1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Extension Header handling for IPv6 |
4 | * Linux INET6 implementation |
5 | * |
6 | * Authors: |
7 | * Pedro Roque <roque@di.fc.ul.pt> |
8 | * Andi Kleen <ak@muc.de> |
9 | * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> |
10 | */ |
11 | |
12 | /* Changes: |
13 | * yoshfuji : ensure not to overrun while parsing |
14 | * tlv options. |
15 | * Mitsuru KANDA @USAGI and: Remove ipv6_parse_exthdrs(). |
16 | * YOSHIFUJI Hideaki @USAGI Register inbound extension header |
17 | * handlers as inet6_protocol{}. |
18 | */ |
19 | |
20 | #include <linux/errno.h> |
21 | #include <linux/types.h> |
22 | #include <linux/socket.h> |
23 | #include <linux/sockios.h> |
24 | #include <linux/net.h> |
25 | #include <linux/netdevice.h> |
26 | #include <linux/in6.h> |
27 | #include <linux/icmpv6.h> |
28 | #include <linux/slab.h> |
29 | #include <linux/export.h> |
30 | |
31 | #include <net/dst.h> |
32 | #include <net/sock.h> |
33 | #include <net/snmp.h> |
34 | |
35 | #include <net/ipv6.h> |
36 | #include <net/protocol.h> |
37 | #include <net/transp_v6.h> |
38 | #include <net/rawv6.h> |
39 | #include <net/ndisc.h> |
40 | #include <net/ip6_route.h> |
41 | #include <net/addrconf.h> |
42 | #include <net/calipso.h> |
43 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
44 | #include <net/xfrm.h> |
45 | #endif |
46 | #include <linux/seg6.h> |
47 | #include <net/seg6.h> |
48 | #ifdef CONFIG_IPV6_SEG6_HMAC |
49 | #include <net/seg6_hmac.h> |
50 | #endif |
51 | #include <net/rpl.h> |
52 | #include <linux/ioam6.h> |
53 | #include <net/ioam6.h> |
54 | #include <net/dst_metadata.h> |
55 | |
56 | #include <linux/uaccess.h> |
57 | |
58 | /********************* |
59 | Generic functions |
60 | *********************/ |
61 | |
62 | /* An unknown option is detected, decide what to do */ |
63 | |
64 | static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff, |
65 | bool disallow_unknowns) |
66 | { |
67 | if (disallow_unknowns) { |
68 | /* If unknown TLVs are disallowed by configuration |
69 | * then always silently drop packet. Note this also |
70 | * means no ICMP parameter problem is sent which |
71 | * could be a good property to mitigate a reflection DOS |
72 | * attack. |
73 | */ |
74 | |
75 | goto drop; |
76 | } |
77 | |
78 | switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) { |
79 | case 0: /* ignore */ |
80 | return true; |
81 | |
82 | case 1: /* drop packet */ |
83 | break; |
84 | |
85 | case 3: /* Send ICMP if not a multicast address and drop packet */ |
86 | /* Actually, it is redundant check. icmp_send |
87 | will recheck in any case. |
88 | */ |
89 | if (ipv6_addr_is_multicast(addr: &ipv6_hdr(skb)->daddr)) |
90 | break; |
91 | fallthrough; |
92 | case 2: /* send ICMP PARM PROB regardless and drop packet */ |
93 | icmpv6_param_prob_reason(skb, ICMPV6_UNK_OPTION, pos: optoff, |
94 | reason: SKB_DROP_REASON_UNHANDLED_PROTO); |
95 | return false; |
96 | } |
97 | |
98 | drop: |
99 | kfree_skb_reason(skb, reason: SKB_DROP_REASON_UNHANDLED_PROTO); |
100 | return false; |
101 | } |
102 | |
103 | static bool ipv6_hop_ra(struct sk_buff *skb, int optoff); |
104 | static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff); |
105 | static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff); |
106 | static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff); |
107 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
108 | static bool ipv6_dest_hao(struct sk_buff *skb, int optoff); |
109 | #endif |
110 | |
111 | /* Parse tlv encoded option header (hop-by-hop or destination) */ |
112 | |
113 | static bool ip6_parse_tlv(bool hopbyhop, |
114 | struct sk_buff *skb, |
115 | int max_count) |
116 | { |
117 | int len = (skb_transport_header(skb)[1] + 1) << 3; |
118 | const unsigned char *nh = skb_network_header(skb); |
119 | int off = skb_network_header_len(skb); |
120 | bool disallow_unknowns = false; |
121 | int tlv_count = 0; |
122 | int padlen = 0; |
123 | |
124 | if (unlikely(max_count < 0)) { |
125 | disallow_unknowns = true; |
126 | max_count = -max_count; |
127 | } |
128 | |
129 | off += 2; |
130 | len -= 2; |
131 | |
132 | while (len > 0) { |
133 | int optlen, i; |
134 | |
135 | if (nh[off] == IPV6_TLV_PAD1) { |
136 | padlen++; |
137 | if (padlen > 7) |
138 | goto bad; |
139 | off++; |
140 | len--; |
141 | continue; |
142 | } |
143 | if (len < 2) |
144 | goto bad; |
145 | optlen = nh[off + 1] + 2; |
146 | if (optlen > len) |
147 | goto bad; |
148 | |
149 | if (nh[off] == IPV6_TLV_PADN) { |
150 | /* RFC 2460 states that the purpose of PadN is |
151 | * to align the containing header to multiples |
152 | * of 8. 7 is therefore the highest valid value. |
153 | * See also RFC 4942, Section 2.1.9.5. |
154 | */ |
155 | padlen += optlen; |
156 | if (padlen > 7) |
157 | goto bad; |
158 | /* RFC 4942 recommends receiving hosts to |
159 | * actively check PadN payload to contain |
160 | * only zeroes. |
161 | */ |
162 | for (i = 2; i < optlen; i++) { |
163 | if (nh[off + i] != 0) |
164 | goto bad; |
165 | } |
166 | } else { |
167 | tlv_count++; |
168 | if (tlv_count > max_count) |
169 | goto bad; |
170 | |
171 | if (hopbyhop) { |
172 | switch (nh[off]) { |
173 | case IPV6_TLV_ROUTERALERT: |
174 | if (!ipv6_hop_ra(skb, optoff: off)) |
175 | return false; |
176 | break; |
177 | case IPV6_TLV_IOAM: |
178 | if (!ipv6_hop_ioam(skb, optoff: off)) |
179 | return false; |
180 | break; |
181 | case IPV6_TLV_JUMBO: |
182 | if (!ipv6_hop_jumbo(skb, optoff: off)) |
183 | return false; |
184 | break; |
185 | case IPV6_TLV_CALIPSO: |
186 | if (!ipv6_hop_calipso(skb, optoff: off)) |
187 | return false; |
188 | break; |
189 | default: |
190 | if (!ip6_tlvopt_unknown(skb, optoff: off, |
191 | disallow_unknowns)) |
192 | return false; |
193 | break; |
194 | } |
195 | } else { |
196 | switch (nh[off]) { |
197 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
198 | case IPV6_TLV_HAO: |
199 | if (!ipv6_dest_hao(skb, optoff: off)) |
200 | return false; |
201 | break; |
202 | #endif |
203 | default: |
204 | if (!ip6_tlvopt_unknown(skb, optoff: off, |
205 | disallow_unknowns)) |
206 | return false; |
207 | break; |
208 | } |
209 | } |
210 | padlen = 0; |
211 | } |
212 | off += optlen; |
213 | len -= optlen; |
214 | } |
215 | |
216 | if (len == 0) |
217 | return true; |
218 | bad: |
219 | kfree_skb_reason(skb, reason: SKB_DROP_REASON_IP_INHDR); |
220 | return false; |
221 | } |
222 | |
223 | /***************************** |
224 | Destination options header. |
225 | *****************************/ |
226 | |
227 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
228 | static bool ipv6_dest_hao(struct sk_buff *skb, int optoff) |
229 | { |
230 | struct ipv6_destopt_hao *hao; |
231 | struct inet6_skb_parm *opt = IP6CB(skb); |
232 | struct ipv6hdr *ipv6h = ipv6_hdr(skb); |
233 | SKB_DR(reason); |
234 | int ret; |
235 | |
236 | if (opt->dsthao) { |
237 | net_dbg_ratelimited("hao duplicated\n" ); |
238 | goto discard; |
239 | } |
240 | opt->dsthao = opt->dst1; |
241 | opt->dst1 = 0; |
242 | |
243 | hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff); |
244 | |
245 | if (hao->length != 16) { |
246 | net_dbg_ratelimited("hao invalid option length = %d\n" , |
247 | hao->length); |
248 | SKB_DR_SET(reason, IP_INHDR); |
249 | goto discard; |
250 | } |
251 | |
252 | if (!(ipv6_addr_type(addr: &hao->addr) & IPV6_ADDR_UNICAST)) { |
253 | net_dbg_ratelimited("hao is not an unicast addr: %pI6\n" , |
254 | &hao->addr); |
255 | SKB_DR_SET(reason, INVALID_PROTO); |
256 | goto discard; |
257 | } |
258 | |
259 | ret = xfrm6_input_addr(skb, daddr: (xfrm_address_t *)&ipv6h->daddr, |
260 | saddr: (xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS); |
261 | if (unlikely(ret < 0)) { |
262 | SKB_DR_SET(reason, XFRM_POLICY); |
263 | goto discard; |
264 | } |
265 | |
266 | if (skb_cloned(skb)) { |
267 | if (pskb_expand_head(skb, nhead: 0, ntail: 0, GFP_ATOMIC)) |
268 | goto discard; |
269 | |
270 | /* update all variable using below by copied skbuff */ |
271 | hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + |
272 | optoff); |
273 | ipv6h = ipv6_hdr(skb); |
274 | } |
275 | |
276 | if (skb->ip_summed == CHECKSUM_COMPLETE) |
277 | skb->ip_summed = CHECKSUM_NONE; |
278 | |
279 | swap(ipv6h->saddr, hao->addr); |
280 | |
281 | if (skb->tstamp == 0) |
282 | __net_timestamp(skb); |
283 | |
284 | return true; |
285 | |
286 | discard: |
287 | kfree_skb_reason(skb, reason); |
288 | return false; |
289 | } |
290 | #endif |
291 | |
292 | static int ipv6_destopt_rcv(struct sk_buff *skb) |
293 | { |
294 | struct inet6_dev *idev = __in6_dev_get(dev: skb->dev); |
295 | struct inet6_skb_parm *opt = IP6CB(skb); |
296 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
297 | __u16 dstbuf; |
298 | #endif |
299 | struct dst_entry *dst = skb_dst(skb); |
300 | struct net *net = dev_net(dev: skb->dev); |
301 | int extlen; |
302 | |
303 | if (!pskb_may_pull(skb, len: skb_transport_offset(skb) + 8) || |
304 | !pskb_may_pull(skb, len: (skb_transport_offset(skb) + |
305 | ((skb_transport_header(skb)[1] + 1) << 3)))) { |
306 | __IP6_INC_STATS(dev_net(dst->dev), idev, |
307 | IPSTATS_MIB_INHDRERRORS); |
308 | fail_and_free: |
309 | kfree_skb(skb); |
310 | return -1; |
311 | } |
312 | |
313 | extlen = (skb_transport_header(skb)[1] + 1) << 3; |
314 | if (extlen > net->ipv6.sysctl.max_dst_opts_len) |
315 | goto fail_and_free; |
316 | |
317 | opt->lastopt = opt->dst1 = skb_network_header_len(skb); |
318 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
319 | dstbuf = opt->dst1; |
320 | #endif |
321 | |
322 | if (ip6_parse_tlv(hopbyhop: false, skb, max_count: net->ipv6.sysctl.max_dst_opts_cnt)) { |
323 | skb->transport_header += extlen; |
324 | opt = IP6CB(skb); |
325 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
326 | opt->nhoff = dstbuf; |
327 | #else |
328 | opt->nhoff = opt->dst1; |
329 | #endif |
330 | return 1; |
331 | } |
332 | |
333 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); |
334 | return -1; |
335 | } |
336 | |
337 | static void seg6_update_csum(struct sk_buff *skb) |
338 | { |
339 | struct ipv6_sr_hdr *hdr; |
340 | struct in6_addr *addr; |
341 | __be32 from, to; |
342 | |
343 | /* srh is at transport offset and seg_left is already decremented |
344 | * but daddr is not yet updated with next segment |
345 | */ |
346 | |
347 | hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); |
348 | addr = hdr->segments + hdr->segments_left; |
349 | |
350 | hdr->segments_left++; |
351 | from = *(__be32 *)hdr; |
352 | |
353 | hdr->segments_left--; |
354 | to = *(__be32 *)hdr; |
355 | |
356 | /* update skb csum with diff resulting from seg_left decrement */ |
357 | |
358 | update_csum_diff4(skb, from, to); |
359 | |
360 | /* compute csum diff between current and next segment and update */ |
