Commit | Line | Data |
---|---|---|
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); | |
dc435e6d MN |
236 | struct inet6_skb_parm *opt2; |
237 | ||
a831f5bb MN |
238 | if (skb2 == NULL) |
239 | goto discard; | |
240 | ||
dc435e6d MN |
241 | opt2 = IP6CB(skb2); |
242 | memcpy(opt2, opt, sizeof(*opt2)); | |
243 | ||
a831f5bb MN |
244 | kfree_skb(skb); |
245 | ||
246 | /* update all variable using below by copied skbuff */ | |
247 | *skbp = skb = skb2; | |
248 | hao = (struct ipv6_destopt_hao *)(skb2->nh.raw + optoff); | |
249 | ipv6h = (struct ipv6hdr *)skb2->nh.raw; | |
250 | } | |
251 | ||
252 | if (skb->ip_summed == CHECKSUM_COMPLETE) | |
253 | skb->ip_summed = CHECKSUM_NONE; | |
254 | ||
255 | ipv6_addr_copy(&tmp_addr, &ipv6h->saddr); | |
256 | ipv6_addr_copy(&ipv6h->saddr, &hao->addr); | |
257 | ipv6_addr_copy(&hao->addr, &tmp_addr); | |
258 | ||
259 | if (skb->tstamp.off_sec == 0) | |
260 | __net_timestamp(skb); | |
261 | ||
262 | return 1; | |
263 | ||
264 | discard: | |
265 | kfree_skb(skb); | |
266 | return 0; | |
267 | } | |
268 | #endif | |
269 | ||
1da177e4 | 270 | static struct tlvtype_proc tlvprocdestopt_lst[] = { |
a831f5bb MN |
271 | #ifdef CONFIG_IPV6_MIP6 |
272 | { | |
273 | .type = IPV6_TLV_HAO, | |
274 | .func = ipv6_dest_hao, | |
275 | }, | |
276 | #endif | |
1da177e4 LT |
277 | {-1, NULL} |
278 | }; | |
279 | ||
951dbc8a | 280 | static int ipv6_destopt_rcv(struct sk_buff **skbp) |
1da177e4 LT |
281 | { |
282 | struct sk_buff *skb = *skbp; | |
283 | struct inet6_skb_parm *opt = IP6CB(skb); | |
a831f5bb MN |
284 | #ifdef CONFIG_IPV6_MIP6 |
285 | __u16 dstbuf; | |
286 | #endif | |
1da177e4 LT |
287 | |
288 | if (!pskb_may_pull(skb, (skb->h.raw-skb->data)+8) || | |
289 | !pskb_may_pull(skb, (skb->h.raw-skb->data)+((skb->h.raw[1]+1)<<3))) { | |
290 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); | |
291 | kfree_skb(skb); | |
292 | return -1; | |
293 | } | |
294 | ||
333fad53 | 295 | opt->lastopt = skb->h.raw - skb->nh.raw; |
1da177e4 | 296 | opt->dst1 = skb->h.raw - skb->nh.raw; |
a831f5bb MN |
297 | #ifdef CONFIG_IPV6_MIP6 |
298 | dstbuf = opt->dst1; | |
299 | #endif | |
1da177e4 | 300 | |
a80ff03e MN |
301 | if (ip6_parse_tlv(tlvprocdestopt_lst, skbp)) { |
302 | skb = *skbp; | |
1da177e4 | 303 | skb->h.raw += ((skb->h.raw[1]+1)<<3); |
dc435e6d | 304 | opt = IP6CB(skb); |
a831f5bb MN |
305 | #ifdef CONFIG_IPV6_MIP6 |
306 | opt->nhoff = dstbuf; | |
307 | #else | |
951dbc8a | 308 | opt->nhoff = opt->dst1; |
a831f5bb | 309 | #endif |
1da177e4 LT |
310 | return 1; |
311 | } | |
312 | ||
313 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); | |
314 | return -1; | |
315 | } | |
316 | ||
317 | static struct inet6_protocol destopt_protocol = { | |
318 | .handler = ipv6_destopt_rcv, | |
adcfc7d0 | 319 | .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR, |
1da177e4 LT |
320 | }; |
321 | ||
322 | void __init ipv6_destopt_init(void) | |
323 | { | |
324 | if (inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS) < 0) | |
325 | printk(KERN_ERR "ipv6_destopt_init: Could not register protocol\n"); | |
326 | } | |
327 | ||
328 | /******************************** | |
329 | NONE header. No data in packet. | |
330 | ********************************/ | |
331 | ||
951dbc8a | 332 | static int ipv6_nodata_rcv(struct sk_buff **skbp) |
1da177e4 LT |
333 | { |
334 | struct sk_buff *skb = *skbp; | |
335 | ||
336 | kfree_skb(skb); | |
337 | return 0; | |
338 | } | |
339 | ||
340 | static struct inet6_protocol nodata_protocol = { | |
341 | .handler = ipv6_nodata_rcv, | |
342 | .flags = INET6_PROTO_NOPOLICY, | |
343 | }; | |
344 | ||
345 | void __init ipv6_nodata_init(void) | |
346 | { | |
347 | if (inet6_add_protocol(&nodata_protocol, IPPROTO_NONE) < 0) | |
348 | printk(KERN_ERR "ipv6_nodata_init: Could not register protocol\n"); | |
349 | } | |
350 | ||
351 | /******************************** | |
352 | Routing header. | |
353 | ********************************/ | |
354 | ||
951dbc8a | 355 | static int ipv6_rthdr_rcv(struct sk_buff **skbp) |
1da177e4 LT |
356 | { |
357 | struct sk_buff *skb = *skbp; | |
358 | struct inet6_skb_parm *opt = IP6CB(skb); | |
65d4ed92 | 359 | struct in6_addr *addr = NULL; |
1da177e4 LT |
360 | struct in6_addr daddr; |
361 | int n, i; | |
362 | ||
363 | struct ipv6_rt_hdr *hdr; | |
364 | struct rt0_hdr *rthdr; | |
365 | ||
366 | if (!pskb_may_pull(skb, (skb->h.raw-skb->data)+8) || | |
367 | !pskb_may_pull(skb, (skb->h.raw-skb->data)+((skb->h.raw[1]+1)<<3))) { | |
368 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); | |
369 | kfree_skb(skb); | |
370 | return -1; | |
371 | } | |
372 | ||
373 | hdr = (struct ipv6_rt_hdr *) skb->h.raw; | |
374 | ||
375 | if (ipv6_addr_is_multicast(&skb->nh.ipv6h->daddr) || | |
376 | skb->pkt_type != PACKET_HOST) { | |
377 | IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS); | |
378 | kfree_skb(skb); | |
379 | return -1; | |
380 | } | |
381 | ||
382 | looped_back: | |
383 | if (hdr->segments_left == 0) { | |
65d4ed92 MN |
384 | switch (hdr->type) { |
385 | #ifdef CONFIG_IPV6_MIP6 | |
386 | case IPV6_SRCRT_TYPE_2: | |
387 | /* Silently discard type 2 header unless it was | |
388 | * processed by own | |
389 | */ | |
390 | if (!addr) { | |
391 | IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS); | |
392 | kfree_skb(skb); | |
393 | return -1; | |
394 | } | |
395 | break; | |
396 | #endif | |
397 | default: | |
398 | break; | |
399 | } | |
400 | ||
333fad53 | 401 | opt->lastopt = skb->h.raw - skb->nh.raw; |
1da177e4 LT |
402 | opt->srcrt = skb->h.raw - skb->nh.raw; |
403 | skb->h.raw += (hdr->hdrlen + 1) << 3; | |
404 | opt->dst0 = opt->dst1; | |
405 | opt->dst1 = 0; | |
951dbc8a | 406 | opt->nhoff = (&hdr->nexthdr) - skb->nh.raw; |
1da177e4 LT |
407 | return 1; |
408 | } | |
409 | ||
65d4ed92 MN |
410 | switch (hdr->type) { |
411 | case IPV6_SRCRT_TYPE_0: | |
412 | if (hdr->hdrlen & 0x01) { | |
413 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); | |
414 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, (&hdr->hdrlen) - skb->nh.raw); | |
415 | return -1; | |
416 | } | |
417 | break; | |
418 | #ifdef CONFIG_IPV6_MIP6 | |
419 | case IPV6_SRCRT_TYPE_2: | |
420 | /* Silently discard invalid RTH type 2 */ | |
421 | if (hdr->hdrlen != 2 || hdr->segments_left != 1) { | |
422 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); | |
423 | kfree_skb(skb); | |
424 | return -1; | |
425 | } | |
426 | break; | |
427 | #endif | |
428 | default: | |
1da177e4 LT |
429 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); |
430 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, (&hdr->type) - skb->nh.raw); | |
431 | return -1; | |
432 | } | |
1da177e4 LT |
433 | |
434 | /* | |
435 | * This is the routing header forwarding algorithm from | |
436 | * RFC 2460, page 16. | |
437 | */ | |
438 | ||
439 | n = hdr->hdrlen >> 1; | |
440 | ||
441 | if (hdr->segments_left > n) { | |
442 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); | |
443 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, (&hdr->segments_left) - skb->nh.raw); | |
444 | return -1; | |
445 | } | |
446 | ||
447 | /* We are about to mangle packet header. Be careful! | |
448 | Do not damage packets queued somewhere. | |
449 | */ | |
450 | if (skb_cloned(skb)) { | |
451 | struct sk_buff *skb2 = skb_copy(skb, GFP_ATOMIC); | |
452 | kfree_skb(skb); | |
453 | /* the copy is a forwarded packet */ | |
454 | if (skb2 == NULL) { | |
455 | IP6_INC_STATS_BH(IPSTATS_MIB_OUTDISCARDS); | |
456 | return -1; | |
457 | } | |
458 | *skbp = skb = skb2; | |
459 | opt = IP6CB(skb2); | |
460 | hdr = (struct ipv6_rt_hdr *) skb2->h.raw; | |
461 | } | |
462 | ||
84fa7933 | 463 | if (skb->ip_summed == CHECKSUM_COMPLETE) |
1da177e4 LT |
464 | skb->ip_summed = CHECKSUM_NONE; |
465 | ||
466 | i = n - --hdr->segments_left; | |
467 | ||
468 | rthdr = (struct rt0_hdr *) hdr; | |
469 | addr = rthdr->addr; | |
470 | addr += i - 1; | |
471 | ||
65d4ed92 MN |
472 | switch (hdr->type) { |
473 | #ifdef CONFIG_IPV6_MIP6 | |
474 | case IPV6_SRCRT_TYPE_2: | |
475 | if (xfrm6_input_addr(skb, (xfrm_address_t *)addr, | |
476 | (xfrm_address_t *)&skb->nh.ipv6h->saddr, | |
477 | IPPROTO_ROUTING) < 0) { | |
478 | IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS); | |
479 | kfree_skb(skb); | |
480 | return -1; | |
481 | } | |
482 | if (!ipv6_chk_home_addr(addr)) { | |
483 | IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS); | |
484 | kfree_skb(skb); | |
485 | return -1; | |
486 | } | |
487 | break; | |
488 | #endif | |
489 | default: | |
490 | break; | |
491 | } | |
492 | ||
1da177e4 LT |
493 | if (ipv6_addr_is_multicast(addr)) { |
494 | IP6_INC_STATS_BH(IPSTATS_MIB_INADDRERRORS); | |
495 | kfree_skb(skb); | |
496 | return -1; | |
497 | } | |
498 | ||
499 | ipv6_addr_copy(&daddr, addr); | |
500 | ipv6_addr_copy(addr, &skb->nh.ipv6h->daddr); | |
501 | ipv6_addr_copy(&skb->nh.ipv6h->daddr, &daddr); | |
502 | ||
503 | dst_release(xchg(&skb->dst, NULL)); | |
504 | ip6_route_input(skb); | |
505 | if (skb->dst->error) { | |
506 | skb_push(skb, skb->data - skb->nh.raw); | |
507 | dst_input(skb); | |
508 | return -1; | |
509 | } | |
510 | ||
511 | if (skb->dst->dev->flags&IFF_LOOPBACK) { | |
512 | if (skb->nh.ipv6h->hop_limit <= 1) { | |
513 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); | |
514 | icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, | |
515 | 0, skb->dev); | |
516 | kfree_skb(skb); | |
517 | return -1; | |
518 | } | |
519 | skb->nh.ipv6h->hop_limit--; | |
520 | goto looped_back; | |
521 | } | |
522 | ||
523 | skb_push(skb, skb->data - skb->nh.raw); | |
524 | dst_input(skb); | |
525 | return -1; | |
526 | } | |
527 | ||
528 | static struct inet6_protocol rthdr_protocol = { | |
529 | .handler = ipv6_rthdr_rcv, | |
adcfc7d0 | 530 | .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR, |
1da177e4 LT |
531 | }; |
