Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Extension Header handling for IPv6 | |
3 | * Linux INET6 implementation | |
4 | * | |
5 | * Authors: | |
6 | * Pedro Roque <roque@di.fc.ul.pt> | |
7 | * Andi Kleen <ak@muc.de> | |
8 | * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> | |
9 | * | |
10 | * $Id: exthdrs.c,v 1.13 2001/06/19 15:58:56 davem Exp $ | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or | |
13 | * modify it under the terms of the GNU General Public License | |
14 | * as published by the Free Software Foundation; either version | |
15 | * 2 of the License, or (at your option) any later version. | |
16 | */ | |
17 | ||
18 | /* Changes: | |
19 | * yoshfuji : ensure not to overrun while parsing | |
20 | * tlv options. | |
21 | * Mitsuru KANDA @USAGI and: Remove ipv6_parse_exthdrs(). | |
22 | * YOSHIFUJI Hideaki @USAGI Register inbound extension header | |
23 | * handlers as inet6_protocol{}. | |
24 | */ | |
25 | ||
26 | #include <linux/errno.h> | |
27 | #include <linux/types.h> | |
28 | #include <linux/socket.h> | |
29 | #include <linux/sockios.h> | |
30 | #include <linux/sched.h> | |
31 | #include <linux/net.h> | |
32 | #include <linux/netdevice.h> | |
33 | #include <linux/in6.h> | |
34 | #include <linux/icmpv6.h> | |
35 | ||
36 | #include <net/sock.h> | |
37 | #include <net/snmp.h> | |
38 | ||
39 | #include <net/ipv6.h> | |
40 | #include <net/protocol.h> | |
41 | #include <net/transp_v6.h> | |
42 | #include <net/rawv6.h> | |
43 | #include <net/ndisc.h> | |
44 | #include <net/ip6_route.h> | |
45 | #include <net/addrconf.h> | |
65d4ed92 MN |
46 | #ifdef CONFIG_IPV6_MIP6 |
47 | #include <net/xfrm.h> | |
48 | #endif | |
1da177e4 LT |
49 | |
50 | #include <asm/uaccess.h> | |
51 | ||
c61a4043 MN |
52 | int ipv6_find_tlv(struct sk_buff *skb, int offset, int type) |
53 | { | |
54 | int packet_len = skb->tail - skb->nh.raw; | |
55 | struct ipv6_opt_hdr *hdr; | |
56 | int len; | |
57 | ||
58 | if (offset + 2 > packet_len) | |
59 | goto bad; | |
60 | hdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset); | |
61 | len = ((hdr->hdrlen + 1) << 3); | |
62 | ||
63 | if (offset + len > packet_len) | |
64 | goto bad; | |
65 | ||
66 | offset += 2; | |
67 | len -= 2; | |
68 | ||
69 | while (len > 0) { | |
70 | int opttype = skb->nh.raw[offset]; | |
71 | int optlen; | |
72 | ||
73 | if (opttype == type) | |
74 | return offset; | |
75 | ||
76 | switch (opttype) { | |
77 | case IPV6_TLV_PAD0: | |
78 | optlen = 1; | |
79 | break; | |
80 | default: | |
81 | optlen = skb->nh.raw[offset + 1] + 2; | |
82 | if (optlen > len) | |
83 | goto bad; | |
84 | break; | |
85 | } | |
86 | offset += optlen; | |
87 | len -= optlen; | |
88 | } | |
89 | /* not_found */ | |
c61a4043 MN |
90 | bad: |
91 | return -1; | |
92 | } | |
93 | ||
1da177e4 LT |
94 | /* |
95 | * Parsing tlv encoded headers. | |
96 | * | |
97 | * Parsing function "func" returns 1, if parsing succeed | |
98 | * and 0, if it failed. | |
99 | * It MUST NOT touch skb->h. | |
100 | */ | |
101 | ||
102 | struct tlvtype_proc { | |
103 | int type; | |
a80ff03e | 104 | int (*func)(struct sk_buff **skbp, int offset); |
1da177e4 LT |
105 | }; |
106 | ||
107 | /********************* | |
108 | Generic functions | |
109 | *********************/ | |
110 | ||
111 | /* An unknown option is detected, decide what to do */ | |
112 | ||
a80ff03e | 113 | static int ip6_tlvopt_unknown(struct sk_buff **skbp, int optoff) |
1da177e4 | 114 | { |
a80ff03e MN |
115 | struct sk_buff *skb = *skbp; |
116 | ||
1da177e4 LT |
117 | switch ((skb->nh.raw[optoff] & 0xC0) >> 6) { |
118 | case 0: /* ignore */ | |
119 | return 1; | |
120 | ||
121 | case 1: /* drop packet */ | |
122 | break; | |
123 | ||
124 | case 3: /* Send ICMP if not a multicast address and drop packet */ | |
125 | /* Actually, it is redundant check. icmp_send | |
126 | will recheck in any case. | |
127 | */ | |
128 | if (ipv6_addr_is_multicast(&skb->nh.ipv6h->daddr)) | |
129 | break; | |
130 | case 2: /* send ICMP PARM PROB regardless and drop packet */ | |
131 | icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff); | |
132 | return 0; | |
133 | }; | |
134 | ||
135 | kfree_skb(skb); | |
136 | return 0; | |
137 | } | |
138 | ||
139 | /* Parse tlv encoded option header (hop-by-hop or destination) */ | |
140 | ||
a80ff03e | 141 | static int ip6_parse_tlv(struct tlvtype_proc *procs, struct sk_buff **skbp) |
1da177e4 | 142 | { |
a80ff03e | 143 | struct sk_buff *skb = *skbp; |
1da177e4 LT |
144 | struct tlvtype_proc *curr; |
145 | int off = skb->h.raw - skb->nh.raw; | |
146 | int len = ((skb->h.raw[1]+1)<<3); | |
147 | ||
148 | if ((skb->h.raw + len) - skb->data > skb_headlen(skb)) | |
149 | goto bad; | |
150 | ||
151 | off += 2; | |
152 | len -= 2; | |
153 | ||
154 | while (len > 0) { | |
155 | int optlen = skb->nh.raw[off+1]+2; | |
156 | ||
157 | switch (skb->nh.raw[off]) { | |
158 | case IPV6_TLV_PAD0: | |
159 | optlen = 1; | |
160 | break; | |
161 | ||
162 | case IPV6_TLV_PADN: | |
163 | break; | |
164 | ||
165 | default: /* Other TLV code so scan list */ | |
166 | if (optlen > len) | |
167 | goto bad; | |
168 | for (curr=procs; curr->type >= 0; curr++) { | |
169 | if (curr->type == skb->nh.raw[off]) { | |
170 | /* type specific length/alignment | |
171 | checks will be performed in the | |
172 | func(). */ | |
a80ff03e | 173 | if (curr->func(skbp, off) == 0) |
1da177e4 LT |
174 | return 0; |
175 | break; | |
176 | } | |
177 | } | |
178 | if (curr->type < 0) { | |
a80ff03e | 179 | if (ip6_tlvopt_unknown(skbp, off) == 0) |
1da177e4 LT |
180 | return 0; |
181 | } | |
182 | break; | |
183 | } | |
184 | off += optlen; | |
185 | len -= optlen; | |
186 | } | |
187 | if (len == 0) | |
188 | return 1; | |
189 | bad: | |
190 | kfree_skb(skb); | |
191 | return 0; | |
192 | } | |
193 | ||
194 | /***************************** | |
195 | Destination options header. | |
196 | *****************************/ | |
197 | ||
a831f5bb MN |
198 | #ifdef CONFIG_IPV6_MIP6 |
199 | static int ipv6_dest_hao(struct sk_buff **skbp, int optoff) | |
200 | { | |
201 | struct sk_buff *skb = *skbp; | |
202 | struct ipv6_destopt_hao *hao; | |
203 | struct inet6_skb_parm *opt = IP6CB(skb); | |
204 | struct ipv6hdr *ipv6h = (struct ipv6hdr *)skb->nh.raw; | |
205 | struct in6_addr tmp_addr; | |
206 | int ret; | |
207 | ||
208 | if (opt->dsthao) { | |
209 | LIMIT_NETDEBUG(KERN_DEBUG "hao duplicated\n"); | |
210 | goto discard; | |
211 | } | |
212 | opt->dsthao = opt->dst1; | |
213 | opt->dst1 = 0; | |
214 | ||
215 | hao = (struct ipv6_destopt_hao *)(skb->nh.raw + optoff); | |
216 | ||
217 | if (hao->length != 16) { | |
218 | LIMIT_NETDEBUG( | |
219 | KERN_DEBUG "hao invalid option length = %d\n", hao->length); | |
220 | goto discard; | |
221 | } | |
222 | ||
223 | if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) { | |
224 | LIMIT_NETDEBUG( | |
225 | KERN_DEBUG "hao is not an unicast addr: " NIP6_FMT "\n", NIP6(hao->addr)); | |
226 | goto discard; | |
227 | } | |
228 | ||
229 | ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr, | |
230 | (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS); | |
231 | if (unlikely(ret < 0)) | |
232 | goto discard; | |
233 | ||
234 | if (skb_cloned(skb)) { | |
235 | struct sk_buff *skb2 = skb_copy(skb, GFP_ATOMIC); | |
236 | if (skb2 == NULL) | |
237 | goto discard; | |
238 | ||
239 | kfree_skb(skb); | |
240 | ||
241 | /* update all variable using below by copied skbuff */ | |
242 | *skbp = skb = skb2; | |
243 | hao = (struct ipv6_destopt_hao *)(skb2->nh.raw + optoff); | |
244 | ipv6h = (struct ipv6hdr *)skb2->nh.raw; | |
245 | } | |
246 | ||
247 | if (skb->ip_summed == CHECKSUM_COMPLETE) | |
248 | skb->ip_summed = CHECKSUM_NONE; | |
249 | ||
250 | ipv6_addr_copy(&tmp_addr, &ipv6h->saddr); | |
251 | ipv6_addr_copy(&ipv6h->saddr, &hao->addr); | |
252 | ipv6_addr_copy(&hao->addr, &tmp_addr); | |
253 | ||
254 | if (skb->tstamp.off_sec == 0) | |
255 | __net_timestamp(skb); | |
256 | ||
257 | return 1; | |
258 | ||
259 | discard: | |
260 | kfree_skb(skb); | |
261 | return 0; | |
262 | } | |
263 | #endif | |
264 | ||
1da177e4 | 265 | static struct tlvtype_proc tlvprocdestopt_lst[] = { |
a831f5bb MN |
266 | #ifdef CONFIG_IPV6_MIP6 |
267 | { | |
268 | .type = IPV6_TLV_HAO, | |
269 | .func = ipv6_dest_hao, | |
270 | }, | |
271 | #endif | |
1da177e4 LT |
272 | {-1, NULL} |
273 | }; | |
274 | ||
951dbc8a | 275 | static int ipv6_destopt_rcv(struct sk_buff **skbp) |
1da177e4 LT |
276 | { |
277 | struct sk_buff *skb = *skbp; | |
278 | struct inet6_skb_parm *opt = IP6CB(skb); | |
a831f5bb MN |
279 | #ifdef CONFIG_IPV6_MIP6 |
280 | __u16 dstbuf; | |
281 | #endif | |
1da177e4 LT |
282 | |
283 | if (!pskb_may_pull(skb, (skb->h.raw-skb->data)+8) || | |
284 | !pskb_may_pull(skb, (skb->h.raw-skb->data)+((skb->h.raw[1]+1)<<3))) { | |
285 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); | |
286 | kfree_skb(skb); | |
287 | return -1; | |
288 | } | |
289 | ||
333fad53 | 290 | opt->lastopt = skb->h.raw - skb->nh.raw; |
1da177e4 | 291 | opt->dst1 = skb->h.raw - skb->nh.raw; |
a831f5bb MN |
292 | #ifdef CONFIG_IPV6_MIP6 |
293 | dstbuf = opt->dst1; | |
294 | #endif | |
1da177e4 | 295 | |
a80ff03e MN |
296 | if (ip6_parse_tlv(tlvprocdestopt_lst, skbp)) { |
297 | skb = *skbp; | |
1da177e4 | 298 | skb->h.raw += ((skb->h.raw[1]+1)<<3); |
a831f5bb MN |
299 | #ifdef CONFIG_IPV6_MIP6 |
300 | opt->nhoff = dstbuf; | |
301 | #else | |
951dbc8a | 302 | opt->nhoff = opt->dst1; |
a831f5bb | 303 | #endif |
1da177e4 LT |
304 | return 1; |
305 | } | |
306 | ||
307 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); | |
308 | return -1; | |
309 | } | |
310 | ||
311 | static struct inet6_protocol destopt_protocol = { | |
312 | .handler = ipv6_destopt_rcv, | |
adcfc7d0 | 313 | .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR, |
1da177e4 LT |
314 | }; |
315 | ||
316 | void __init ipv6_destopt_init(void) | |
317 | { | |
318 | if (inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS) < 0) | |
319 | printk(KERN_ERR "ipv6_destopt_init: Could not register protocol\n"); | |
320 | } | |
321 | ||
322 | /******************************** | |
323 | NONE header. No data in packet. | |
324 | ********************************/ | |
325 | ||
951dbc8a | 326 | static int ipv6_nodata_rcv(struct sk_buff **skbp) |
1da177e4 LT |
327 | { |
328 | struct sk_buff *skb = *skbp; | |
329 | ||
330 | kfree_skb(skb); | |
331 | return 0; | |
332 | } | |
333 | ||
334 | static struct inet6_protocol nodata_protocol = { | |
335 | .handler = ipv6_nodata_rcv, | |
336 | .flags = INET6_PROTO_NOPOLICY, | |
337 | }; | |
338 | ||
339 | void __init ipv6_nodata_init(void) | |
340 | { | |
341 | if (inet6_add_protocol(&nodata_protocol, IPPROTO_NONE) < 0) | |
342 | printk(KERN_ERR "ipv6_nodata_init: Could not register protocol\n"); | |
343 | } | |
344 | ||
345 | /******************************** | |
346 | Routing header. | |
347 | ********************************/ | |
348 | ||
951dbc8a | 349 | static int ipv6_rthdr_rcv(struct sk_buff **skbp) |
1da177e4 LT |
350 | { |
351 | struct sk_buff *skb = *skbp; | |
352 | struct inet6_skb_parm *opt = IP6CB(skb); | |
65d4ed92 | 353 | struct in6_addr *addr = NULL; |
1da177e4 LT |
354 | struct in6_addr daddr; |
355 | int n, i; | |
356 | ||
357 | struct ipv6_rt_hdr *hdr; | |
358 | struct rt0_hdr *rthdr; | |
359 | ||
360 | if (!pskb_may_pull(skb, (skb->h.raw-skb->data)+8) || | |
361 | !pskb_may_pull(skb, (skb->h.raw-skb->data)+((skb->h.raw[1]+1)<<3))) { | |
362 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); | |
363 | kfree_skb(skb); | |
364 | return -1; | |
365 | } | |
366 | ||
367 | hdr = (struct ipv6_rt_hdr *) skb->h.raw; | |
368 | ||
369 | if (ipv6_addr_is_multicast(&skb->nh.ipv6h->daddr) || | |
370 | skb->pkt_type != PACKET_HOST) { | |
371 | IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS); | |
372 | kfree_skb(skb); | |
373 | return -1; | |
374 | } | |
375 | ||
376 | looped_back: | |
377 | if (hdr->segments_left == 0) { | |
65d4ed92 MN |
378 | switch (hdr->type) { |
379 | #ifdef CONFIG_IPV6_MIP6 | |
380 | case IPV6_SRCRT_TYPE_2: | |
381 | /* Silently discard type 2 header unless it was | |
382 | * processed by own | |
383 | */ | |
384 | if (!addr) { | |
385 | IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS); | |
386 | kfree_skb(skb); | |
387 | return -1; | |
388 | } | |
389 | break; | |
390 | #endif | |
391 | default: | |
392 | break; | |
393 | } | |
394 | ||
333fad53 | 395 | opt->lastopt = skb->h.raw - skb->nh.raw; |
1da177e4 LT |
396 | opt->srcrt = skb->h.raw - skb->nh.raw; |
397 | skb->h.raw += (hdr->hdrlen + 1) << 3; | |
398 | opt->dst0 = opt->dst1; | |
399 | opt->dst1 = 0; | |
951dbc8a | 400 | opt->nhoff = (&hdr->nexthdr) - skb->nh.raw; |
1da177e4 LT |
401 | return 1; |
402 | } | |
403 | ||
65d4ed92 MN |
404 | switch (hdr->type) { |
405 | case IPV6_SRCRT_TYPE_0: | |
406 | if (hdr->hdrlen & 0x01) { | |
407 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); | |
408 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, (&hdr->hdrlen) - skb->nh.raw); | |
409 | return -1; | |
410 | } | |
411 | break; | |
412 | #ifdef CONFIG_IPV6_MIP6 | |
413 | case IPV6_SRCRT_TYPE_2: | |
414 | /* Silently discard invalid RTH type 2 */ | |
415 | if (hdr->hdrlen != 2 || hdr->segments_left != 1) { | |
416 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); | |
417 | kfree_skb(skb); | |
418 | return -1; | |
419 | } | |
420 | break; | |
421 | #endif | |
422 | default: | |
1da177e4 LT |
423 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); |
424 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, (&hdr->type) - skb->nh.raw); | |
425 | return -1; | |
426 | } | |
1da177e4 LT |
427 | |
428 | /* | |
429 | * This is the routing header forwarding algorithm from | |
430 | * RFC 2460, page 16. | |
431 | */ | |
432 | ||
433 | n = hdr->hdrlen >> 1; | |
434 | ||
435 | if (hdr->segments_left > n) { | |
436 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); | |
437 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, (&hdr->segments_left) - skb->nh.raw); | |
438 | return -1; | |
439 | } | |
440 | ||
441 | /* We are about to mangle packet header. Be careful! | |
442 | Do not damage packets queued somewhere. | |
443 | */ | |
444 | if (skb_cloned(skb)) { | |
445 | struct sk_buff *skb2 = skb_copy(skb, GFP_ATOMIC); | |
446 | kfree_skb(skb); | |
447 | /* the copy is a forwarded packet */ | |
448 | if (skb2 == NULL) { | |
449 | IP6_INC_STATS_BH(IPSTATS_MIB_OUTDISCARDS); | |
450 | return -1; | |
451 | } | |
452 | *skbp = skb = skb2; | |
453 | opt = IP6CB(skb2); | |
454 | hdr = (struct ipv6_rt_hdr *) skb2->h.raw; | |
455 | } | |
456 | ||
84fa7933 | 457 | if (skb->ip_summed == CHECKSUM_COMPLETE) |
1da177e4 LT |
458 | skb->ip_summed = CHECKSUM_NONE; |
459 | ||
460 | i = n - --hdr->segments_left; | |
461 | ||
462 | rthdr = (struct rt0_hdr *) hdr; | |
463 | addr = rthdr->addr; | |
464 | addr += i - 1; | |
465 | ||
65d4ed92 MN |
466 | switch (hdr->type) { |
467 | #ifdef CONFIG_IPV6_MIP6 | |