361 | |
362 | update_csum_diff16(skb, from: (__be32 *)(&ipv6_hdr(skb)->daddr), |
363 | to: (__be32 *)addr); |
364 | } |
365 | |
366 | static int ipv6_srh_rcv(struct sk_buff *skb) |
367 | { |
368 | struct inet6_skb_parm *opt = IP6CB(skb); |
369 | struct net *net = dev_net(dev: skb->dev); |
370 | struct ipv6_sr_hdr *hdr; |
371 | struct inet6_dev *idev; |
372 | struct in6_addr *addr; |
373 | int accept_seg6; |
374 | |
375 | hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); |
376 | |
377 | idev = __in6_dev_get(dev: skb->dev); |
378 | |
379 | accept_seg6 = net->ipv6.devconf_all->seg6_enabled; |
380 | if (accept_seg6 > idev->cnf.seg6_enabled) |
381 | accept_seg6 = idev->cnf.seg6_enabled; |
382 | |
383 | if (!accept_seg6) { |
384 | kfree_skb(skb); |
385 | return -1; |
386 | } |
387 | |
388 | #ifdef CONFIG_IPV6_SEG6_HMAC |
389 | if (!seg6_hmac_validate_skb(skb)) { |
390 | kfree_skb(skb); |
391 | return -1; |
392 | } |
393 | #endif |
394 | |
395 | looped_back: |
396 | if (hdr->segments_left == 0) { |
397 | if (hdr->nexthdr == NEXTHDR_IPV6 || hdr->nexthdr == NEXTHDR_IPV4) { |
398 | int offset = (hdr->hdrlen + 1) << 3; |
399 | |
400 | skb_postpull_rcsum(skb, start: skb_network_header(skb), |
401 | len: skb_network_header_len(skb)); |
402 | skb_pull(skb, len: offset); |
403 | skb_postpull_rcsum(skb, start: skb_transport_header(skb), |
404 | len: offset); |
405 | |
406 | skb_reset_network_header(skb); |
407 | skb_reset_transport_header(skb); |
408 | skb->encapsulation = 0; |
409 | if (hdr->nexthdr == NEXTHDR_IPV4) |
410 | skb->protocol = htons(ETH_P_IP); |
411 | __skb_tunnel_rx(skb, dev: skb->dev, net); |
412 | |
413 | netif_rx(skb); |
414 | return -1; |
415 | } |
416 | |
417 | opt->srcrt = skb_network_header_len(skb); |
418 | opt->lastopt = opt->srcrt; |
419 | skb->transport_header += (hdr->hdrlen + 1) << 3; |
420 | opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); |
421 | |
422 | return 1; |
423 | } |
424 | |
425 | if (hdr->segments_left >= (hdr->hdrlen >> 1)) { |
426 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); |
427 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, |
428 | pos: ((&hdr->segments_left) - |
429 | skb_network_header(skb))); |
430 | return -1; |
431 | } |
432 | |
433 | if (skb_cloned(skb)) { |
434 | if (pskb_expand_head(skb, nhead: 0, ntail: 0, GFP_ATOMIC)) { |
435 | __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
436 | IPSTATS_MIB_OUTDISCARDS); |
437 | kfree_skb(skb); |
438 | return -1; |
439 | } |
440 | |
441 | hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); |
442 | } |
443 | |
444 | hdr->segments_left--; |
445 | addr = hdr->segments + hdr->segments_left; |
446 | |
447 | skb_push(skb, len: sizeof(struct ipv6hdr)); |
448 | |
449 | if (skb->ip_summed == CHECKSUM_COMPLETE) |
450 | seg6_update_csum(skb); |
451 | |
452 | ipv6_hdr(skb)->daddr = *addr; |
453 | |
454 | ip6_route_input(skb); |
455 | |
456 | if (skb_dst(skb)->error) { |
457 | dst_input(skb); |
458 | return -1; |
459 | } |
460 | |
461 | if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) { |
462 | if (ipv6_hdr(skb)->hop_limit <= 1) { |
463 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); |
464 | icmpv6_send(skb, ICMPV6_TIME_EXCEED, |
465 | ICMPV6_EXC_HOPLIMIT, info: 0); |
466 | kfree_skb(skb); |
467 | return -1; |
468 | } |
469 | ipv6_hdr(skb)->hop_limit--; |
470 | |
471 | skb_pull(skb, len: sizeof(struct ipv6hdr)); |
472 | goto looped_back; |
473 | } |
474 | |
475 | dst_input(skb); |
476 | |
477 | return -1; |
478 | } |
479 | |
480 | static int ipv6_rpl_srh_rcv(struct sk_buff *skb) |
481 | { |
482 | struct ipv6_rpl_sr_hdr *hdr, *ohdr, *chdr; |
483 | struct inet6_skb_parm *opt = IP6CB(skb); |
484 | struct net *net = dev_net(dev: skb->dev); |
485 | struct inet6_dev *idev; |
486 | struct ipv6hdr *oldhdr; |
487 | unsigned char *buf; |
488 | int accept_rpl_seg; |
489 | int i, err; |
490 | u64 n = 0; |
491 | u32 r; |
492 | |
493 | idev = __in6_dev_get(dev: skb->dev); |
494 | |
495 | accept_rpl_seg = net->ipv6.devconf_all->rpl_seg_enabled; |
496 | if (accept_rpl_seg > idev->cnf.rpl_seg_enabled) |
497 | accept_rpl_seg = idev->cnf.rpl_seg_enabled; |
498 | |
499 | if (!accept_rpl_seg) { |
500 | kfree_skb(skb); |
501 | return -1; |
502 | } |
503 | |
504 | looped_back: |
505 | hdr = (struct ipv6_rpl_sr_hdr *)skb_transport_header(skb); |
506 | |
507 | if (hdr->segments_left == 0) { |
508 | if (hdr->nexthdr == NEXTHDR_IPV6) { |
509 | int offset = (hdr->hdrlen + 1) << 3; |
510 | |
511 | skb_postpull_rcsum(skb, start: skb_network_header(skb), |
512 | len: skb_network_header_len(skb)); |
513 | skb_pull(skb, len: offset); |
514 | skb_postpull_rcsum(skb, start: skb_transport_header(skb), |
515 | len: offset); |
516 | |
517 | skb_reset_network_header(skb); |
518 | skb_reset_transport_header(skb); |
519 | skb->encapsulation = 0; |
520 | |
521 | __skb_tunnel_rx(skb, dev: skb->dev, net); |
522 | |
523 | netif_rx(skb); |
524 | return -1; |
525 | } |
526 | |
527 | opt->srcrt = skb_network_header_len(skb); |
528 | opt->lastopt = opt->srcrt; |
529 | skb->transport_header += (hdr->hdrlen + 1) << 3; |
530 | opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); |
531 | |
532 | return 1; |
533 | } |
534 | |
535 | n = (hdr->hdrlen << 3) - hdr->pad - (16 - hdr->cmpre); |
536 | r = do_div(n, (16 - hdr->cmpri)); |
537 | /* checks if calculation was without remainder and n fits into |
