1 /*
2 * common UDP/RAW code
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 */
13
14 #include <linux/capability.h>
15 #include <linux/errno.h>
16 #include <linux/types.h>
17 #include <linux/kernel.h>
18 #include <linux/interrupt.h>
19 #include <linux/socket.h>
20 #include <linux/sockios.h>
21 #include <linux/in6.h>
22 #include <linux/ipv6.h>
23 #include <linux/route.h>
24 #include <linux/slab.h>
25 #include <linux/export.h>
26
27 #include <net/ipv6.h>
28 #include <net/ndisc.h>
29 #include <net/addrconf.h>
30 #include <net/transp_v6.h>
31 #include <net/ip6_route.h>
32 #include <net/tcp_states.h>
33 #include <net/dsfield.h>
34
35 #include <linux/errqueue.h>
36 #include <asm/uaccess.h>
37
ipv6_mapped_addr_any(const struct in6_addr * a)38 static bool ipv6_mapped_addr_any(const struct in6_addr *a)
39 {
40 return ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0);
41 }
42
ip6_datagram_connect(struct sock * sk,struct sockaddr * uaddr,int addr_len)43 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
44 {
45 struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
46 struct inet_sock *inet = inet_sk(sk);
47 struct ipv6_pinfo *np = inet6_sk(sk);
48 struct in6_addr *daddr, *final_p, final;
49 struct dst_entry *dst;
50 struct flowi6 fl6;
51 struct ip6_flowlabel *flowlabel = NULL;
52 struct ipv6_txoptions *opt;
53 int addr_type;
54 int err;
55
56 if (usin->sin6_family == AF_INET) {
57 if (__ipv6_only_sock(sk))
58 return -EAFNOSUPPORT;
59 err = ip4_datagram_connect(sk, uaddr, addr_len);
60 goto ipv4_connected;
61 }
62
63 if (addr_len < SIN6_LEN_RFC2133)
64 return -EINVAL;
65
66 if (usin->sin6_family != AF_INET6)
67 return -EAFNOSUPPORT;
68
69 memset(&fl6, 0, sizeof(fl6));
70 if (np->sndflow) {
71 fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
72 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
73 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
74 if (flowlabel == NULL)
75 return -EINVAL;
76 usin->sin6_addr = flowlabel->dst;
77 }
78 }
79
80 addr_type = ipv6_addr_type(&usin->sin6_addr);
81
82 if (addr_type == IPV6_ADDR_ANY) {
83 /*
84 * connect to self
85 */
86 usin->sin6_addr.s6_addr[15] = 0x01;
87 }
88
89 daddr = &usin->sin6_addr;
90
91 if (addr_type == IPV6_ADDR_MAPPED) {
92 struct sockaddr_in sin;
93
94 if (__ipv6_only_sock(sk)) {
95 err = -ENETUNREACH;
96 goto out;
97 }
98 sin.sin_family = AF_INET;
99 sin.sin_addr.s_addr = daddr->s6_addr32[3];
100 sin.sin_port = usin->sin6_port;
101
102 err = ip4_datagram_connect(sk,
103 (struct sockaddr *) &sin,
104 sizeof(sin));
105
106 ipv4_connected:
107 if (err)
108 goto out;
109
110 ipv6_addr_set_v4mapped(inet->inet_daddr, &np->daddr);
111
112 if (ipv6_addr_any(&np->saddr) ||
113 ipv6_mapped_addr_any(&np->saddr))
114 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
115
116 if (ipv6_addr_any(&np->rcv_saddr) ||
117 ipv6_mapped_addr_any(&np->rcv_saddr)) {
118 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
119 &np->rcv_saddr);
120 if (sk->sk_prot->rehash)
121 sk->sk_prot->rehash(sk);
122 }
123
124 goto out;
125 }
126
127 if (__ipv6_addr_needs_scope_id(addr_type)) {
128 if (addr_len >= sizeof(struct sockaddr_in6) &&
129 usin->sin6_scope_id) {
130 if (sk->sk_bound_dev_if &&
131 sk->sk_bound_dev_if != usin->sin6_scope_id) {
132 err = -EINVAL;
133 goto out;
134 }
135 sk->sk_bound_dev_if = usin->sin6_scope_id;
136 }
137
138 if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
139 sk->sk_bound_dev_if = np->mcast_oif;
140
141 /* Connect to link-local address requires an interface */
142 if (!sk->sk_bound_dev_if) {
143 err = -EINVAL;
144 goto out;
145 }
146 }
147
148 np->daddr = *daddr;
149 np->flow_label = fl6.flowlabel;
150
151 inet->inet_dport = usin->sin6_port;
152
153 /*
154 * Check for a route to destination an obtain the
155 * destination cache for it.