468 | case IPV6_SRCRT_TYPE_2: | |
469 | if (xfrm6_input_addr(skb, (xfrm_address_t *)addr, | |
470 | (xfrm_address_t *)&skb->nh.ipv6h->saddr, | |
471 | IPPROTO_ROUTING) < 0) { | |
472 | IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS); | |
473 | kfree_skb(skb); | |
474 | return -1; | |
475 | } | |
476 | if (!ipv6_chk_home_addr(addr)) { | |
477 | IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS); | |
478 | kfree_skb(skb); | |
479 | return -1; | |
480 | } | |
481 | break; | |
482 | #endif | |
483 | default: | |
484 | break; | |
485 | } | |
486 | ||
1da177e4 LT |
487 | if (ipv6_addr_is_multicast(addr)) { |
488 | IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS); | |
489 | kfree_skb(skb); | |
490 | return -1; | |
491 | } | |
492 | ||
493 | ipv6_addr_copy(&daddr, addr); | |
494 | ipv6_addr_copy(addr, &skb->nh.ipv6h->daddr); | |
495 | ipv6_addr_copy(&skb->nh.ipv6h->daddr, &daddr); | |
496 | ||
497 | dst_release(xchg(&skb->dst, NULL)); | |
498 | ip6_route_input(skb); | |
499 | if (skb->dst->error) { | |
500 | skb_push(skb, skb->data - skb->nh.raw); | |
501 | dst_input(skb); | |
502 | return -1; | |
503 | } | |
504 | ||
505 | if (skb->dst->dev->flags&IFF_LOOPBACK) { | |
506 | if (skb->nh.ipv6h->hop_limit <= 1) { | |
507 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); | |
508 | icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, | |
509 | 0, skb->dev); | |
510 | kfree_skb(skb); | |
511 | return -1; | |
512 | } | |
513 | skb->nh.ipv6h->hop_limit--; | |
514 | goto looped_back; | |
515 | } | |
516 | ||
517 | skb_push(skb, skb->data - skb->nh.raw); | |
518 | dst_input(skb); | |
519 | return -1; | |
520 | } | |
521 | ||
522 | static struct inet6_protocol rthdr_protocol = { | |
523 | .handler = ipv6_rthdr_rcv, | |
adcfc7d0 | 524 | .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR, |
1da177e4 LT |
525 | }; |
526 | ||
527 | void __init ipv6_rthdr_init(void) | |
528 | { | |
529 | if (inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING) < 0) | |
530 | printk(KERN_ERR "ipv6_rthdr_init: Could not register protocol\n"); | |
531 | }; | |
532 | ||
533 | /* | |
534 | This function inverts received rthdr. | |
535 | NOTE: specs allow to make it automatically only if | |
536 | packet authenticated. | |
537 | ||
538 | I will not discuss it here (though, I am really pissed off at | |
539 | this stupid requirement making rthdr idea useless) | |
540 | ||
541 | Actually, it creates severe problems for us. | |
542 | Embryonic requests has no associated sockets, | |
543 | so that user have no control over it and | |
544 | cannot not only to set reply options, but | |
545 | even to know, that someone wants to connect | |
546 | without success. :-( | |
547 | ||
548 | For now we need to test the engine, so that I created | |
549 | temporary (or permanent) backdoor. | |
550 | If listening socket set IPV6_RTHDR to 2, then we invert header. | |
551 | --ANK (980729) | |
552 | */ | |
553 | ||
554 | struct ipv6_txoptions * | |
555 | ipv6_invert_rthdr(struct sock *sk, struct ipv6_rt_hdr *hdr) | |
556 | { | |
557 | /* Received rthdr: | |
558 | ||
559 | [ H1 -> H2 -> ... H_prev ] daddr=ME | |
560 | ||
561 | Inverted result: | |
562 | [ H_prev -> ... -> H1 ] daddr =sender | |
563 | ||
564 | Note, that IP output engine will rewrite this rthdr | |
565 | by rotating it left by one addr. | |
566 | */ | |
567 | ||
568 | int n, i; | |
569 | struct rt0_hdr *rthdr = (struct rt0_hdr*)hdr; | |
570 | struct rt0_hdr *irthdr; | |
571 | struct ipv6_txoptions *opt; | |
572 | int hdrlen = ipv6_optlen(hdr); | |
573 | ||
574 | if (hdr->segments_left || | |
575 | hdr->type != IPV6_SRCRT_TYPE_0 || | |
576 | hdr->hdrlen & 0x01) | |
577 | return NULL; | |
578 | ||
579 | n = hdr->hdrlen >> 1; | |
