~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/ipv6/mip6.c

Version: ~ [ linux-5.8 ] ~ [ linux-5.7.14 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.57 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.138 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.193 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.232 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.232 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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);
529 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp