1;
102 }
103
104 if (mh->ip6mh_proto != IPPROTO_NONE) {
105 LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH invalid payload proto = %d\n",
106 mh->ip6mh_proto);
107 mip6_param_prob(skb, 0, ((&mh->ip6mh_proto) -
108 skb_network_header(skb)));
109 return -1;
110 }
111
112 return 0;
113}
114
115struct mip6_report_rate_limiter {
116 spinlock_t lock;
117 struct timeval stamp;
118 int iif;
119 struct in6_addr src;
120 struct in6_addr dst;
121};
122
123static struct mip6_report_rate_limiter mip6_report_rl = {
124 .lock = __SPIN_LOCK_UNLOCKED(mip6_report_rl.lock)
125};
126
127static int mip6_destopt_input(struct xfrm_state *x, struct sk_buff *skb)
128{
129 const struct ipv6hdr *iph = ipv6_hdr(skb);
130 struct ipv6_destopt_hdr *destopt = (struct ipv6_destopt_hdr *)skb->data;
131 int err = destopt->nexthdr;
132
133 spin_lock(&x->lock);
134 if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) &&
135 !ipv6_addr_any((struct in6_addr *)x->coaddr))
136 err = -ENOENT;
137 spin_unlock(&x->lock);
138
139 return err;
140}
141
142/* Destination Option Header is inserted.
143 * IP Header's src address is replaced with Home Address Option in
144 * Destination Option Header.
145 */
146static int mip6_destopt_output(struct xfrm_state *x, struct sk_buff *skb)
147{
148 struct ipv6hdr *iph;
149 struct ipv6_destopt_hdr *dstopt;
150 struct ipv6_destopt_hao *hao;
151 u8 nexthdr;
152 int len;
153
154 skb_push(skb, -skb_network_offset(skb));
155 iph = ipv6_hdr(skb);
156
157 nexthdr = *skb_mac_header(skb);
158 *skb_mac_header(skb) = IPPROTO_DSTOPTS;
159
160 dstopt = (struct ipv6_destopt_hdr *)skb_transport_header(skb);
161 dstopt->nexthdr = nexthdr;
162
163 hao = mip6_padn((char *)(dstopt + 1),
164 calc_padlen(sizeof(*dstopt), 6));
165
166 hao->type = IPV6_TLV_HAO;
167 BUILD_BUG_ON(sizeof(*hao) != 18);
168 hao->length = sizeof(*hao) - 2;
169
170 len = ((char *)hao - (char *)dstopt) + sizeof(*hao);
171
172 memcpy(&hao->addr, &iph->saddr, sizeof(hao->addr));
173 spin_lock_bh(&x->lock);
174 memcpy(&iph->saddr, x->coaddr, sizeof(iph->saddr));
175 spin_unlock_bh(&x->lock);
176
177 WARN_ON(len != x->props.header_len);
178 dstopt->hdrlen = (x->props.header_len >> 3) - 1;
179
180 return 0;
181}
182
183static inline int mip6_report_rl_allow(struct timeval *stamp,
184 const struct in6_addr *dst,
185 const 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
206static int mip6_destopt_reject(struct xfrm_state *x, struct sk_buff *skb,
207 const struct flowi *fl)
208{
209 struct net *net = xs_net(x);
210 struct inet6_skb_parm *opt = (struct inet6_skb_parm *)skb->cb;
211 const struct flowi6 *fl6 = &fl->u.ip6;
212 struct ipv6_destopt_hao *hao = NULL;
213 struct xfrm_selector sel;
214 int offset;
215 struct timeval stamp;
216 int err = 0;
217
218 if (unlikely(fl6->flowi6_proto == IPPROTO_MH &&
219 fl6->fl6_mh_type <= IP6_MH_TYPE_MAX))
220 goto out;
221
222 if (likely(opt->dsthao)) {
223 offset = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