532 | ||
533 | void __init ipv6_rthdr_init(void) | |
534 | { | |
535 | if (inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING) < 0) | |
536 | printk(KERN_ERR "ipv6_rthdr_init: Could not register protocol\n"); | |
537 | }; | |
538 | ||
539 | /* | |
540 | This function inverts received rthdr. | |
541 | NOTE: specs allow to make it automatically only if | |
542 | packet authenticated. | |
543 | ||
544 | I will not discuss it here (though, I am really pissed off at | |
545 | this stupid requirement making rthdr idea useless) | |
546 | ||
547 | Actually, it creates severe problems for us. | |
548 | Embryonic requests has no associated sockets, | |
549 | so that user have no control over it and | |
550 | cannot not only to set reply options, but | |
551 | even to know, that someone wants to connect | |
552 | without success. :-( | |
553 | ||
554 | For now we need to test the engine, so that I created | |
555 | temporary (or permanent) backdoor. | |
556 | If listening socket set IPV6_RTHDR to 2, then we invert header. | |
557 | --ANK (980729) | |
558 | */ | |
559 | ||
560 | struct ipv6_txoptions * | |
561 | ipv6_invert_rthdr(struct sock *sk, struct ipv6_rt_hdr *hdr) | |
562 | { | |
563 | /* Received rthdr: | |
564 | ||
565 | [ H1 -> H2 -> ... H_prev ] daddr=ME | |
566 | ||
567 | Inverted result: | |
568 | [ H_prev -> ... -> H1 ] daddr =sender | |
569 | ||
570 | Note, that IP output engine will rewrite this rthdr | |
571 | by rotating it left by one addr. | |
572 | */ | |
573 | ||
574 | int n, i; | |
575 | struct rt0_hdr *rthdr = (struct rt0_hdr*)hdr; | |
576 | struct rt0_hdr *irthdr; | |
577 | struct ipv6_txoptions *opt; | |
578 | int hdrlen = ipv6_optlen(hdr); | |
579 | ||
580 | if (hdr->segments_left || | |
581 | hdr->type != IPV6_SRCRT_TYPE_0 || | |
582 | hdr->hdrlen & 0x01) | |
583 | return NULL; | |
584 | ||
585 | n = hdr->hdrlen >> 1; | |
586 | opt = sock_kmalloc(sk, sizeof(*opt) + hdrlen, GFP_ATOMIC); | |
587 | if (opt == NULL) | |
588 | return NULL; | |
589 | memset(opt, 0, sizeof(*opt)); | |
590 | opt->tot_len = sizeof(*opt) + hdrlen; | |
591 | opt->srcrt = (void*)(opt+1); | |
592 | opt->opt_nflen = hdrlen; | |
593 | ||
594 | memcpy(opt->srcrt, hdr, sizeof(*hdr)); | |
595 | irthdr = (struct rt0_hdr*)opt->srcrt; | |
e6df439b | 596 | irthdr->reserved = 0; |
1da177e4 LT |
597 | opt->srcrt->segments_left = n; |
598 | for (i=0; i<n; i++) | |
599 | memcpy(irthdr->addr+i, rthdr->addr+(n-1-i), 16); | |
600 | return opt; | |
601 | } | |
602 | ||
3cf3dc6c ACM |
603 | EXPORT_SYMBOL_GPL(ipv6_invert_rthdr); |
604 | ||
1da177e4 LT |
605 | /********************************** |
606 | Hop-by-hop options. | |
607 | **********************************/ | |
608 | ||
609 | /* Router Alert as of RFC 2711 */ | |
610 | ||
a80ff03e | 611 | static int ipv6_hop_ra(struct sk_buff **skbp, int optoff) |
1da177e4 | 612 | { |
a80ff03e MN |
613 | struct sk_buff *skb = *skbp; |
614 | ||
1da177e4 LT |
615 | if (skb->nh.raw[optoff+1] == 2) { |
616 | IP6CB(skb)->ra = optoff; | |
617 | return 1; | |
618 | } | |
64ce2073 PM |
619 | LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_ra: wrong RA length %d\n", |
620 | skb->nh.raw[optoff+1]); | |
1da177e4 LT |
621 | kfree_skb(skb); |
622 | return 0; | |
623 | } | |
624 | ||
625 | /* Jumbo payload */ | |
