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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); | |
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 | |
a11d206d | 287 | struct dst_entry *dst; |
1da177e4 LT |
288 | |
289 | if (!pskb_may_pull(skb, (skb->h.raw-skb->data)+8) || | |
290 | !pskb_may_pull(skb, (skb->h.raw-skb->data)+((skb->h.raw[1]+1)<<3))) { | |
a11d206d YH |
291 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), |
292 | IPSTATS_MIB_INHDRERRORS); | |
1da177e4 LT |
293 | kfree_skb(skb); |
294 | return -1; | |
295 | } | |
296 | ||
333fad53 | 297 | opt->lastopt = skb->h.raw - skb->nh.raw; |
1da177e4 | 298 | opt->dst1 = skb->h.raw - skb->nh.raw; |
a831f5bb MN |
299 | #ifdef CONFIG_IPV6_MIP6 |
300 | dstbuf = opt->dst1; | |
301 | #endif | |
1da177e4 | 302 | |
a11d206d | 303 | dst = dst_clone(skb->dst); |
a80ff03e | 304 | if (ip6_parse_tlv(tlvprocdestopt_lst, skbp)) { |
a11d206d | 305 | dst_release(dst); |
a80ff03e | 306 | skb = *skbp; |
1da177e4 | 307 | skb->h.raw += ((skb->h.raw[1]+1)<<3); |
dc435e6d | 308 | opt = IP6CB(skb); |
a831f5bb MN |
309 | #ifdef CONFIG_IPV6_MIP6 |
310 | opt->nhoff = dstbuf; | |
311 | #else | |
951dbc8a | 312 | opt->nhoff = opt->dst1; |
a831f5bb | 313 | #endif |
1da177e4 LT |
314 | return 1; |
315 | } | |
316 | ||
a11d206d YH |
317 | IP6_INC_STATS_BH(ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS); |
318 | dst_release(dst); | |
1da177e4 LT |
319 | return -1; |
320 | } | |
321 | ||
322 | static struct inet6_protocol destopt_protocol = { | |
323 | .handler = ipv6_destopt_rcv, | |
adcfc7d0 | 324 | .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR, |
1da177e4 LT |
325 | }; |
326 | ||
327 | void __init ipv6_destopt_init(void) | |
328 | { | |
329 | if (inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS) < 0) | |
330 | printk(KERN_ERR "ipv6_destopt_init: Could not register protocol\n"); | |
331 | } | |
332 | ||
333 | /******************************** | |
334 | NONE header. No data in packet. | |
335 | ********************************/ | |
336 | ||
951dbc8a | 337 | static int ipv6_nodata_rcv(struct sk_buff **skbp) |
1da177e4 LT |
338 | { |
339 | struct sk_buff *skb = *skbp; | |
340 | ||
341 | kfree_skb(skb); | |
342 | return 0; | |
343 | } | |
344 | ||
345 | static struct inet6_protocol nodata_protocol = { | |
346 | .handler = ipv6_nodata_rcv, | |
347 | .flags = INET6_PROTO_NOPOLICY, | |
348 | }; | |
349 | ||
350 | void __init ipv6_nodata_init(void) | |
351 | { | |
352 | if (inet6_add_protocol(&nodata_protocol, IPPROTO_NONE) < 0) | |
353 | printk(KERN_ERR "ipv6_nodata_init: Could not register protocol\n"); | |
354 | } | |
355 | ||
356 | /******************************** | |
357 | Routing header. | |
358 | ********************************/ | |
359 | ||
951dbc8a | 360 | static int ipv6_rthdr_rcv(struct sk_buff **skbp) |
1da177e4 LT |
361 | { |
362 | struct sk_buff *skb = *skbp; | |
363 | struct inet6_skb_parm *opt = IP6CB(skb); | |
65d4ed92 | 364 | struct in6_addr *addr = NULL; |
1da177e4 LT |
365 | struct in6_addr daddr; |
366 | int n, i; | |
367 | ||
368 | struct ipv6_rt_hdr *hdr; | |
369 | struct rt0_hdr *rthdr; | |
370 | ||
371 | if (!pskb_may_pull(skb, (skb->h.raw-skb->data)+8) || | |