224 if (likely(offset >= 0))
225 hao = (struct ipv6_destopt_hao *)
226 (skb_network_header(skb) + offset);
227 }
228
229 skb_get_timestamp(skb, &stamp);
230
231 if (!mip6_report_rl_allow(&stamp, &ipv6_hdr(skb)->daddr,
232 hao ? &hao->addr : &ipv6_hdr(skb)->saddr,
233 opt->iif))
234 goto out;
235
236 memset(&sel, 0, sizeof(sel));
237 memcpy(&sel.daddr, (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
238 sizeof(sel.daddr));
239 sel.prefixlen_d = 128;
240 memcpy(&sel.saddr, (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
241 sizeof(sel.saddr));
242 sel.prefixlen_s = 128;
243 sel.family = AF_INET6;
244 sel.proto = fl6->flowi6_proto;
245 sel.dport = xfrm_flowi_dport(fl, &fl6->uli);
246 if (sel.dport)
247 sel.dport_mask = htons(~0);
248 sel.sport = xfrm_flowi_sport(fl, &fl6->uli);
249 if (sel.sport)
250 sel.sport_mask = htons(~0);
251 sel.ifindex = fl6->flowi6_oif;
252
253 err = km_report(net, IPPROTO_DSTOPTS, &sel,
254 (hao ? (xfrm_address_t *)&hao->addr : NULL));
255
256 out:
257 return err;
258}
259
260static int mip6_destopt_offset(struct xfrm_state *x, struct sk_buff *skb,
261 u8 **nexthdr)
262{
263 u16 offset = sizeof(struct ipv6hdr);
264 struct ipv6_opt_hdr *exthdr =
265 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
266 const unsigned char *nh = skb_network_header(skb);
267 unsigned int packet_len = skb->tail - skb->network_header;
268 int found_rhdr = 0;
269
270 *nexthdr = &ipv6_hdr(skb)->nexthdr;
271
272 while (offset + 1 <= packet_len) {
273
274 switch (**nexthdr) {
275 case NEXTHDR_HOP:
276 break;
277 case NEXTHDR_ROUTING:
278 found_rhdr = 1;
279 break;
280 case NEXTHDR_DEST:
281 /*
282 * HAO MUST NOT appear more than once.
283 * XXX: It is better to try to find by the end of
284 * XXX: packet if HAO exists.
285 */
286 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) {
287 LIMIT_NETDEBUG(KERN_WARNING "mip6: hao exists already, override\n");
288 return offset;
289 }
290
291 if (found_rhdr)
292 return offset;
293
294 break;
295 default:
296 return offset;
297 }
298
299 offset += ipv6_optlen(exthdr);
300 *nexthdr = &exthdr->nexthdr;
301 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
302 }
303
304 return offset;
305}
306
307static int mip6_destopt_init_state(struct xfrm_state *x)
308{
309 if (x->id.spi) {
310 printk(KERN_INFO "%s: spi is not 0: %u\n", __func__,
311 x->id.spi);
312 return -EINVAL;
313 }
314 if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
315 printk(KERN_INFO "%s: state's mode is not %u: %u\n",
316 __func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
317 return -EINVAL;
318 }
319
320 x->props.header_len = sizeof(struct ipv6_destopt_hdr) +
321 calc_padlen(sizeof(struct ipv6_destopt_hdr), 6) +
322 sizeof(struct ipv6_destopt_hao);
323 WARN_ON(x->props.header_len != 24);
324
325 return 0;
326}
327
328/*
329 * Do nothing about destroying since it has no specific operation for
330 * destination options header unlike IPsec protocols.