626 | ||
a80ff03e | 627 | static int ipv6_hop_jumbo(struct sk_buff **skbp, int optoff) |
1da177e4 | 628 | { |
a80ff03e | 629 | struct sk_buff *skb = *skbp; |
1da177e4 LT |
630 | u32 pkt_len; |
631 | ||
632 | if (skb->nh.raw[optoff+1] != 4 || (optoff&3) != 2) { | |
64ce2073 PM |
633 | LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n", |
634 | skb->nh.raw[optoff+1]); | |
1da177e4 LT |
635 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); |
636 | goto drop; | |
637 | } | |
638 | ||
639 | pkt_len = ntohl(*(u32*)(skb->nh.raw+optoff+2)); | |
640 | if (pkt_len <= IPV6_MAXPLEN) { | |
641 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); | |
642 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2); | |
643 | return 0; | |
644 | } | |
645 | if (skb->nh.ipv6h->payload_len) { | |
646 | IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS); | |
647 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff); | |
648 | return 0; | |
649 | } | |
650 | ||
651 | if (pkt_len > skb->len - sizeof(struct ipv6hdr)) { | |
652 | IP6_INC_STATS_BH(IPSTATS_MIB_INTRUNCATEDPKTS); | |
653 | goto drop; | |
654 | } | |
42ca89c1 SH |
655 | |
656 | if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) | |
657 | goto drop; | |
658 | ||
1da177e4 LT |
659 | return 1; |
660 | ||
661 | drop: | |
662 | kfree_skb(skb); | |
663 | return 0; | |
664 | } | |
665 | ||
666 | static struct tlvtype_proc tlvprochopopt_lst[] = { | |
667 | { | |
668 | .type = IPV6_TLV_ROUTERALERT, | |
669 | .func = ipv6_hop_ra, | |
670 | }, | |
671 | { | |
672 | .type = IPV6_TLV_JUMBO, | |
673 | .func = ipv6_hop_jumbo, | |
674 | }, | |
675 | { -1, } | |
676 | }; | |
677 | ||
a80ff03e | 678 | int ipv6_parse_hopopts(struct sk_buff **skbp) |
1da177e4 | 679 | { |
a80ff03e | 680 | struct sk_buff *skb = *skbp; |
951dbc8a PM |
681 | struct inet6_skb_parm *opt = IP6CB(skb); |
682 | ||
ec670095 YH |
683 | /* |
684 | * skb->nh.raw is equal to skb->data, and | |
685 | * skb->h.raw - skb->nh.raw is always equal to | |
686 | * sizeof(struct ipv6hdr) by definition of | |
687 | * hop-by-hop options. | |
688 | */ | |
689 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) || | |
690 | !pskb_may_pull(skb, sizeof(struct ipv6hdr) + ((skb->h.raw[1] + 1) << 3))) { | |
691 | kfree_skb(skb); | |
692 | return -1; | |
693 | } | |
694 | ||
951dbc8a | 695 | opt->hop = sizeof(struct ipv6hdr); |
a80ff03e MN |
696 | if (ip6_parse_tlv(tlvprochopopt_lst, skbp)) { |
697 | skb = *skbp; | |
951dbc8a | 698 | skb->h.raw += (skb->h.raw[1]+1)<<3; |
dc435e6d | 699 | opt = IP6CB(skb); |
951dbc8a | 700 | opt->nhoff = sizeof(struct ipv6hdr); |
b809739a | 701 | return 1; |
951dbc8a | 702 | } |
1da177e4 LT |
703 | return -1; |
704 | } | |
705 | ||
706 | /* | |
707 | * Creating outbound headers. | |
708 | * | |
709 | * "build" functions work when skb is filled from head to tail (datagram) | |
710 | * "push" functions work when headers are added from tail to head (tcp) | |
711 | * | |
712 | * In both cases we assume, that caller reserved enough room | |
713 | * for headers. | |
714 | */ | |
715 | ||
716 | static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto, | |
717 | struct ipv6_rt_hdr *opt, | |
718 | struct in6_addr **addr_p) | |
719 | { | |
720 | struct rt0_hdr *phdr, *ihdr; | |