372 | !pskb_may_pull(skb, (skb->h.raw-skb->data)+((skb->h.raw[1]+1)<<3))) { | |
a11d206d YH |
373 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), |
374 | IPSTATS_MIB_INHDRERRORS); | |
1da177e4 LT |
375 | kfree_skb(skb); |
376 | return -1; | |
377 | } | |
378 | ||
379 | hdr = (struct ipv6_rt_hdr *) skb->h.raw; | |
380 | ||
381 | if (ipv6_addr_is_multicast(&skb->nh.ipv6h->daddr) || | |
382 | skb->pkt_type != PACKET_HOST) { | |
a11d206d YH |
383 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), |
384 | IPSTATS_MIB_INADDRERRORS); | |
1da177e4 LT |
385 | kfree_skb(skb); |
386 | return -1; | |
387 | } | |
388 | ||
389 | looped_back: | |
390 | if (hdr->segments_left == 0) { | |
65d4ed92 MN |
391 | switch (hdr->type) { |
392 | #ifdef CONFIG_IPV6_MIP6 | |
393 | case IPV6_SRCRT_TYPE_2: | |
394 | /* Silently discard type 2 header unless it was | |
395 | * processed by own | |
396 | */ | |
397 | if (!addr) { | |
a11d206d YH |
398 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), |
399 | IPSTATS_MIB_INADDRERRORS); | |
65d4ed92 MN |
400 | kfree_skb(skb); |
401 | return -1; | |
402 | } | |
403 | break; | |
404 | #endif | |
405 | default: | |
406 | break; | |
407 | } | |
408 | ||
333fad53 | 409 | opt->lastopt = skb->h.raw - skb->nh.raw; |
1da177e4 LT |
410 | opt->srcrt = skb->h.raw - skb->nh.raw; |
411 | skb->h.raw += (hdr->hdrlen + 1) << 3; | |
412 | opt->dst0 = opt->dst1; | |
413 | opt->dst1 = 0; | |
951dbc8a | 414 | opt->nhoff = (&hdr->nexthdr) - skb->nh.raw; |
1da177e4 LT |
415 | return 1; |
416 | } | |
417 | ||
65d4ed92 MN |
418 | switch (hdr->type) { |
419 | case IPV6_SRCRT_TYPE_0: | |
420 | if (hdr->hdrlen & 0x01) { | |
a11d206d YH |
421 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), |
422 | IPSTATS_MIB_INHDRERRORS); | |
65d4ed92 MN |
423 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, (&hdr->hdrlen) - skb->nh.raw); |
424 | return -1; | |
425 | } | |
426 | break; | |
427 | #ifdef CONFIG_IPV6_MIP6 | |
428 | case IPV6_SRCRT_TYPE_2: | |
429 | /* Silently discard invalid RTH type 2 */ | |
430 | if (hdr->hdrlen != 2 || hdr->segments_left != 1) { | |
a11d206d YH |
431 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), |
432 | IPSTATS_MIB_INHDRERRORS); | |
65d4ed92 MN |
433 | kfree_skb(skb); |
434 | return -1; | |
435 | } | |
436 | break; | |
437 | #endif | |
438 | default: | |
a11d206d YH |
439 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), |
440 | IPSTATS_MIB_INHDRERRORS); | |
1da177e4 LT |
441 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, (&hdr->type) - skb->nh.raw); |
442 | return -1; | |
443 | } | |
1da177e4 LT |
444 | |
445 | /* | |
446 | * This is the routing header forwarding algorithm from | |
447 | * RFC 2460, page 16. | |
448 | */ | |
449 | ||
450 | n = hdr->hdrlen >> 1; | |
451 | ||
452 | if (hdr->segments_left > n) { | |
a11d206d YH |
453 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), |
454 | IPSTATS_MIB_INHDRERRORS); | |
1da177e4 LT |
455 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, (&hdr->segments_left) - skb->nh.raw); |
456 | return -1; | |
457 | } | |
458 | ||
459 | /* We are about to mangle packet header. Be careful! | |
460 | Do not damage packets queued somewhere. | |
461 | */ | |
462 | if (skb_cloned(skb)) { | |