331 */
332static void mip6_destopt_destroy(struct xfrm_state *x)
333{
334}
335
336static const struct xfrm_type mip6_destopt_type =
337{
338 .description = "MIP6DESTOPT",
339 .owner = THIS_MODULE,
340 .proto = IPPROTO_DSTOPTS,
341 .flags = XFRM_TYPE_NON_FRAGMENT | XFRM_TYPE_LOCAL_COADDR,
342 .init_state = mip6_destopt_init_state,
343 .destructor = mip6_destopt_destroy,
344 .input = mip6_destopt_input,
345 .output = mip6_destopt_output,
346 .reject = mip6_destopt_reject,
347 .hdr_offset = mip6_destopt_offset,
348};
349
350static int mip6_rthdr_input(struct xfrm_state *x, struct sk_buff *skb)
351{
352 const struct ipv6hdr *iph = ipv6_hdr(skb);
353 struct rt2_hdr *rt2 = (struct rt2_hdr *)skb->data;
354 int err = rt2->rt_hdr.nexthdr;
355
356 spin_lock(&x->lock);
357 if (!ipv6_addr_equal(&iph->daddr, (struct in6_addr *)x->coaddr) &&
358 !ipv6_addr_any((struct in6_addr *)x->coaddr))
359 err = -ENOENT;
360 spin_unlock(&x->lock);
361
362 return err;
363}
364
365/* Routing Header type 2 is inserted.
366 * IP Header's dst address is replaced with Routing Header's Home Address.
367 */
368static int mip6_rthdr_output(struct xfrm_state *x, struct sk_buff *skb)
369{
370 struct ipv6hdr *iph;
371 struct rt2_hdr *rt2;
372 u8 nexthdr;
373
374 skb_push(skb, -skb_network_offset(skb));
375 iph = ipv6_hdr(skb);
376
377 nexthdr = *skb_mac_header(skb);
378 *skb_mac_header(skb) = IPPROTO_ROUTING;
379
380 rt2 = (struct rt2_hdr *)skb_transport_header(skb);
381 rt2->rt_hdr.nexthdr = nexthdr;
382 rt2->rt_hdr.hdrlen = (x->props.header_len >> 3) - 1;
383 rt2->rt_hdr.type = IPV6_SRCRT_TYPE_2;
384 rt2->rt_hdr.segments_left = 1;
385 memset(&rt2->reserved, 0, sizeof(rt2->reserved));
386
387 WARN_ON(rt2->rt_hdr.hdrlen != 2);
388
389 memcpy(&rt2->addr, &iph->daddr, sizeof(rt2->addr));
390 spin_lock_bh(&x->lock);
391 memcpy(&iph->daddr, x->coaddr, sizeof(iph->daddr));
392 spin_unlock_bh(&x->lock);
393
394 return 0;
395}
396
397static int mip6_rthdr_offset(struct xfrm_state *x, struct sk_buff *skb,
398 u8 **nexthdr)
399{
400 u16 offset = sizeof(struct ipv6hdr);
401 struct ipv6_opt_hdr *exthdr =
402 (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
403 const unsigned char *nh = skb_network_header(skb);
404 unsigned int packet_len = skb->tail - skb->network_header;
405 int found_rhdr = 0;
406
407 *nexthdr = &ipv6_hdr(skb)->nexthdr;
408
409 while (offset + 1 <= packet_len) {
410
411 switch (**nexthdr) {
412 case NEXTHDR_HOP:
413 break;
414 case NEXTHDR_ROUTING:
415 if (offset + 3 <= packet_len) {
416 struct ipv6_rt_hdr *rt;
417 rt = (struct ipv6_rt_hdr *)(nh + offset);
418 if (rt->type != 0)
419 return offset;
420 }
421 found_rhdr = 1;
422 break;
423 case NEXTHDR_DEST:
424 if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
425 return offset;
426
427 if (found_rhdr)
428 return offset;
429
430 break;
431 default:
432 return offset;
433 }
434
435 offset += ipv6_optlen(exthdr);
436 *nexthdr = &exthdr->nexthdr;
437 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
438 }
439
440 return offset;
441}
442
443static int mip6_rthdr_init_state(struct xfrm_state *x)
444{
445 if (x->id.spi) {
446 printk(KERN_INFO "%s: spi is not 0: %u\n", __func__,
447 x->id.spi);
448 return -EINVAL;
449 }
450 if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
451 printk(KERN_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 */
465static void mip6_rthdr_destroy(struct xfrm_state *x)
466{
467}
468
469static 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
482static int __init mip6_init(void)
483{
484 printk(KERN_INFO "Mobile IPv6\n");
485
486 if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) {
487 printk(KERN_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 printk(KERN_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 printk(KERN_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