580 | opt = sock_kmalloc(sk, sizeof(*opt) + hdrlen, GFP_ATOMIC); | |
581 | if (opt == NULL) | |
582 | return NULL; | |
583 | memset(opt, 0, sizeof(*opt)); | |
584 | opt->tot_len = sizeof(*opt) + hdrlen; | |
585 | opt->srcrt = (void*)(opt+1); | |
586 | opt->opt_nflen = hdrlen; | |
587 | ||
588 | memcpy(opt->srcrt, hdr, sizeof(*hdr)); | |
589 | irthdr = (struct rt0_hdr*)opt->srcrt; | |
e6df439b | 590 | irthdr->reserved = 0; |
1da177e4 LT |
591 | opt->srcrt->segments_left = n; |
592 | for (i=0; i<n; i++) | |
593 | memcpy(irthdr->addr+i, rthdr->addr+(n-1-i), 16); | |
594 | return opt; | |
595 | } | |
596 | ||
3cf3dc6c ACM |
597 | EXPORT_SYMBOL_GPL(ipv6_invert_rthdr); |
598 | ||
1da177e4 LT |
599 | /********************************** |
600 | Hop-by-hop options. | |
601 | **********************************/ | |
602 | ||
603 | /* Router Alert as of RFC 2711 */ | |
604 | ||
a80ff03e | 605 | static int ipv6_hop_ra(struct sk_buff **skbp, int optoff) |
1da177e4 | 606 | { |
a80ff03e MN |
607 | struct sk_buff *skb = *skbp; |
608 | ||
1da177e4 LT |
609 | if (skb->nh.raw[optoff+1] == 2) { |
610 | IP6CB(skb)->ra = optoff; | |
611 | return 1; | |
612 | } | |
64ce2073 PM |
613 | LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_ra: wrong RA length %d\n", |
614 | skb->nh.raw[optoff+1]); | |
1da177e4 LT |
615 | kfree_skb(skb); |
616 | return 0; | |
617 | } | |
618 | ||
619 | /* Jumbo payload */ | |
620 | ||
a80ff03e | 621 | static int ipv6_hop_jumbo(struct sk_buff **skbp, int optoff) |
1da177e4 | 622 | { |
a80ff03e | 623 | struct sk_buff *skb = *skbp; |
1da177e4 LT |
624 | u32 pkt_len; |
625 | ||
626 | if (skb->nh.raw[optoff+1] != 4 || (optoff&3) != 2) { | |
64ce2073 PM |
627 | LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n", |
628 | skb->nh.raw[optoff+1]); | |
1da177e4 LT |
629 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); |
630 | goto drop; | |
631 | } | |
632 | ||
633 | pkt_len = ntohl(*(u32*)(skb->nh.raw+optoff+2)); | |
634 | if (pkt_len <= IPV6_MAXPLEN) { | |
635 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); | |
636 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2); | |
637 | return 0; | |
638 | } | |
639 | if (skb->nh.ipv6h->payload_len) { | |
640 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); | |
641 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff); | |
642 | return 0; | |
643 | } | |
644 | ||
645 | if (pkt_len > skb->len - sizeof(struct ipv6hdr)) { | |
646 | IP6_INC_STATS_BH(IPSTATS_MIB_INTRUNCATEDPKTS); | |
647 | goto drop; | |
648 | } | |
42ca89c1 SH |
649 | |
650 | if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) | |
651 | goto drop; | |
652 | ||
1da177e4 LT |
653 | return 1; |
654 | ||
655 | drop: | |
656 | kfree_skb(skb); | |
657 | return 0; | |
658 | } | |
659 | ||
660 | static struct tlvtype_proc tlvprochopopt_lst[] = { | |
661 | { | |
662 | .type = IPV6_TLV_ROUTERALERT, | |
663 | .func = ipv6_hop_ra, | |
664 | }, | |
665 | { | |
666 | .type = IPV6_TLV_JUMBO, | |
667 | .func = ipv6_hop_jumbo, | |
668 | }, | |
669 | { -1, } | |
670 | }; | |
671 | ||
a80ff03e | 672 | int ipv6_parse_hopopts(struct sk_buff **skbp) |
1da177e4 | 673 | { |
a80ff03e | 674 | struct sk_buff *skb = *skbp; |
951dbc8a PM |
675 | struct inet6_skb_parm *opt = IP6CB(skb); |
676 | ||
ec670095 YH |
677 | /* |
678 | * skb->nh.raw is equal to skb->data, and | |
679 | * skb->h.raw - skb->nh.raw is always equal to | |
680 | * sizeof(struct ipv6hdr) by definition of | |
681 | * hop-by-hop options. | |
682 | */ | |
683 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) || | |
684 | !pskb_may_pull(skb, sizeof(struct ipv6hdr) + ((skb->h.raw[1] + 1) << 3))) { | |
685 | kfree_skb(skb); | |
686 | return -1; | |
687 | } | |
688 | ||