538 | * unsigned char which is segments_left field. Should not be |
539 | * higher than that. |
540 | */ |
541 | if (r || (n + 1) > 255) { |
542 | kfree_skb(skb); |
543 | return -1; |
544 | } |
545 | |
546 | if (hdr->segments_left > n + 1) { |
547 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); |
548 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, |
549 | pos: ((&hdr->segments_left) - |
550 | skb_network_header(skb))); |
551 | return -1; |
552 | } |
553 | |
554 | hdr->segments_left--; |
555 | i = n - hdr->segments_left; |
556 | |
557 | buf = kcalloc(struct_size(hdr, segments.addr, n + 2), size: 2, GFP_ATOMIC); |
558 | if (unlikely(!buf)) { |
559 | kfree_skb(skb); |
560 | return -1; |
561 | } |
562 | |
563 | ohdr = (struct ipv6_rpl_sr_hdr *)buf; |
564 | ipv6_rpl_srh_decompress(outhdr: ohdr, inhdr: hdr, daddr: &ipv6_hdr(skb)->daddr, n); |
565 | chdr = (struct ipv6_rpl_sr_hdr *)(buf + ((ohdr->hdrlen + 1) << 3)); |
566 | |
567 | if (ipv6_addr_is_multicast(addr: &ohdr->rpl_segaddr[i])) { |
568 | kfree_skb(skb); |
569 | kfree(objp: buf); |
570 | return -1; |
571 | } |
572 | |
573 | err = ipv6_chk_rpl_srh_loop(net, segs: ohdr->rpl_segaddr, nsegs: n + 1); |
574 | if (err) { |
575 | icmpv6_send(skb, ICMPV6_PARAMPROB, code: 0, info: 0); |
576 | kfree_skb(skb); |
577 | kfree(objp: buf); |
578 | return -1; |
579 | } |
580 | |
581 | swap(ipv6_hdr(skb)->daddr, ohdr->rpl_segaddr[i]); |
582 | |
583 | ipv6_rpl_srh_compress(outhdr: chdr, inhdr: ohdr, daddr: &ipv6_hdr(skb)->daddr, n); |
584 | |
585 | oldhdr = ipv6_hdr(skb); |
586 | |
587 | skb_pull(skb, len: ((hdr->hdrlen + 1) << 3)); |
588 | skb_postpull_rcsum(skb, start: oldhdr, |
589 | len: sizeof(struct ipv6hdr) + ((hdr->hdrlen + 1) << 3)); |
590 | if (unlikely(!hdr->segments_left)) { |
591 | if (pskb_expand_head(skb, nhead: sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3), ntail: 0, |
592 | GFP_ATOMIC)) { |
593 | __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_OUTDISCARDS); |
594 | kfree_skb(skb); |
595 | kfree(objp: buf); |
596 | return -1; |
597 | } |
598 | |
599 | oldhdr = ipv6_hdr(skb); |
600 | } |
601 | skb_push(skb, len: ((chdr->hdrlen + 1) << 3) + sizeof(struct ipv6hdr)); |
602 | skb_reset_network_header(skb); |
603 | skb_mac_header_rebuild(skb); |
604 | skb_set_transport_header(skb, offset: sizeof(struct ipv6hdr)); |
605 | |
606 | memmove(ipv6_hdr(skb), oldhdr, sizeof(struct ipv6hdr)); |
607 | memcpy(skb_transport_header(skb), chdr, (chdr->hdrlen + 1) << 3); |
608 | |
609 | ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); |
610 | skb_postpush_rcsum(skb, start: ipv6_hdr(skb), |
611 | len: sizeof(struct ipv6hdr) + ((chdr->hdrlen + 1) << 3)); |
612 | |
613 | kfree(objp: buf); |
614 | |
615 | ip6_route_input(skb); |
616 | |
617 | if (skb_dst(skb)->error) { |
618 | dst_input(skb); |
619 | return -1; |
620 | } |
621 | |
622 | if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) { |
623 | if (ipv6_hdr(skb)->hop_limit <= 1) { |
624 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); |
625 | icmpv6_send(skb, ICMPV6_TIME_EXCEED, |
626 | ICMPV6_EXC_HOPLIMIT, info: 0); |
627 | kfree_skb(skb); |
628 | return -1; |
629 | } |
630 | ipv6_hdr(skb)->hop_limit--; |
631 | |
632 | skb_pull(skb, len: sizeof(struct ipv6hdr)); |
633 | goto looped_back; |
634 | } |
635 | |
636 | dst_input(skb); |
637 | |
638 | return -1; |
639 | } |
640 | |
641 | /******************************** |
642 | Routing header. |
643 | ********************************/ |
644 | |
645 | /* called with rcu_read_lock() */ |
646 | static int ipv6_rthdr_rcv(struct sk_buff *skb) |
647 | { |
648 | struct inet6_dev *idev = __in6_dev_get(dev: skb->dev); |
649 | struct inet6_skb_parm *opt = IP6CB(skb); |
650 | struct in6_addr *addr = NULL; |
651 | int n, i; |
652 | struct ipv6_rt_hdr *hdr; |
653 | struct rt0_hdr *rthdr; |
654 | struct net *net = dev_net(dev: skb->dev); |
655 | int accept_source_route = net->ipv6.devconf_all->accept_source_route; |
656 | |
657 | if (idev && accept_source_route > idev->cnf.accept_source_route) |
658 | accept_source_route = idev->cnf.accept_source_route; |
659 | |
660 | if (!pskb_may_pull(skb, len: skb_transport_offset(skb) + 8) || |
661 | !pskb_may_pull(skb, len: (skb_transport_offset(skb) + |
662 | ((skb_transport_header(skb)[1] + 1) << 3)))) { |
663 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); |
664 | kfree_skb(skb); |
665 | return -1; |
666 | } |
667 | |
668 | hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); |
669 | |
670 | if (ipv6_addr_is_multicast(addr: &ipv6_hdr(skb)->daddr) || |
671 | skb->pkt_type != PACKET_HOST) { |
672 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); |
673 | kfree_skb(skb); |
674 | return -1; |
675 | } |
676 | |
677 | switch (hdr->type) { |
678 | case IPV6_SRCRT_TYPE_4: |
679 | /* segment routing */ |
680 | return ipv6_srh_rcv(skb); |
681 | case IPV6_SRCRT_TYPE_3: |
682 | /* rpl segment routing */ |
683 | return ipv6_rpl_srh_rcv(skb); |
684 | default: |
685 | break; |
686 | } |
687 | |
688 | looped_back: |
689 | if (hdr->segments_left == 0) { |
690 | switch (hdr->type) { |
691 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
692 | case IPV6_SRCRT_TYPE_2: |
693 | /* Silently discard type 2 header unless it was |
694 | * processed by own |
695 | */ |
696 | if (!addr) { |
697 | __IP6_INC_STATS(net, idev, |
698 | IPSTATS_MIB_INADDRERRORS); |