510static void __exit mip6_fini(void)
511{
512 if (rawv6_mh_filter_unregister(mip6_mh_filter) < 0)
513 printk(KERN_INFO "%s: can't remove rawv6 mh filter\n", __func__);
514 if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0)
515 printk(KERN_INFO "%s: can't remove xfrm type(rthdr)\n", __func__);
516 if (xfrm_unregister_type(&mip6_destopt_type, AF_INET6) < 0)
517 printk(KERN_INFO "%s: can't remove xfrm type(destopt)\n", __func__);
518}
519
520module_init(mip6_init);
521module_exit(mip6_fini);
522
523MODULE_LICENSE("GPL");
524MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_DSTOPTS);
525MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ROUTING);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C)2003-2006 Helsinki University of Technology
4 * Copyright (C)2003-2006 USAGI/WIDE Project
5 */
6/*
7 * Authors:
8 * Noriaki TAKAMIYA @USAGI
9 * Masahide NAKAMURA @USAGI
10 */
11
12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14#include <linux/module.h>
15#include <linux/skbuff.h>
16#include <linux/time.h>
17#include <linux/ipv6.h>
18#include <linux/icmpv6.h>
19#include <net/sock.h>
20#include <net/ipv6.h>
21#include <net/ip6_checksum.h>
22#include <net/rawv6.h>
23#include <net/xfrm.h>
24#include <net/mip6.h>
25
26static inline unsigned int calc_padlen(unsigned int len, unsigned int n)
27{
28 return (n - len + 16) & 0x7;
29}
30
31static inline void *mip6_padn(__u8 *data, __u8 padlen)
32{
33 if (!data)
34 return NULL;
35 if (padlen == 1) {
36 data[0] = IPV6_TLV_PAD1;
37 } else if (padlen > 1) {
38 data[0] = IPV6_TLV_PADN;
39 data[1] = padlen - 2;
40 if (padlen > 2)
41 memset(data+2, 0, data[1]);
42 }
43 return data + padlen;
44}
45
46static inline void mip6_param_prob(struct sk_buff *skb, u8 code, int pos)
47{
48 icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos);
49}
50
51static int mip6_mh_len(int type)
52{
53 int len = 0;
54
55 switch (type) {
56 case IP6_MH_TYPE_BRR:
57 len = 0;
58 break;
59 case IP6_MH_TYPE_HOTI:
60 case IP6_MH_TYPE_COTI:
61 case IP6_MH_TYPE_BU:
62 case IP6_MH_TYPE_BACK:
63 len = 1;
64 break;
65 case IP6_MH_TYPE_HOT:
66 case IP6_MH_TYPE_COT:
67 case IP6_MH_TYPE_BERROR:
68 len = 2;
69 break;
70 }
71 return len;
72}
73
74static int mip6_mh_filter(struct sock *sk, struct sk_buff *skb)
75{
76 struct ip6_mh _hdr;
77 const struct ip6_mh *mh;
78
79 mh = skb_header_pointer(skb, skb_transport_offset(skb),
80 sizeof(_hdr), &_hdr);
81 if (!mh)
82 return -1;
83
84 if (((mh->ip6mh_hdrlen + 1) << 3) > skb->len)
85 return -1;
86
87 if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) {
88 net_dbg_ratelimited("mip6: MH message too short: %d vs >=%d\n",
89 mh->ip6mh_hdrlen,
90 mip6_mh_len(mh->ip6mh_type));
91 mip6_param_prob(skb, 0, offsetof(struct ip6_mh, ip6mh_hdrlen) +
92 skb_network_header_len(skb));
93 return -1;
94 }
95
96 if (mh->ip6mh_proto != IPPROTO_NONE) {
97 net_dbg_ratelimited("mip6: MH invalid payload proto = %d\n",
98 mh->ip6mh_proto);
99 mip6_param_prob(skb, 0, offsetof(struct ip6_mh, ip6mh_proto) +
100 skb_network_header_len(skb));
101 return -1;
102 }
103
104 return 0;
105}
106
107struct mip6_report_rate_limiter {
108 spinlock_t lock;
109 ktime_t stamp;
110 int iif;
111 struct in6_addr src;
112 struct in6_addr dst;
113};
114
115static struct mip6_report_rate_limiter mip6_report_rl = {
116 .lock = __SPIN_LOCK_UNLOCKED(mip6_report_rl.lock)
117};
118
119static int mip6_destopt_input(struct xfrm_state *x, struct sk_buff *skb)
120{
121 const struct ipv6hdr *iph = ipv6_hdr(skb);
122 struct ipv6_destopt_hdr *destopt = (struct ipv6_destopt_hdr *)skb->data;
123 int err = destopt->nexthdr;
124
125 spin_lock(&x->lock);
126 if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) &&
127 !ipv6_addr_any((struct in6_addr *)x->coaddr))
128 err = -ENOENT;
129 spin_unlock(&x->lock);
130
131 return err;
132}
133
134/* Destination Option Header is inserted.