951dbc8a | 689 | opt->hop = sizeof(struct ipv6hdr); |
a80ff03e MN |
690 | if (ip6_parse_tlv(tlvprochopopt_lst, skbp)) { |
691 | skb = *skbp; | |
951dbc8a PM |
692 | skb->h.raw += (skb->h.raw[1]+1)<<3; |
693 | opt->nhoff = sizeof(struct ipv6hdr); | |
b809739a | 694 | return 1; |
951dbc8a | 695 | } |
1da177e4 LT |
696 | return -1; |
697 | } | |
698 | ||
699 | /* | |
700 | * Creating outbound headers. | |
701 | * | |
702 | * "build" functions work when skb is filled from head to tail (datagram) | |
703 | * "push" functions work when headers are added from tail to head (tcp) | |
704 | * | |
705 | * In both cases we assume, that caller reserved enough room | |
706 | * for headers. | |
707 | */ | |
708 | ||
709 | static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto, | |
710 | struct ipv6_rt_hdr *opt, | |
711 | struct in6_addr **addr_p) | |
712 | { | |
713 | struct rt0_hdr *phdr, *ihdr; | |
714 | int hops; | |
715 | ||
716 | ihdr = (struct rt0_hdr *) opt; | |
717 | ||
718 | phdr = (struct rt0_hdr *) skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3); | |
719 | memcpy(phdr, ihdr, sizeof(struct rt0_hdr)); | |
720 | ||
721 | hops = ihdr->rt_hdr.hdrlen >> 1; | |
722 | ||
723 | if (hops > 1) | |
724 | memcpy(phdr->addr, ihdr->addr + 1, | |
725 | (hops - 1) * sizeof(struct in6_addr)); | |
726 | ||
727 | ipv6_addr_copy(phdr->addr + (hops - 1), *addr_p); | |
728 | *addr_p = ihdr->addr; | |
729 | ||
730 | phdr->rt_hdr.nexthdr = *proto; | |
731 | *proto = NEXTHDR_ROUTING; | |
732 | } | |
733 | ||
734 | static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt) | |
735 | { | |
736 | struct ipv6_opt_hdr *h = (struct ipv6_opt_hdr *)skb_push(skb, ipv6_optlen(opt)); | |
737 | ||
738 | memcpy(h, opt, ipv6_optlen(opt)); | |
739 | h->nexthdr = *proto; | |
740 | *proto = type; | |
741 | } | |
742 | ||
743 | void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, | |
744 | u8 *proto, | |
745 | struct in6_addr **daddr) | |
746 | { | |
333fad53 | 747 | if (opt->srcrt) { |
1da177e4 | 748 | ipv6_push_rthdr(skb, proto, opt->srcrt, daddr); |
333fad53 YH |
749 | /* |
750 | * IPV6_RTHDRDSTOPTS is ignored | |
751 | * unless IPV6_RTHDR is set (RFC3542). | |
752 | */ | |
753 | if (opt->dst0opt) | |
754 | ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt); | |
755 | } | |
1da177e4 LT |
756 | if (opt->hopopt) |
757 | ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt); | |
758 | } | |
759 | ||
760 | void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto) | |
761 | { | |
762 | if (opt->dst1opt) | |
763 | ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt); | |
764 | } | |
765 | ||
766 | struct ipv6_txoptions * | |
767 | ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt) | |
768 | { | |
769 | struct ipv6_txoptions *opt2; | |
770 | ||
771 | opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC); | |
772 | if (opt2) { | |
773 | long dif = (char*)opt2 - (char*)opt; | |
774 | memcpy(opt2, opt, opt->tot_len); | |
775 | if (opt2->hopopt) | |
776 | *((char**)&opt2->hopopt) += dif; | |
777 | if (opt2->dst0opt) | |
778 | *((char**)&opt2->dst0opt) += dif; | |
779 | if (opt2->dst1opt) | |
780 | *((char**)&opt2->dst1opt) += dif; | |
781 | if (opt2->srcrt) | |
782 | *((char**)&opt2->srcrt) += dif; | |
783 | } | |
784 | return opt2; | |
785 | } | |
333fad53 | 786 | |
3cf3dc6c ACM |
787 | EXPORT_SYMBOL_GPL(ipv6_dup_options); |
788 | ||
333fad53 YH |
789 | static int ipv6_renew_option(void *ohdr, |
790 | struct ipv6_opt_hdr __user *newopt, int newoptlen, | |
791 | int inherit, | |
792 | struct ipv6_opt_hdr **hdr, | |
793 | char **p) | |
794 | { | |
795 | if (inherit) { | |
796 | if (ohdr) { | |
797 | memcpy(*p, ohdr, ipv6_optlen((struct ipv6_opt_hdr *)ohdr)); | |