721 | int hops; | |
722 | ||
723 | ihdr = (struct rt0_hdr *) opt; | |
724 | ||
725 | phdr = (struct rt0_hdr *) skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3); | |
726 | memcpy(phdr, ihdr, sizeof(struct rt0_hdr)); | |
727 | ||
728 | hops = ihdr->rt_hdr.hdrlen >> 1; | |
729 | ||
730 | if (hops > 1) | |
731 | memcpy(phdr->addr, ihdr->addr + 1, | |
732 | (hops - 1) * sizeof(struct in6_addr)); | |
733 | ||
734 | ipv6_addr_copy(phdr->addr + (hops - 1), *addr_p); | |
735 | *addr_p = ihdr->addr; | |
736 | ||
737 | phdr->rt_hdr.nexthdr = *proto; | |
738 | *proto = NEXTHDR_ROUTING; | |
739 | } | |
740 | ||
741 | static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt) | |
742 | { | |
743 | struct ipv6_opt_hdr *h = (struct ipv6_opt_hdr *)skb_push(skb, ipv6_optlen(opt)); | |
744 | ||
745 | memcpy(h, opt, ipv6_optlen(opt)); | |
746 | h->nexthdr = *proto; | |
747 | *proto = type; | |
748 | } | |
749 | ||
750 | void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, | |
751 | u8 *proto, | |
752 | struct in6_addr **daddr) | |
753 | { | |
333fad53 | 754 | if (opt->srcrt) { |
1da177e4 | 755 | ipv6_push_rthdr(skb, proto, opt->srcrt, daddr); |
333fad53 YH |
756 | /* |
757 | * IPV6_RTHDRDSTOPTS is ignored | |
758 | * unless IPV6_RTHDR is set (RFC3542). | |
759 | */ | |
760 | if (opt->dst0opt) | |
761 | ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt); | |
762 | } | |
1da177e4 LT |
763 | if (opt->hopopt) |
764 | ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt); | |
765 | } | |
766 | ||
767 | void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto) | |
768 | { | |
769 | if (opt->dst1opt) | |
770 | ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt); | |
771 | } | |
772 | ||
773 | struct ipv6_txoptions * | |
774 | ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt) | |
775 | { | |
776 | struct ipv6_txoptions *opt2; | |
777 | ||
778 | opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC); | |
779 | if (opt2) { | |
780 | long dif = (char*)opt2 - (char*)opt; | |
781 | memcpy(opt2, opt, opt->tot_len); | |
782 | if (opt2->hopopt) | |
783 | *((char**)&opt2->hopopt) += dif; | |
784 | if (opt2->dst0opt) | |
785 | *((char**)&opt2->dst0opt) += dif; | |
786 | if (opt2->dst1opt) | |
787 | *((char**)&opt2->dst1opt) += dif; | |
788 | if (opt2->srcrt) | |
789 | *((char**)&opt2->srcrt) += dif; | |
790 | } | |
791 | return opt2; | |
792 | } | |
333fad53 | 793 | |
3cf3dc6c ACM |
794 | EXPORT_SYMBOL_GPL(ipv6_dup_options); |
795 | ||
333fad53 YH |
796 | static int ipv6_renew_option(void *ohdr, |
797 | struct ipv6_opt_hdr __user *newopt, int newoptlen, | |
798 | int inherit, | |
799 | struct ipv6_opt_hdr **hdr, | |
800 | char **p) | |
801 | { | |
802 | if (inherit) { | |
803 | if (ohdr) { | |
804 | memcpy(*p, ohdr, ipv6_optlen((struct ipv6_opt_hdr *)ohdr)); | |
805 | *hdr = (struct ipv6_opt_hdr *)*p; | |
806 | *p += CMSG_ALIGN(ipv6_optlen(*(struct ipv6_opt_hdr **)hdr)); | |
807 | } | |
808 | } else { | |
809 | if (newopt) { | |
810 | if (copy_from_user(*p, newopt, newoptlen)) | |
811 | return -EFAULT; | |
812 | *hdr = (struct ipv6_opt_hdr *)*p; | |
813 | if (ipv6_optlen(*(struct ipv6_opt_hdr **)hdr) > newoptlen) | |
814 | return -EINVAL; | |
815 | *p += CMSG_ALIGN(newoptlen); | |
816 | } | |
817 | } | |
818 | return 0; | |