699 | kfree_skb(skb); |
700 | return -1; |
701 | } |
702 | break; |
703 | #endif |
704 | default: |
705 | break; |
706 | } |
707 | |
708 | opt->lastopt = opt->srcrt = skb_network_header_len(skb); |
709 | skb->transport_header += (hdr->hdrlen + 1) << 3; |
710 | opt->dst0 = opt->dst1; |
711 | opt->dst1 = 0; |
712 | opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); |
713 | return 1; |
714 | } |
715 | |
716 | switch (hdr->type) { |
717 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
718 | case IPV6_SRCRT_TYPE_2: |
719 | if (accept_source_route < 0) |
720 | goto unknown_rh; |
721 | /* Silently discard invalid RTH type 2 */ |
722 | if (hdr->hdrlen != 2 || hdr->segments_left != 1) { |
723 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); |
724 | kfree_skb(skb); |
725 | return -1; |
726 | } |
727 | break; |
728 | #endif |
729 | default: |
730 | goto unknown_rh; |
731 | } |
732 | |
733 | /* |
734 | * This is the routing header forwarding algorithm from |
735 | * RFC 2460, page 16. |
736 | */ |
737 | |
738 | n = hdr->hdrlen >> 1; |
739 | |
740 | if (hdr->segments_left > n) { |
741 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); |
742 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, |
743 | pos: ((&hdr->segments_left) - |
744 | skb_network_header(skb))); |
745 | return -1; |
746 | } |
747 | |
748 | /* We are about to mangle packet header. Be careful! |
749 | Do not damage packets queued somewhere. |
750 | */ |
751 | if (skb_cloned(skb)) { |
752 | /* the copy is a forwarded packet */ |
753 | if (pskb_expand_head(skb, nhead: 0, ntail: 0, GFP_ATOMIC)) { |
754 | __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
755 | IPSTATS_MIB_OUTDISCARDS); |
756 | kfree_skb(skb); |
757 | return -1; |
758 | } |
759 | hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb); |
760 | } |
761 | |
762 | if (skb->ip_summed == CHECKSUM_COMPLETE) |
763 | skb->ip_summed = CHECKSUM_NONE; |
764 | |
765 | i = n - --hdr->segments_left; |
766 | |
767 | rthdr = (struct rt0_hdr *) hdr; |
768 | addr = rthdr->addr; |
769 | addr += i - 1; |
770 | |
771 | switch (hdr->type) { |
772 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
773 | case IPV6_SRCRT_TYPE_2: |
774 | if (xfrm6_input_addr(skb, daddr: (xfrm_address_t *)addr, |
775 | saddr: (xfrm_address_t *)&ipv6_hdr(skb)->saddr, |
776 | IPPROTO_ROUTING) < 0) { |
777 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); |
778 | kfree_skb(skb); |
779 | return -1; |
780 | } |
781 | if (!ipv6_chk_home_addr(net: dev_net(dev: skb_dst(skb)->dev), addr)) { |
782 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); |
783 | kfree_skb(skb); |
784 | return -1; |
785 | } |
786 | break; |
787 | #endif |
788 | default: |
789 | break; |
790 | } |
791 | |
792 | if (ipv6_addr_is_multicast(addr)) { |
793 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); |
794 | kfree_skb(skb); |
795 | return -1; |
796 | } |
797 | |
798 | swap(*addr, ipv6_hdr(skb)->daddr); |
799 | |
800 | ip6_route_input(skb); |
801 | if (skb_dst(skb)->error) { |
802 | skb_push(skb, len: skb->data - skb_network_header(skb)); |
803 | dst_input(skb); |
804 | return -1; |
805 | } |
806 | |
807 | if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) { |
808 | if (ipv6_hdr(skb)->hop_limit <= 1) { |
809 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); |
810 | icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, |
811 | info: 0); |
812 | kfree_skb(skb); |
813 | return -1; |
814 | } |
815 | ipv6_hdr(skb)->hop_limit--; |
816 | goto looped_back; |
817 | } |
818 | |
819 | skb_push(skb, len: skb->data - skb_network_header(skb)); |
820 | dst_input(skb); |
821 | return -1; |
822 | |
823 | unknown_rh: |
824 | __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); |
825 | icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, |
826 | pos: (&hdr->type) - skb_network_header(skb)); |
827 | return -1; |
828 | } |
829 | |
830 | static const struct inet6_protocol rthdr_protocol = { |
831 | .handler = ipv6_rthdr_rcv, |
832 | .flags = INET6_PROTO_NOPOLICY, |
833 | }; |
834 | |
835 | static const struct inet6_protocol destopt_protocol = { |
836 | .handler = ipv6_destopt_rcv, |
837 | .flags = INET6_PROTO_NOPOLICY, |
838 | }; |
839 | |
840 | static const struct inet6_protocol nodata_protocol = { |
841 | .handler = dst_discard, |
842 | .flags = INET6_PROTO_NOPOLICY, |
843 | }; |
844 | |
845 | int __init ipv6_exthdrs_init(void) |
846 | { |
847 | int ret; |
848 | |
849 | ret = inet6_add_protocol(prot: &rthdr_protocol, IPPROTO_ROUTING); |
850 | if (ret) |
851 | goto out; |
852 | |
853 | ret = inet6_add_protocol(prot: &destopt_protocol, IPPROTO_DSTOPTS); |
854 | if (ret) |
855 | goto out_rthdr; |
856 | |
857 | ret = inet6_add_protocol(prot: &nodata_protocol, IPPROTO_NONE); |
858 | if (ret) |
859 | goto out_destopt; |
860 | |
861 | out: |
862 | return ret; |
863 | out_destopt: |
864 | inet6_del_protocol(prot: &destopt_protocol, IPPROTO_DSTOPTS); |
865 | out_rthdr: |
866 | inet6_del_protocol(prot: &rthdr_protocol, IPPROTO_ROUTING); |
867 | goto out; |
868 | }; |
869 | |
870 | void ipv6_exthdrs_exit(void) |
871 | { |
872 | inet6_del_protocol(prot: &nodata_protocol, IPPROTO_NONE); |
873 | inet6_del_protocol(prot: &destopt_protocol, IPPROTO_DSTOPTS); |
874 | inet6_del_protocol(prot: &rthdr_protocol, IPPROTO_ROUTING); |
875 | } |
876 | |
877 | /********************************** |
878 | Hop-by-hop options. |