463 | struct sk_buff *skb2 = skb_copy(skb, GFP_ATOMIC); | |
1da177e4 LT |
464 | /* the copy is a forwarded packet */ |
465 | if (skb2 == NULL) { | |
a11d206d YH |
466 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), |
467 | IPSTATS_MIB_OUTDISCARDS); | |
468 | kfree_skb(skb); | |
1da177e4 LT |
469 | return -1; |
470 | } | |
a11d206d | 471 | kfree_skb(skb); |
1da177e4 LT |
472 | *skbp = skb = skb2; |
473 | opt = IP6CB(skb2); | |
474 | hdr = (struct ipv6_rt_hdr *) skb2->h.raw; | |
475 | } | |
476 | ||
84fa7933 | 477 | if (skb->ip_summed == CHECKSUM_COMPLETE) |
1da177e4 LT |
478 | skb->ip_summed = CHECKSUM_NONE; |
479 | ||
480 | i = n - --hdr->segments_left; | |
481 | ||
482 | rthdr = (struct rt0_hdr *) hdr; | |
483 | addr = rthdr->addr; | |
484 | addr += i - 1; | |
485 | ||
65d4ed92 MN |
486 | switch (hdr->type) { |
487 | #ifdef CONFIG_IPV6_MIP6 | |
488 | case IPV6_SRCRT_TYPE_2: | |
489 | if (xfrm6_input_addr(skb, (xfrm_address_t *)addr, | |
490 | (xfrm_address_t *)&skb->nh.ipv6h->saddr, | |
491 | IPPROTO_ROUTING) < 0) { | |
a11d206d YH |
492 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), |
493 | IPSTATS_MIB_INADDRERRORS); | |
65d4ed92 MN |
494 | kfree_skb(skb); |
495 | return -1; | |
496 | } | |
497 | if (!ipv6_chk_home_addr(addr)) { | |
a11d206d YH |
498 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), |
499 | IPSTATS_MIB_INADDRERRORS); | |
65d4ed92 MN |
500 | kfree_skb(skb); |
501 | return -1; | |
502 | } | |
503 | break; | |
504 | #endif | |
505 | default: | |
506 | break; | |
507 | } | |
508 | ||
1da177e4 | 509 | if (ipv6_addr_is_multicast(addr)) { |
a11d206d YH |
510 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), |
511 | IPSTATS_MIB_INADDRERRORS); | |
1da177e4 LT |
512 | kfree_skb(skb); |
513 | return -1; | |
514 | } | |
515 | ||
516 | ipv6_addr_copy(&daddr, addr); | |
517 | ipv6_addr_copy(addr, &skb->nh.ipv6h->daddr); | |
518 | ipv6_addr_copy(&skb->nh.ipv6h->daddr, &daddr); | |
519 | ||
520 | dst_release(xchg(&skb->dst, NULL)); | |
521 | ip6_route_input(skb); | |
522 | if (skb->dst->error) { | |
523 | skb_push(skb, skb->data - skb->nh.raw); | |
524 | dst_input(skb); | |
525 | return -1; | |
526 | } | |
527 | ||
528 | if (skb->dst->dev->flags&IFF_LOOPBACK) { | |
529 | if (skb->nh.ipv6h->hop_limit <= 1) { | |
a11d206d YH |
530 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), |
531 | IPSTATS_MIB_INHDRERRORS); | |
1da177e4 LT |
532 | icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, |
533 | 0, skb->dev); | |
534 | kfree_skb(skb); | |
535 | return -1; | |
536 | } | |
537 | skb->nh.ipv6h->hop_limit--; | |
538 | goto looped_back; | |
539 | } | |
540 | ||
541 | skb_push(skb, skb->data - skb->nh.raw); | |
542 | dst_input(skb); | |
543 | return -1; | |
544 | } | |
545 | ||
546 | static struct inet6_protocol rthdr_protocol = { | |
547 | .handler = ipv6_rthdr_rcv, | |
adcfc7d0 | 548 | .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR, |
1da177e4 LT |
549 | }; |
550 | ||
551 | void __init ipv6_rthdr_init(void) | |
552 | { | |
553 | if (inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING) < 0) | |
554 | printk(KERN_ERR "ipv6_rthdr_init: Could not register protocol\n"); | |
555 | }; | |
556 | ||
557 | /* | |
558 | This function inverts received rthdr. | |