135 * IP Header's src address is replaced with Home Address Option in
136 * Destination Option Header.
137 */
138static int mip6_destopt_output(struct xfrm_state *x, struct sk_buff *skb)
139{
140 struct ipv6hdr *iph;
141 struct ipv6_destopt_hdr *dstopt;
142 struct ipv6_destopt_hao *hao;
143 u8 nexthdr;
144 int len;
145
146 skb_push(skb, -skb_network_offset(skb));
147 iph = ipv6_hdr(skb);
148
149 nexthdr = *skb_mac_header(skb);
150 *skb_mac_header(skb) = IPPROTO_DSTOPTS;
151
152 dstopt = (struct ipv6_destopt_hdr *)skb_transport_header(skb);
153 dstopt->nexthdr = nexthdr;
154
155 hao = mip6_padn((char *)(dstopt + 1),
156 calc_padlen(sizeof(*dstopt), 6));
157
158 hao->type = IPV6_TLV_HAO;
159 BUILD_BUG_ON(sizeof(*hao) != 18);
160 hao->length = sizeof(*hao) - 2;
161
162 len = ((char *)hao - (char *)dstopt) + sizeof(*hao);
163
164 memcpy(&hao->addr, &iph->saddr, sizeof(hao->addr));
165 spin_lock_bh(&x->lock);
166 memcpy(&iph->saddr, x->coaddr, sizeof(iph->saddr));
167 spin_unlock_bh(&x->lock);
168
169 WARN_ON(len != x->props.header_len);
170 dstopt->hdrlen = (x->props.header_len >> 3) - 1;
171
172 return 0;
173}
174
175static inline int mip6_report_rl_allow(ktime_t stamp,
176 const struct in6_addr *dst,
177 const struct in6_addr *src, int iif)
178{
179 int allow = 0;
180
181 spin_lock_bh(&mip6_report_rl.lock);
182 if (mip6_report_rl.stamp != stamp ||
183 mip6_report_rl.iif != iif ||
184 !ipv6_addr_equal(&mip6_report_rl.src, src) ||
185 !ipv6_addr_equal(&mip6_report_rl.dst, dst)) {
186 mip6_report_rl.stamp = stamp;
187 mip6_report_rl.iif = iif;
188 mip6_report_rl.src = *src;
189 mip6_report_rl.dst = *dst;
190 allow = 1;
191 }
192 spin_unlock_bh(&mip6_report_rl.lock);
193 return allow;
194}
195
196static int mip6_destopt_reject(struct xfrm_state *x, struct sk_buff *skb,
197 const struct flowi *fl)
198{
199 struct net *net = xs_net(x);
200 struct inet6_skb_parm *opt = (struct inet6_skb_parm *)skb->cb;
201 const struct flowi6 *fl6 = &fl->u.ip6;
202 struct ipv6_destopt_hao *hao = NULL;
203 struct xfrm_selector sel;
204 int offset;
205 ktime_t stamp;
206 int err = 0;
207
208 if (unlikely(fl6->flowi6_proto == IPPROTO_MH &&
209 fl6->fl6_mh_type <= IP6_MH_TYPE_MAX))
210 goto out;
211
212 if (likely(opt->dsthao)) {
213 offset = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
214 if (likely(offset >= 0))
215 hao = (struct ipv6_destopt_hao *)
216 (skb_network_header(skb) + offset);
217 }
218
219 stamp = skb_get_ktime(skb);
220
221 if (!mip6_report_rl_allow(stamp, &ipv6_hdr(skb)->daddr,