879 | **********************************/ |
880 | |
881 | /* |
882 | * Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input(). |
883 | */ |
884 | static inline struct net *ipv6_skb_net(struct sk_buff *skb) |
885 | { |
886 | return skb_dst(skb) ? dev_net(dev: skb_dst(skb)->dev) : dev_net(dev: skb->dev); |
887 | } |
888 | |
889 | /* Router Alert as of RFC 2711 */ |
890 | |
891 | static bool ipv6_hop_ra(struct sk_buff *skb, int optoff) |
892 | { |
893 | const unsigned char *nh = skb_network_header(skb); |
894 | |
895 | if (nh[optoff + 1] == 2) { |
896 | IP6CB(skb)->flags |= IP6SKB_ROUTERALERT; |
897 | memcpy(&IP6CB(skb)->ra, nh + optoff + 2, sizeof(IP6CB(skb)->ra)); |
898 | return true; |
899 | } |
900 | net_dbg_ratelimited("ipv6_hop_ra: wrong RA length %d\n" , |
901 | nh[optoff + 1]); |
902 | kfree_skb_reason(skb, reason: SKB_DROP_REASON_IP_INHDR); |
903 | return false; |
904 | } |
905 | |
906 | /* IOAM */ |
907 | |
908 | static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff) |
909 | { |
910 | struct ioam6_trace_hdr *trace; |
911 | struct ioam6_namespace *ns; |
912 | struct ioam6_hdr *hdr; |
913 | |
914 | /* Bad alignment (must be 4n-aligned) */ |
915 | if (optoff & 3) |
916 | goto drop; |
917 | |
918 | /* Ignore if IOAM is not enabled on ingress */ |
919 | if (!__in6_dev_get(dev: skb->dev)->cnf.ioam6_enabled) |
920 | goto ignore; |
921 | |
922 | /* Truncated Option header */ |
923 | hdr = (struct ioam6_hdr *)(skb_network_header(skb) + optoff); |
924 | if (hdr->opt_len < 2) |
925 | goto drop; |
926 | |
927 | switch (hdr->type) { |
928 | case IOAM6_TYPE_PREALLOC: |
929 | /* Truncated Pre-allocated Trace header */ |
930 | if (hdr->opt_len < 2 + sizeof(*trace)) |
931 | goto drop; |
932 | |
933 | /* Malformed Pre-allocated Trace header */ |
934 | trace = (struct ioam6_trace_hdr *)((u8 *)hdr + sizeof(*hdr)); |
935 | if (hdr->opt_len < 2 + sizeof(*trace) + trace->remlen * 4) |
936 | goto drop; |
937 | |
938 | /* Ignore if the IOAM namespace is unknown */ |
939 | ns = ioam6_namespace(net: ipv6_skb_net(skb), id: trace->namespace_id); |
940 | if (!ns) |
941 | goto ignore; |
942 | |
943 | if (!skb_valid_dst(skb)) |
944 | ip6_route_input(skb); |
945 | |
946 | ioam6_fill_trace_data(skb, ns, trace, is_input: true); |
947 | break; |
948 | default: |
949 | break; |
950 | } |
951 | |
952 | ignore: |
953 | return true; |
954 | |
955 | drop: |
956 | kfree_skb_reason(skb, reason: SKB_DROP_REASON_IP_INHDR); |
957 | return false; |
958 | } |
959 | |
960 | /* Jumbo payload */ |
961 | |
962 | static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff) |
963 | { |
964 | const unsigned char *nh = skb_network_header(skb); |
965 | SKB_DR(reason); |
966 | u32 pkt_len; |
967 | |
968 | if (nh[optoff + 1] != 4 || (optoff & 3) != 2) { |
969 | net_dbg_ratelimited("ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n" , |
970 | nh[optoff+1]); |
971 | SKB_DR_SET(reason, IP_INHDR); |
972 | goto drop; |
973 | } |
974 | |
975 | pkt_len = ntohl(*(__be32 *)(nh + optoff + 2)); |
976 | if (pkt_len <= IPV6_MAXPLEN) { |
977 | icmpv6_param_prob_reason(skb, ICMPV6_HDR_FIELD, pos: optoff + 2, |
978 | reason: SKB_DROP_REASON_IP_INHDR); |
979 | return false; |
980 | } |
981 | if (ipv6_hdr(skb)->payload_len) { |
982 | icmpv6_param_prob_reason(skb, ICMPV6_HDR_FIELD, pos: optoff, |
983 | reason: SKB_DROP_REASON_IP_INHDR); |
984 | return false; |
985 | } |
986 | |
987 | if (pkt_len > skb->len - sizeof(struct ipv6hdr)) { |
988 | SKB_DR_SET(reason, PKT_TOO_SMALL); |
989 | goto drop; |
990 | } |
991 | |
992 | if (pskb_trim_rcsum(skb, len: pkt_len + sizeof(struct ipv6hdr))) |
993 | goto drop; |
994 | |
995 | IP6CB(skb)->flags |= IP6SKB_JUMBOGRAM; |
996 | return true; |
997 | |
998 | drop: |
999 | kfree_skb_reason(skb, reason); |
1000 | return false; |
1001 | } |
1002 | |
1003 | /* CALIPSO RFC 5570 */ |
1004 | |
1005 | static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff) |
1006 | { |
1007 | const unsigned char *nh = skb_network_header(skb); |
1008 | |
1009 | if (nh[optoff + 1] < 8) |
1010 | goto drop; |
1011 | |
1012 | if (nh[optoff + 6] * 4 + 8 > nh[optoff + 1]) |
1013 | goto drop; |
1014 | |
1015 | if (!calipso_validate(skb, option: nh + optoff)) |
1016 | goto drop; |
1017 | |
1018 | return true; |
1019 | |
1020 | drop: |
1021 | kfree_skb_reason(skb, reason: SKB_DROP_REASON_IP_INHDR); |
1022 | return false; |
1023 | } |
1024 | |
1025 | int ipv6_parse_hopopts(struct sk_buff *skb) |
1026 | { |
1027 | struct inet6_skb_parm *opt = IP6CB(skb); |
1028 | struct net *net = dev_net(dev: skb->dev); |
1029 | int extlen; |
1030 | |
1031 | /* |
1032 | * skb_network_header(skb) is equal to skb->data, and |
1033 | * skb_network_header_len(skb) is always equal to |
1034 | * sizeof(struct ipv6hdr) by definition of |
1035 | * hop-by-hop options. |
1036 | */ |
1037 | if (!pskb_may_pull(skb, len: sizeof(struct ipv6hdr) + 8) || |
1038 | !pskb_may_pull(skb, len: (sizeof(struct ipv6hdr) + |
1039 | ((skb_transport_header(skb)[1] + 1) << 3)))) { |
1040 | fail_and_free: |
1041 | kfree_skb(skb); |
1042 | return -1; |
1043 | } |
1044 | |
1045 | extlen = (skb_transport_header(skb)[1] + 1) << 3; |
1046 | if (extlen > net->ipv6.sysctl.max_hbh_opts_len) |
1047 | goto fail_and_free; |
1048 | |
1049 | opt->flags |= IP6SKB_HOPBYHOP; |
1050 | if (ip6_parse_tlv(hopbyhop: true, skb, max_count: net->ipv6.sysctl.max_hbh_opts_cnt)) { |