559 | NOTE: specs allow to make it automatically only if | |
560 | packet authenticated. | |
561 | ||
562 | I will not discuss it here (though, I am really pissed off at | |
563 | this stupid requirement making rthdr idea useless) | |
564 | ||
565 | Actually, it creates severe problems for us. | |
566 | Embryonic requests has no associated sockets, | |
567 | so that user have no control over it and | |
568 | cannot not only to set reply options, but | |
569 | even to know, that someone wants to connect | |
570 | without success. :-( | |
571 | ||
572 | For now we need to test the engine, so that I created | |
573 | temporary (or permanent) backdoor. | |
574 | If listening socket set IPV6_RTHDR to 2, then we invert header. | |
575 | --ANK (980729) | |
576 | */ | |
577 | ||
578 | struct ipv6_txoptions * | |
579 | ipv6_invert_rthdr(struct sock *sk, struct ipv6_rt_hdr *hdr) | |
580 | { | |
581 | /* Received rthdr: | |
582 | ||
583 | [ H1 -> H2 -> ... H_prev ] daddr=ME | |
584 | ||
585 | Inverted result: | |
586 | [ H_prev -> ... -> H1 ] daddr =sender | |
587 | ||
588 | Note, that IP output engine will rewrite this rthdr | |
589 | by rotating it left by one addr. | |
590 | */ | |
591 | ||
592 | int n, i; | |
593 | struct rt0_hdr *rthdr = (struct rt0_hdr*)hdr; | |
594 | struct rt0_hdr *irthdr; | |
595 | struct ipv6_txoptions *opt; | |
596 | int hdrlen = ipv6_optlen(hdr); | |
597 | ||
598 | if (hdr->segments_left || | |
599 | hdr->type != IPV6_SRCRT_TYPE_0 || | |
600 | hdr->hdrlen & 0x01) | |
601 | return NULL; | |
602 | ||
603 | n = hdr->hdrlen >> 1; | |
604 | opt = sock_kmalloc(sk, sizeof(*opt) + hdrlen, GFP_ATOMIC); | |
605 | if (opt == NULL) | |
606 | return NULL; | |
607 | memset(opt, 0, sizeof(*opt)); | |
608 | opt->tot_len = sizeof(*opt) + hdrlen; | |
609 | opt->srcrt = (void*)(opt+1); | |
610 | opt->opt_nflen = hdrlen; | |
611 | ||
612 | memcpy(opt->srcrt, hdr, sizeof(*hdr)); | |
613 | irthdr = (struct rt0_hdr*)opt->srcrt; | |
e6df439b | 614 | irthdr->reserved = 0; |
1da177e4 LT |
615 | opt->srcrt->segments_left = n; |
616 | for (i=0; i<n; i++) | |
617 | memcpy(irthdr->addr+i, rthdr->addr+(n-1-i), 16); | |
618 | return opt; | |
619 | } | |
620 | ||
3cf3dc6c ACM |
621 | EXPORT_SYMBOL_GPL(ipv6_invert_rthdr); |
622 | ||
1da177e4 LT |
623 | /********************************** |
624 | Hop-by-hop options. | |
625 | **********************************/ | |
626 | ||
627 | /* Router Alert as of RFC 2711 */ | |
628 | ||
a80ff03e | 629 | static int ipv6_hop_ra(struct sk_buff **skbp, int optoff) |
1da177e4 | 630 | { |
a80ff03e MN |
631 | struct sk_buff *skb = *skbp; |
632 | ||
1da177e4 LT |
633 | if (skb->nh.raw[optoff+1] == 2) { |
634 | IP6CB(skb)->ra = optoff; | |
635 | return 1; | |
636 | } | |
64ce2073 PM |
637 | LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_ra: wrong RA length %d\n", |
638 | skb->nh.raw[optoff+1]); | |
1da177e4 LT |
639 | kfree_skb(skb); |
640 | return 0; | |
641 | } | |
642 | ||
643 | /* Jumbo payload */ | |
644 | ||
a80ff03e | 645 | static int ipv6_hop_jumbo(struct sk_buff **skbp, int optoff) |
1da177e4 | 646 | { |
a80ff03e | 647 | struct sk_buff *skb = *skbp; |
1da177e4 LT |
648 | u32 pkt_len; |
649 | ||
650 | if (skb->nh.raw[optoff+1] != 4 || (optoff&3) != 2) { | |