222 hao ? &hao->addr : &ipv6_hdr(skb)->saddr,
223 opt->iif))
224 goto out;
225
226 memset(&sel, 0, sizeof(sel));
227 memcpy(&sel.daddr, (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
228 sizeof(sel.daddr));
229 sel.prefixlen_d = 128;
230 memcpy(&sel.saddr, (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
231 sizeof(sel.saddr));
232 sel.prefixlen_s = 128;
233 sel.family = AF_INET6;
234 sel.proto = fl6->flowi6_proto;
235 sel.dport = xfrm_flowi_dport(fl, &fl6->uli);
236 if (sel.dport)
237 sel.dport_mask = htons(~0);
238 sel.sport = xfrm_flowi_sport(fl, &fl6->uli);
239 if (sel.sport)
240 sel.sport_mask = htons(~0);
241 sel.ifindex = fl6->flowi6_oif;
242
243 err = km_report(net, IPPROTO_DSTOPTS, &sel,
244 (hao ? (xfrm_address_t *)&hao->addr : NULL));
245
246 out:
247 return err;
248}
249
250static int mip6_destopt_init_state(struct xfrm_state *x, struct netlink_ext_ack *extack)
251{
252 if (x->id.spi) {
253 NL_SET_ERR_MSG(extack, "SPI must be 0");
254 return -EINVAL;
255 }
256 if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
257 NL_SET_ERR_MSG(extack, "XFRM mode must be XFRM_MODE_ROUTEOPTIMIZATION");
258 return -EINVAL;
259 }
260
261 x->props.header_len = sizeof(struct ipv6_destopt_hdr) +
262 calc_padlen(sizeof(struct ipv6_destopt_hdr), 6) +
263 sizeof(struct ipv6_destopt_hao);
264 WARN_ON(x->props.header_len != 24);
265
266 return 0;
267}
268
269/*
270 * Do nothing about destroying since it has no specific operation for
271 * destination options header unlike IPsec protocols.
272 */
273static void mip6_destopt_destroy(struct xfrm_state *x)
274{
275}
276
277static const struct xfrm_type mip6_destopt_type = {
278 .owner = THIS_MODULE,
279 .proto = IPPROTO_DSTOPTS,
280 .flags = XFRM_TYPE_NON_FRAGMENT | XFRM_TYPE_LOCAL_COADDR,
281 .init_state = mip6_destopt_init_state,
282 .destructor = mip6_destopt_destroy,
283 .input = mip6_destopt_input,
284 .output = mip6_destopt_output,
285 .reject = mip6_destopt_reject,
286};
287
288static int mip6_rthdr_input(struct xfrm_state *x, struct sk_buff *skb)
289{
290 const struct ipv6hdr *iph = ipv6_hdr(skb);
291 struct rt2_hdr *rt2 = (struct rt2_hdr *)skb->data;
292 int err = rt2->rt_hdr.nexthdr;
293
294 spin_lock(&x->lock);
295 if (!ipv6_addr_equal(&iph->daddr, (struct in6_addr *)x->coaddr) &&
296 !ipv6_addr_any((struct in6_addr *)x->coaddr))
297 err = -ENOENT;
298 spin_unlock(&x->lock);
299
300 return err;
301}
302
303/* Routing Header type 2 is inserted.
304 * IP Header's dst address is replaced with Routing Header's Home Address.