819 | } | |
820 | ||
821 | struct ipv6_txoptions * | |
822 | ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt, | |
823 | int newtype, | |
824 | struct ipv6_opt_hdr __user *newopt, int newoptlen) | |
825 | { | |
826 | int tot_len = 0; | |
827 | char *p; | |
828 | struct ipv6_txoptions *opt2; | |
829 | int err; | |
830 | ||
99c7bc01 YH |
831 | if (opt) { |
832 | if (newtype != IPV6_HOPOPTS && opt->hopopt) | |
833 | tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt)); | |
834 | if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt) | |
835 | tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt)); | |
836 | if (newtype != IPV6_RTHDR && opt->srcrt) | |
837 | tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt)); | |
838 | if (newtype != IPV6_DSTOPTS && opt->dst1opt) | |
839 | tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt)); | |
840 | } | |
841 | ||
333fad53 YH |
842 | if (newopt && newoptlen) |
843 | tot_len += CMSG_ALIGN(newoptlen); | |
844 | ||
845 | if (!tot_len) | |
846 | return NULL; | |
847 | ||
8b8aa4b5 | 848 | tot_len += sizeof(*opt2); |
333fad53 YH |
849 | opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC); |
850 | if (!opt2) | |
851 | return ERR_PTR(-ENOBUFS); | |
852 | ||
853 | memset(opt2, 0, tot_len); | |
854 | ||
855 | opt2->tot_len = tot_len; | |
856 | p = (char *)(opt2 + 1); | |
857 | ||
99c7bc01 | 858 | err = ipv6_renew_option(opt ? opt->hopopt : NULL, newopt, newoptlen, |
333fad53 YH |
859 | newtype != IPV6_HOPOPTS, |
860 | &opt2->hopopt, &p); | |
861 | if (err) | |
862 | goto out; | |
863 | ||
99c7bc01 | 864 | err = ipv6_renew_option(opt ? opt->dst0opt : NULL, newopt, newoptlen, |
333fad53 YH |
865 | newtype != IPV6_RTHDRDSTOPTS, |
866 | &opt2->dst0opt, &p); | |
867 | if (err) | |
868 | goto out; | |
869 | ||
99c7bc01 | 870 | err = ipv6_renew_option(opt ? opt->srcrt : NULL, newopt, newoptlen, |
333fad53 | 871 | newtype != IPV6_RTHDR, |
99c7bc01 | 872 | (struct ipv6_opt_hdr **)&opt2->srcrt, &p); |
333fad53 YH |
873 | if (err) |
874 | goto out; | |
875 | ||
99c7bc01 | 876 | err = ipv6_renew_option(opt ? opt->dst1opt : NULL, newopt, newoptlen, |
333fad53 YH |
877 | newtype != IPV6_DSTOPTS, |
878 | &opt2->dst1opt, &p); | |
879 | if (err) | |
880 | goto out; | |
881 | ||
882 | opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) + | |
883 | (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) + | |
884 | (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0); | |
885 | opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0); | |
886 | ||
887 | return opt2; | |
888 | out: | |
8b8aa4b5 | 889 | sock_kfree_s(sk, opt2, opt2->tot_len); |
333fad53 YH |
890 | return ERR_PTR(err); |
891 | } | |
892 | ||
df9890c3 YH |
893 | struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space, |
894 | struct ipv6_txoptions *opt) | |
895 | { | |
896 | /* | |
897 | * ignore the dest before srcrt unless srcrt is being included. | |
898 | * --yoshfuji | |
899 | */ | |
900 | if (opt && opt->dst0opt && !opt->srcrt) { | |
901 | if (opt_space != opt) { | |
902 | memcpy(opt_space, opt, sizeof(*opt_space)); | |
903 | opt = opt_space; | |
904 | } | |
905 | opt->opt_nflen -= ipv6_optlen(opt->dst0opt); | |
906 | opt->dst0opt = NULL; | |
907 | } | |
908 | ||
909 | return opt; | |
910 | } | |
911 |