1051 | skb->transport_header += extlen; |
1052 | opt = IP6CB(skb); |
1053 | opt->nhoff = sizeof(struct ipv6hdr); |
1054 | return 1; |
1055 | } |
1056 | return -1; |
1057 | } |
1058 | |
1059 | /* |
1060 | * Creating outbound headers. |
1061 | * |
1062 | * "build" functions work when skb is filled from head to tail (datagram) |
1063 | * "push" functions work when headers are added from tail to head (tcp) |
1064 | * |
1065 | * In both cases we assume, that caller reserved enough room |
1066 | * for headers. |
1067 | */ |
1068 | |
1069 | static void ipv6_push_rthdr0(struct sk_buff *skb, u8 *proto, |
1070 | struct ipv6_rt_hdr *opt, |
1071 | struct in6_addr **addr_p, struct in6_addr *saddr) |
1072 | { |
1073 | struct rt0_hdr *phdr, *ihdr; |
1074 | int hops; |
1075 | |
1076 | ihdr = (struct rt0_hdr *) opt; |
1077 | |
1078 | phdr = skb_push(skb, len: (ihdr->rt_hdr.hdrlen + 1) << 3); |
1079 | memcpy(phdr, ihdr, sizeof(struct rt0_hdr)); |
1080 | |
1081 | hops = ihdr->rt_hdr.hdrlen >> 1; |
1082 | |
1083 | if (hops > 1) |
1084 | memcpy(phdr->addr, ihdr->addr + 1, |
1085 | (hops - 1) * sizeof(struct in6_addr)); |
1086 | |
1087 | phdr->addr[hops - 1] = **addr_p; |
1088 | *addr_p = ihdr->addr; |
1089 | |
1090 | phdr->rt_hdr.nexthdr = *proto; |
1091 | *proto = NEXTHDR_ROUTING; |
1092 | } |
1093 | |
1094 | static void ipv6_push_rthdr4(struct sk_buff *skb, u8 *proto, |
1095 | struct ipv6_rt_hdr *opt, |
1096 | struct in6_addr **addr_p, struct in6_addr *saddr) |
1097 | { |
1098 | struct ipv6_sr_hdr *sr_phdr, *sr_ihdr; |
1099 | int plen, hops; |
1100 | |
1101 | sr_ihdr = (struct ipv6_sr_hdr *)opt; |
1102 | plen = (sr_ihdr->hdrlen + 1) << 3; |
1103 | |
1104 | sr_phdr = skb_push(skb, len: plen); |
1105 | memcpy(sr_phdr, sr_ihdr, sizeof(struct ipv6_sr_hdr)); |
1106 | |
1107 | hops = sr_ihdr->first_segment + 1; |
1108 | memcpy(sr_phdr->segments + 1, sr_ihdr->segments + 1, |
1109 | (hops - 1) * sizeof(struct in6_addr)); |
1110 | |
1111 | sr_phdr->segments[0] = **addr_p; |
1112 | *addr_p = &sr_ihdr->segments[sr_ihdr->segments_left]; |
1113 | |
1114 | if (sr_ihdr->hdrlen > hops * 2) { |
1115 | int tlvs_offset, tlvs_length; |
1116 | |
1117 | tlvs_offset = (1 + hops * 2) << 3; |
1118 | tlvs_length = (sr_ihdr->hdrlen - hops * 2) << 3; |
1119 | memcpy((char *)sr_phdr + tlvs_offset, |
1120 | (char *)sr_ihdr + tlvs_offset, tlvs_length); |
1121 | } |
1122 | |
1123 | #ifdef CONFIG_IPV6_SEG6_HMAC |
1124 | if (sr_has_hmac(sr_phdr)) { |
1125 | struct net *net = NULL; |
1126 | |
1127 | if (skb->dev) |
1128 | net = dev_net(dev: skb->dev); |
1129 | else if (skb->sk) |
1130 | net = sock_net(sk: skb->sk); |
1131 | |
1132 | WARN_ON(!net); |
1133 | |
1134 | if (net) |
1135 | seg6_push_hmac(net, saddr, srh: sr_phdr); |
1136 | } |
1137 | #endif |
1138 | |
1139 | sr_phdr->nexthdr = *proto; |
1140 | *proto = NEXTHDR_ROUTING; |
1141 | } |
1142 | |
1143 | static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto, |
1144 | struct ipv6_rt_hdr *opt, |
1145 | struct in6_addr **addr_p, struct in6_addr *saddr) |
1146 | { |
1147 | switch (opt->type) { |
1148 | case IPV6_SRCRT_TYPE_0: |
1149 | case IPV6_SRCRT_STRICT: |
1150 | case IPV6_SRCRT_TYPE_2: |
1151 | ipv6_push_rthdr0(skb, proto, opt, addr_p, saddr); |
1152 | break; |
1153 | case IPV6_SRCRT_TYPE_4: |
1154 | ipv6_push_rthdr4(skb, proto, opt, addr_p, saddr); |
1155 | break; |
1156 | default: |
1157 | break; |
1158 | } |
1159 | } |
1160 | |
1161 | static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt) |
1162 | { |
1163 | struct ipv6_opt_hdr *h = skb_push(skb, ipv6_optlen(opt)); |
1164 | |
1165 | memcpy(h, opt, ipv6_optlen(opt)); |
1166 | h->nexthdr = *proto; |
1167 | *proto = type; |
1168 | } |
1169 | |
1170 | void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, |
1171 | u8 *proto, |
1172 | struct in6_addr **daddr, struct in6_addr *saddr) |
1173 | { |
1174 | if (opt->srcrt) { |
1175 | ipv6_push_rthdr(skb, proto, opt: opt->srcrt, addr_p: daddr, saddr); |
1176 | /* |
1177 | * IPV6_RTHDRDSTOPTS is ignored |
1178 | * unless IPV6_RTHDR is set (RFC3542). |
1179 | */ |
1180 | if (opt->dst0opt) |
1181 | ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt: opt->dst0opt); |
1182 | } |
1183 | if (opt->hopopt) |
1184 | ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt: opt->hopopt); |
1185 | } |
1186 | |
1187 | void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto) |
1188 | { |
1189 | if (opt->dst1opt) |
1190 | ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt: opt->dst1opt); |
1191 | } |
1192 | EXPORT_SYMBOL(ipv6_push_frag_opts); |
1193 | |
1194 | struct ipv6_txoptions * |
1195 | ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt) |
1196 | { |
1197 | struct ipv6_txoptions *opt2; |
1198 | |
1199 | opt2 = sock_kmalloc(sk, size: opt->tot_len, GFP_ATOMIC); |
1200 | if (opt2) { |
1201 | long dif = (char *)opt2 - (char *)opt; |
1202 | memcpy(opt2, opt, opt->tot_len); |
1203 | if (opt2->hopopt) |
1204 | *((char **)&opt2->hopopt) += dif; |
1205 | if (opt2->dst0opt) |
1206 | *((char **)&opt2->dst0opt) += dif; |
1207 | if (opt2->dst1opt) |
1208 | *((char **)&opt2->dst1opt) += dif; |
1209 | if (opt2->srcrt) |
1210 | *((char **)&opt2->srcrt) += dif; |
1211 | refcount_set(r: &opt2->refcnt, n: 1); |
1212 | } |
1213 | return opt2; |
1214 | } |
1215 | EXPORT_SYMBOL_GPL(ipv6_dup_options); |
1216 | |
1217 | static void ipv6_renew_option(int renewtype, |
1218 | struct ipv6_opt_hdr **dest, |