798 | *hdr = (struct ipv6_opt_hdr *)*p; | |
799 | *p += CMSG_ALIGN(ipv6_optlen(*(struct ipv6_opt_hdr **)hdr)); | |
800 | } | |
801 | } else { | |
802 | if (newopt) { | |
803 | if (copy_from_user(*p, newopt, newoptlen)) | |
804 | return -EFAULT; | |
805 | *hdr = (struct ipv6_opt_hdr *)*p; | |
806 | if (ipv6_optlen(*(struct ipv6_opt_hdr **)hdr) > newoptlen) | |
807 | return -EINVAL; | |
808 | *p += CMSG_ALIGN(newoptlen); | |
809 | } | |
810 | } | |
811 | return 0; | |
812 | } | |
813 | ||
814 | struct ipv6_txoptions * | |
815 | ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt, | |
816 | int newtype, | |
817 | struct ipv6_opt_hdr __user *newopt, int newoptlen) | |
818 | { | |
819 | int tot_len = 0; | |
820 | char *p; | |
821 | struct ipv6_txoptions *opt2; | |
822 | int err; | |
823 | ||
99c7bc01 YH |
824 | if (opt) { |
825 | if (newtype != IPV6_HOPOPTS && opt->hopopt) | |
826 | tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt)); | |
827 | if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt) | |
828 | tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt)); | |
829 | if (newtype != IPV6_RTHDR && opt->srcrt) | |
830 | tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt)); | |
831 | if (newtype != IPV6_DSTOPTS && opt->dst1opt) | |
832 | tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt)); | |
833 | } | |
834 | ||
333fad53 YH |
835 | if (newopt && newoptlen) |
836 | tot_len += CMSG_ALIGN(newoptlen); | |
837 | ||
838 | if (!tot_len) | |
839 | return NULL; | |
840 | ||
8b8aa4b5 | 841 | tot_len += sizeof(*opt2); |
333fad53 YH |
842 | opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC); |
843 | if (!opt2) | |
844 | return ERR_PTR(-ENOBUFS); | |
845 | ||
846 | memset(opt2, 0, tot_len); | |
847 | ||
848 | opt2->tot_len = tot_len; | |
849 | p = (char *)(opt2 + 1); | |
850 | ||
99c7bc01 | 851 | err = ipv6_renew_option(opt ? opt->hopopt : NULL, newopt, newoptlen, |
333fad53 YH |
852 | newtype != IPV6_HOPOPTS, |
853 | &opt2->hopopt, &p); | |
854 | if (err) | |
855 | goto out; | |
856 | ||
99c7bc01 | 857 | err = ipv6_renew_option(opt ? opt->dst0opt : NULL, newopt, newoptlen, |
333fad53 YH |
858 | newtype != IPV6_RTHDRDSTOPTS, |
859 | &opt2->dst0opt, &p); | |
860 | if (err) | |
861 | goto out; | |
862 | ||
99c7bc01 | 863 | err = ipv6_renew_option(opt ? opt->srcrt : NULL, newopt, newoptlen, |
333fad53 | 864 | newtype != IPV6_RTHDR, |
99c7bc01 | 865 | (struct ipv6_opt_hdr **)&opt2->srcrt, &p); |
333fad53 YH |
866 | if (err) |
867 | goto out; | |
868 | ||
99c7bc01 | 869 | err = ipv6_renew_option(opt ? opt->dst1opt : NULL, newopt, newoptlen, |
333fad53 YH |
870 | newtype != IPV6_DSTOPTS, |
871 | &opt2->dst1opt, &p); | |
872 | if (err) | |
873 | goto out; | |
874 | ||
875 | opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) + | |
876 | (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) + | |
877 | (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0); | |
878 | opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0); | |
879 | ||
880 | return opt2; | |
881 | out: | |
8b8aa4b5 | 882 | sock_kfree_s(sk, opt2, opt2->tot_len); |
333fad53 YH |
883 | return ERR_PTR(err); |
884 | } | |
885 | ||
df9890c3 YH |
886 | struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space, |
887 | struct ipv6_txoptions *opt) | |
888 | { | |
889 | /* | |
890 | * ignore the dest before srcrt unless srcrt is being included. | |
891 | * --yoshfuji | |
892 | */ | |
893 | if (opt && opt->dst0opt && !opt->srcrt) { | |
894 | if (opt_space != opt) { | |
895 | memcpy(opt_space, opt, sizeof(*opt_space)); | |
896 | opt = opt_space; | |
897 | } | |
898 | opt->opt_nflen -= ipv6_optlen(opt->dst0opt); | |
899 | opt->dst0opt = NULL; | |
900 | } | |
901 | ||
902 | return opt; | |
903 | } | |
904 |