64ce2073 PM |
651 | LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n", |
652 | skb->nh.raw[optoff+1]); | |
a11d206d YH |
653 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), |
654 | IPSTATS_MIB_INHDRERRORS); | |
1da177e4 LT |
655 | goto drop; |
656 | } | |
657 | ||
e69a4adc | 658 | pkt_len = ntohl(*(__be32*)(skb->nh.raw+optoff+2)); |
1da177e4 | 659 | if (pkt_len <= IPV6_MAXPLEN) { |
a11d206d | 660 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS); |
1da177e4 LT |
661 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2); |
662 | return 0; | |
663 | } | |
664 | if (skb->nh.ipv6h->payload_len) { | |
a11d206d | 665 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS); |
1da177e4 LT |
666 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff); |
667 | return 0; | |
668 | } | |
669 | ||
670 | if (pkt_len > skb->len - sizeof(struct ipv6hdr)) { | |
a11d206d | 671 | IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_INTRUNCATEDPKTS); |
1da177e4 LT |
672 | goto drop; |
673 | } | |
42ca89c1 SH |
674 | |
675 | if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) | |
676 | goto drop; | |
677 | ||
1da177e4 LT |
678 | return 1; |
679 | ||
680 | drop: | |
681 | kfree_skb(skb); | |
682 | return 0; | |
683 | } | |
684 | ||
685 | static struct tlvtype_proc tlvprochopopt_lst[] = { | |
686 | { | |
687 | .type = IPV6_TLV_ROUTERALERT, | |
688 | .func = ipv6_hop_ra, | |
689 | }, | |
690 | { | |
691 | .type = IPV6_TLV_JUMBO, | |
692 | .func = ipv6_hop_jumbo, | |
693 | }, | |
694 | { -1, } | |
695 | }; | |
696 | ||
a80ff03e | 697 | int ipv6_parse_hopopts(struct sk_buff **skbp) |
1da177e4 | 698 | { |
a80ff03e | 699 | struct sk_buff *skb = *skbp; |
951dbc8a PM |
700 | struct inet6_skb_parm *opt = IP6CB(skb); |
701 | ||
ec670095 YH |
702 | /* |
703 | * skb->nh.raw is equal to skb->data, and | |
704 | * skb->h.raw - skb->nh.raw is always equal to | |
705 | * sizeof(struct ipv6hdr) by definition of | |
706 | * hop-by-hop options. | |
707 | */ | |
708 | if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) || | |
709 | !pskb_may_pull(skb, sizeof(struct ipv6hdr) + ((skb->h.raw[1] + 1) << 3))) { | |
710 | kfree_skb(skb); | |
711 | return -1; | |
712 | } | |
713 | ||
951dbc8a | 714 | opt->hop = sizeof(struct ipv6hdr); |
a80ff03e MN |
715 | if (ip6_parse_tlv(tlvprochopopt_lst, skbp)) { |
716 | skb = *skbp; | |
951dbc8a | 717 | skb->h.raw += (skb->h.raw[1]+1)<<3; |
dc435e6d | 718 | opt = IP6CB(skb); |
951dbc8a | 719 | opt->nhoff = sizeof(struct ipv6hdr); |
b809739a | 720 | return 1; |
951dbc8a | 721 | } |
1da177e4 LT |
722 | return -1; |
723 | } | |
724 | ||
725 | /* | |
726 | * Creating outbound headers. | |
727 | * | |
728 | * "build" functions work when skb is filled from head to tail (datagram) | |
729 | * "push" functions work when headers are added from tail to head (tcp) | |
730 | * | |
731 | * In both cases we assume, that caller reserved enough room | |
732 | * for headers. | |
733 | */ | |
734 | ||
735 | static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto, | |
736 | struct ipv6_rt_hdr *opt, | |
737 | struct in6_addr **addr_p) | |
738 | { | |
739 | struct rt0_hdr *phdr, *ihdr; | |
740 | int hops; | |
741 | ||
742 | ihdr = (struct rt0_hdr *) opt; | |
743 | ||