305 */
306static int mip6_rthdr_output(struct xfrm_state *x, struct sk_buff *skb)
307{
308 struct ipv6hdr *iph;
309 struct rt2_hdr *rt2;
310 u8 nexthdr;
311
312 skb_push(skb, -skb_network_offset(skb));
313 iph = ipv6_hdr(skb);
314
315 nexthdr = *skb_mac_header(skb);
316 *skb_mac_header(skb) = IPPROTO_ROUTING;
317
318 rt2 = (struct rt2_hdr *)skb_transport_header(skb);
319 rt2->rt_hdr.nexthdr = nexthdr;
320 rt2->rt_hdr.hdrlen = (x->props.header_len >> 3) - 1;
321 rt2->rt_hdr.type = IPV6_SRCRT_TYPE_2;
322 rt2->rt_hdr.segments_left = 1;
323 memset(&rt2->reserved, 0, sizeof(rt2->reserved));
324
325 WARN_ON(rt2->rt_hdr.hdrlen != 2);
326
327 memcpy(&rt2->addr, &iph->daddr, sizeof(rt2->addr));
328 spin_lock_bh(&x->lock);
329 memcpy(&iph->daddr, x->coaddr, sizeof(iph->daddr));
330 spin_unlock_bh(&x->lock);
331
332 return 0;
333}
334
335static int mip6_rthdr_init_state(struct xfrm_state *x, struct netlink_ext_ack *extack)
336{
337 if (x->id.spi) {
338 NL_SET_ERR_MSG(extack, "SPI must be 0");
339 return -EINVAL;
340 }
341 if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
342 NL_SET_ERR_MSG(extack, "XFRM mode must be XFRM_MODE_ROUTEOPTIMIZATION");
343 return -EINVAL;
344 }
345
346 x->props.header_len = sizeof(struct rt2_hdr);
347
348 return 0;
349}
350
351/*
352 * Do nothing about destroying since it has no specific operation for routing
353 * header type 2 unlike IPsec protocols.
354 */
355static void mip6_rthdr_destroy(struct xfrm_state *x)
356{
357}
358
359static const struct xfrm_type mip6_rthdr_type = {
360 .owner = THIS_MODULE,
361 .proto = IPPROTO_ROUTING,
362 .flags = XFRM_TYPE_NON_FRAGMENT | XFRM_TYPE_REMOTE_COADDR,
363 .init_state = mip6_rthdr_init_state,
364 .destructor = mip6_rthdr_destroy,
365 .input = mip6_rthdr_input,
366 .output = mip6_rthdr_output,
367};
368
369static int __init mip6_init(void)
370{
371 pr_info("Mobile IPv6\n");
372
373 if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) {
374 pr_info("%s: can't add xfrm type(destopt)\n", __func__);
375 goto mip6_destopt_xfrm_fail;
376 }
377 if (xfrm_register_type(&mip6_rthdr_type, AF_INET6) < 0) {
378 pr_info("%s: can't add xfrm type(rthdr)\n", __func__);
379 goto mip6_rthdr_xfrm_fail;
380 }
381 if (rawv6_mh_filter_register(mip6_mh_filter) < 0) {
382 pr_info("%s: can't add rawv6 mh filter\n", __func__);
383 goto mip6_rawv6_mh_fail;
384 }
385
386
387 return 0;
388
389 mip6_rawv6_mh_fail:
390 xfrm_unregister_type(&mip6_rthdr_type, AF_INET6);
391 mip6_rthdr_xfrm_fail:
392 xfrm_unregister_type(&mip6_destopt_type, AF_INET6);
393 mip6_destopt_xfrm_fail:
394 return -EAGAIN;
395}
396
397static void __exit mip6_fini(void)
398{
399 if (rawv6_mh_filter_unregister(mip6_mh_filter) < 0)
400 pr_info("%s: can't remove rawv6 mh filter\n", __func__);
401 xfrm_unregister_type(&mip6_rthdr_type, AF_INET6);
402 xfrm_unregister_type(&mip6_destopt_type, AF_INET6);
403}
404
405module_init(mip6_init);
406module_exit(mip6_fini);
407
408MODULE_LICENSE("GPL");
409MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_DSTOPTS);
410MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ROUTING);