1219 | struct ipv6_opt_hdr *old, |
1220 | struct ipv6_opt_hdr *new, |
1221 | int newtype, char **p) |
1222 | { |
1223 | struct ipv6_opt_hdr *src; |
1224 | |
1225 | src = (renewtype == newtype ? new : old); |
1226 | if (!src) |
1227 | return; |
1228 | |
1229 | memcpy(*p, src, ipv6_optlen(src)); |
1230 | *dest = (struct ipv6_opt_hdr *)*p; |
1231 | *p += CMSG_ALIGN(ipv6_optlen(*dest)); |
1232 | } |
1233 | |
1234 | /** |
1235 | * ipv6_renew_options - replace a specific ext hdr with a new one. |
1236 | * |
1237 | * @sk: sock from which to allocate memory |
1238 | * @opt: original options |
1239 | * @newtype: option type to replace in @opt |
1240 | * @newopt: new option of type @newtype to replace (user-mem) |
1241 | * |
1242 | * Returns a new set of options which is a copy of @opt with the |
1243 | * option type @newtype replaced with @newopt. |
1244 | * |
1245 | * @opt may be NULL, in which case a new set of options is returned |
1246 | * containing just @newopt. |
1247 | * |
1248 | * @newopt may be NULL, in which case the specified option type is |
1249 | * not copied into the new set of options. |
1250 | * |
1251 | * The new set of options is allocated from the socket option memory |
1252 | * buffer of @sk. |
1253 | */ |
1254 | struct ipv6_txoptions * |
1255 | ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt, |
1256 | int newtype, struct ipv6_opt_hdr *newopt) |
1257 | { |
1258 | int tot_len = 0; |
1259 | char *p; |
1260 | struct ipv6_txoptions *opt2; |
1261 | |
1262 | if (opt) { |
1263 | if (newtype != IPV6_HOPOPTS && opt->hopopt) |
1264 | tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt)); |
1265 | if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt) |
1266 | tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt)); |
1267 | if (newtype != IPV6_RTHDR && opt->srcrt) |
1268 | tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt)); |
1269 | if (newtype != IPV6_DSTOPTS && opt->dst1opt) |
1270 | tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt)); |
1271 | } |
1272 | |
1273 | if (newopt) |
1274 | tot_len += CMSG_ALIGN(ipv6_optlen(newopt)); |
1275 | |
1276 | if (!tot_len) |
1277 | return NULL; |
1278 | |
1279 | tot_len += sizeof(*opt2); |
1280 | opt2 = sock_kmalloc(sk, size: tot_len, GFP_ATOMIC); |
1281 | if (!opt2) |
1282 | return ERR_PTR(error: -ENOBUFS); |
1283 | |
1284 | memset(opt2, 0, tot_len); |
1285 | refcount_set(r: &opt2->refcnt, n: 1); |
1286 | opt2->tot_len = tot_len; |
1287 | p = (char *)(opt2 + 1); |
1288 | |
1289 | ipv6_renew_option(IPV6_HOPOPTS, dest: &opt2->hopopt, |
1290 | old: (opt ? opt->hopopt : NULL), |
1291 | new: newopt, newtype, p: &p); |
1292 | ipv6_renew_option(IPV6_RTHDRDSTOPTS, dest: &opt2->dst0opt, |
1293 | old: (opt ? opt->dst0opt : NULL), |
1294 | new: newopt, newtype, p: &p); |
1295 | ipv6_renew_option(IPV6_RTHDR, |
1296 | dest: (struct ipv6_opt_hdr **)&opt2->srcrt, |
1297 | old: (opt ? (struct ipv6_opt_hdr *)opt->srcrt : NULL), |
1298 | new: newopt, newtype, p: &p); |
1299 | ipv6_renew_option(IPV6_DSTOPTS, dest: &opt2->dst1opt, |
1300 | old: (opt ? opt->dst1opt : NULL), |
1301 | new: newopt, newtype, p: &p); |
1302 | |
1303 | opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) + |
1304 | (opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) + |
1305 | (opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0); |
1306 | opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0); |
1307 | |
1308 | return opt2; |
1309 | } |
1310 | |
1311 | struct ipv6_txoptions *__ipv6_fixup_options(struct ipv6_txoptions *opt_space, |
1312 | struct ipv6_txoptions *opt) |
1313 | { |
1314 | /* |
1315 | * ignore the dest before srcrt unless srcrt is being included. |
1316 | * --yoshfuji |
1317 | */ |
1318 | if (opt->dst0opt && !opt->srcrt) { |
1319 | if (opt_space != opt) { |
1320 | memcpy(opt_space, opt, sizeof(*opt_space)); |
1321 | opt = opt_space; |
1322 | } |
1323 | opt->opt_nflen -= ipv6_optlen(opt->dst0opt); |
1324 | opt->dst0opt = NULL; |
1325 | } |
1326 | |
1327 | return opt; |
1328 | } |
1329 | EXPORT_SYMBOL_GPL(__ipv6_fixup_options); |
1330 | |
1331 | /** |
1332 | * fl6_update_dst - update flowi destination address with info given |
1333 | * by srcrt option, if any. |
1334 | * |
1335 | * @fl6: flowi6 for which daddr is to be updated |
1336 | * @opt: struct ipv6_txoptions in which to look for srcrt opt |
1337 | * @orig: copy of original daddr address if modified |
1338 | * |
1339 | * Returns NULL if no txoptions or no srcrt, otherwise returns orig |
1340 | * and initial value of fl6->daddr set in orig |
1341 | */ |
1342 | struct in6_addr *fl6_update_dst(struct flowi6 *fl6, |
1343 | const struct ipv6_txoptions *opt, |
1344 | struct in6_addr *orig) |
1345 | { |
1346 | if (!opt || !opt->srcrt) |
1347 | return NULL; |
1348 | |
1349 | *orig = fl6->daddr; |
1350 | |
1351 | switch (opt->srcrt->type) { |
1352 | case IPV6_SRCRT_TYPE_0: |
1353 | case IPV6_SRCRT_STRICT: |
1354 | case IPV6_SRCRT_TYPE_2: |
1355 | fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr; |
1356 | break; |
1357 | case IPV6_SRCRT_TYPE_4: |
1358 | { |
1359 | struct ipv6_sr_hdr *srh = (struct ipv6_sr_hdr *)opt->srcrt; |
1360 | |
1361 | fl6->daddr = srh->segments[srh->segments_left]; |
1362 | break; |
1363 | } |
1364 | default: |
1365 | return NULL; |
1366 | } |
1367 | |
1368 | return orig; |
1369 | } |
1370 | EXPORT_SYMBOL_GPL(fl6_update_dst); |
1371 | |