744 | phdr = (struct rt0_hdr *) skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3); | |
745 | memcpy(phdr, ihdr, sizeof(struct rt0_hdr)); | |
746 | ||
747 | hops = ihdr->rt_hdr.hdrlen >> 1; | |
748 | ||
749 | if (hops > 1) | |
750 | memcpy(phdr->addr, ihdr->addr + 1, | |
751 | (hops - 1) * sizeof(struct in6_addr)); | |
752 | ||
753 | ipv6_addr_copy(phdr->addr + (hops - 1), *addr_p); | |
754 | *addr_p = ihdr->addr; | |
755 | ||
756 | phdr->rt_hdr.nexthdr = *proto; | |
757 | *proto = NEXTHDR_ROUTING; | |
758 | } | |
759 | ||
760 | static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt) | |
761 | { | |
762 | struct ipv6_opt_hdr *h = (struct ipv6_opt_hdr *)skb_push(skb, ipv6_optlen(opt)); | |
763 | ||
764 | memcpy(h, opt, ipv6_optlen(opt)); | |
765 | h->nexthdr = *proto; | |
766 | *proto = type; | |
767 | } | |
768 | ||
769 | void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, | |
770 | u8 *proto, | |
771 | struct in6_addr **daddr) | |
772 | { | |
333fad53 | 773 | if (opt->srcrt) { |
1da177e4 | 774 | ipv6_push_rthdr(skb, proto, opt->srcrt, daddr); |
333fad53 YH |
775 | /* |
776 | * IPV6_RTHDRDSTOPTS is ignored | |
777 | * unless IPV6_RTHDR is set (RFC3542). | |
778 | */ | |
779 | if (opt->dst0opt) | |
780 | ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt); | |
781 | } | |
1da177e4 LT |
782 | if (opt->hopopt) |
783 | ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt); | |
784 | } | |
785 | ||
786 | void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto) | |
787 | { | |
788 | if (opt->dst1opt) | |
789 | ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt); | |
790 | } | |
791 | ||
792 | struct ipv6_txoptions * | |
793 | ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt) | |
794 | { | |
795 | struct ipv6_txoptions *opt2; | |
796 | ||
797 | opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC); | |
798 | if (opt2) { | |
799 | long dif = (char*)opt2 - (char*)opt; | |
800 | memcpy(opt2, opt, opt->tot_len); | |
801 | if (opt2->hopopt) | |
802 | *((char**)&opt2->hopopt) += dif; | |
803 | if (opt2->dst0opt) | |
804 | *((char**)&opt2->dst0opt) += dif; | |
805 | if (opt2->dst1opt) | |
806 | *((char**)&opt2->dst1opt) += dif; | |
807 | if (opt2->srcrt) | |
808 | *((char**)&opt2->srcrt) += dif; | |
809 | } | |
810 | return opt2; | |
811 | } | |
333fad53 | 812 | |
3cf3dc6c ACM |
813 | EXPORT_SYMBOL_GPL(ipv6_dup_options); |
814 | ||
333fad53 YH |
815 | static int ipv6_renew_option(void *ohdr, |
816 | struct ipv6_opt_hdr __user *newopt, int newoptlen, | |
817 | int inherit, | |
818 | struct ipv6_opt_hdr **hdr, | |
819 | char **p) | |
820 | { | |
821 | if (inherit) { | |
822 | if (ohdr) { | |
823 | memcpy(*p, ohdr, ipv6_optlen((struct ipv6_opt_hdr *)ohdr)); | |
824 | *hdr = (struct ipv6_opt_hdr *)*p; | |
825 | *p += CMSG_ALIGN(ipv6_optlen(*(struct ipv6_opt_hdr **)hdr)); | |
826 | } | |
827 | } else { | |
828 | if (newopt) { | |
829 | if (copy_from_user(*p, newopt, newoptlen)) | |
830 | return -EFAULT; | |
831 | *hdr = (struct ipv6_opt_hdr *)*p; | |
832 | if (ipv6_optlen(*(struct ipv6_opt_hdr **)hdr) > newoptlen) | |
833 | return -EINVAL; | |
834 | *p += CMSG_ALIGN(newoptlen); | |
835 | } | |
836 | } | |
837 | return 0; | |
838 | } | |
839 | ||
840 | struct ipv6_txoptions * | |
841 | ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt, | |
842 | int newtype, | |
843 | struct ipv6_opt_hdr __user *newopt, int newoptlen) | |
844 | { | |
845 | int tot_len = 0; | |
846 | char *p; | |
847 | struct ipv6_txoptions *opt2; | |
848 | int err; | |
849 | ||
99c7bc01 YH |
850 | if (opt) { |
851 | if (newtype != IPV6_HOPOPTS && opt->hopopt) | |
852 | tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt)); | |
853 | if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt) | |
854 | tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt)); | |
855 | if (newtype != IPV6_RTHDR && opt->srcrt) | |
856 | tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt)); | |
857 | if (newtype != IPV6_DSTOPTS && opt->dst1opt) | |
858 | tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt)); | |
859 | } | |
860 | ||
333fad53 YH |
861 | if (newopt && newoptlen) |
862 | tot_len += CMSG_ALIGN(newoptlen); | |
863 | ||
864 | if (!tot_len) | |
865 | return NULL; | |
866 | ||
8b8aa4b5 | 867 | tot_len += sizeof(*opt2); |
333fad53 YH |
868 | opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC); |
869 | if (!opt2) | |
870 | return ERR_PTR(-ENOBUFS); | |
871 | ||
872 | memset(opt2, 0, tot_len); | |
873 | ||
874 | opt2->tot_len = tot_len; | |
875 | p = (char *)(opt2 + 1); | |
876 | ||
99c7bc01 | 877 | err = ipv6_renew_option(opt ? opt->hopopt : NULL, newopt, newoptlen, |
333fad53 YH |
878 | newtype != IPV6_HOPOPTS, |
879 | &opt2->hopopt, &p); | |
880 | if (err) | |
881 | goto out; | |
882 | ||
99c7bc01 | 883 | err = ipv6_renew_option(opt ? opt->dst0opt : NULL, newopt, newoptlen, |
333fad53 YH |
884 | newtype != IPV6_RTHDRDSTOPTS, |
885 | &opt2->dst0opt, &p); | |
886 | if (err) | |
887 | goto out; | |
888 | ||
99c7bc01 | 889 | err = ipv6_renew_option(opt ? opt->srcrt : NULL, newopt, newoptlen, |
333fad53 | 890 | newtype != IPV6_RTHDR, |
99c7bc01 | 891 | (struct ipv6_opt_hdr **)&opt2->srcrt, &p); |
333fad53 YH |
892 | if (err) |
893 | goto out; | |
894 | ||
99c7bc01 | 895 | err = ipv6_renew_option(opt ? opt->dst1opt : NULL, newopt, newoptlen, |
333fad53 YH |
896 | newtype != IPV6_DSTOPTS, |
897 | &opt2->dst1opt, &p); | |
898 | if (err) | |
899 | goto out; | |
900 | ||
901 | opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) + | |
902 | (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) + | |
903 | (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0); | |
904 | opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0); | |
905 | ||
906 | return opt2; | |
907 | out: | |
8b8aa4b5 | 908 | sock_kfree_s(sk, opt2, opt2->tot_len); |
333fad53 YH |
909 | return ERR_PTR(err); |
910 | } | |
911 | ||
df9890c3 YH |
912 | struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space, |
913 | struct ipv6_txoptions *opt) | |
914 | { | |
915 | /* | |
916 | * ignore the dest before srcrt unless srcrt is being included. | |
917 | * --yoshfuji | |
918 | */ | |
919 | if (opt && opt->dst0opt && !opt->srcrt) { | |
920 | if (opt_space != opt) { | |
921 | memcpy(opt_space, opt, sizeof(*opt_space)); | |
922 | opt = opt_space; | |
923 | } | |
924 | opt->opt_nflen -= ipv6_optlen(opt->dst0opt); | |
925 | opt->dst0opt = NULL; | |
926 | } | |
927 | ||
928 | return opt; | |
929 | } | |
930 |