156 */
157
158 fl6.flowi6_proto = sk->sk_protocol;
159 fl6.daddr = np->daddr;
160 fl6.saddr = np->saddr;
161 fl6.flowi6_oif = sk->sk_bound_dev_if;
162 fl6.flowi6_mark = sk->sk_mark;
163 fl6.fl6_dport = inet->inet_dport;
164 fl6.fl6_sport = inet->inet_sport;
165 fl6.flowi6_uid = sk->sk_uid;
166
167 if (!fl6.flowi6_oif && (addr_type&IPV6_ADDR_MULTICAST))
168 fl6.flowi6_oif = np->mcast_oif;
169
170 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
171
172 rcu_read_lock();
173 opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
174 final_p = fl6_update_dst(&fl6, opt, &final);
175 rcu_read_unlock();
176
177 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
178 err = 0;
179 if (IS_ERR(dst)) {
180 err = PTR_ERR(dst);
181 goto out;
182 }
183
184 /* source address lookup done in ip6_dst_lookup */
185
186 if (ipv6_addr_any(&np->saddr))
187 np->saddr = fl6.saddr;
188
189 if (ipv6_addr_any(&np->rcv_saddr)) {
190 np->rcv_saddr = fl6.saddr;
191 inet->inet_rcv_saddr = LOOPBACK4_IPV6;
192 if (sk->sk_prot->rehash)
193 sk->sk_prot->rehash(sk);
194 }
195
196 ip6_dst_store(sk, dst,
197 ipv6_addr_equal(&fl6.daddr, &np->daddr) ?
198 &np->daddr : NULL,
199 #ifdef CONFIG_IPV6_SUBTREES
200 ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
201 &np->saddr :
202 #endif
203 NULL);
204
205 sk->sk_state = TCP_ESTABLISHED;
206 out:
207 fl6_sock_release(flowlabel);
208 return err;
209 }
210 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
211
ipv6_icmp_error(struct sock * sk,struct sk_buff * skb,int err,__be16 port,u32 info,u8 * payload)212 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
213 __be16 port, u32 info, u8 *payload)
214 {
215 struct ipv6_pinfo *np = inet6_sk(sk);
216 struct icmp6hdr *icmph = icmp6_hdr(skb);
217 struct sock_exterr_skb *serr;
218
219 if (!np->recverr)
220 return;
221
222 skb = skb_clone(skb, GFP_ATOMIC);
223 if (!skb)
224 return;
225
226 skb->protocol = htons(ETH_P_IPV6);
227
228 serr = SKB_EXT_ERR(skb);
229 serr->ee.ee_errno = err;
230 serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
231 serr->ee.ee_type = icmph->icmp6_type;
232 serr->ee.ee_code = icmph->icmp6_code;
233 serr->ee.ee_pad = 0;
234 serr->ee.ee_info = info;
235 serr->ee.ee_data = 0;
236 serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
237 skb_network_header(skb);
238 serr->port = port;
239
240 __skb_pull(skb, payload - skb->data);
241 skb_reset_transport_header(skb);
242
243 if (sock_queue_err_skb(sk, skb))
244 kfree_skb(skb);
245 }
246
ipv6_local_error(struct sock * sk,int err,struct flowi6 * fl6,u32 info)247 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
248 {
249 struct ipv6_pinfo *np = inet6_sk(sk);
250 struct sock_exterr_skb *serr;
251 struct ipv6hdr *iph;
252 struct sk_buff *skb;
253
254 if (!np->recverr)
255 return;
256
257 skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
258 if (!skb)
259 return;
260
261 skb->protocol = htons(ETH_P_IPV6);
262
263 skb_put(skb, sizeof(struct ipv6hdr));
264 skb_reset_network_header(skb);
265 iph = ipv6_hdr(skb);
266 iph->daddr = fl6->daddr;
267
268 serr = SKB_EXT_ERR(skb);
269 serr->ee.ee_errno = err;
270 serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
271 serr->ee.ee_type = 0;
272 serr->ee.ee_code = 0;
273 serr->ee.ee_pad = 0;
274 serr->ee.ee_info = info;
275 serr->ee.ee_data = 0;
276 serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
277 serr->port = fl6->fl6_dport;
278
279 __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
280 skb_reset_transport_header(skb);
281
282 if (sock_queue_err_skb(sk, skb))
283 kfree_skb(skb);
284 }
285
ipv6_local_rxpmtu(struct sock * sk,struct flowi6 * fl6,u32 mtu)286 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
287 {
288 struct ipv6_pinfo *np = inet6_sk(sk);
289 struct ipv6hdr *iph;
290 struct sk_buff *skb;
291 struct ip6_mtuinfo *mtu_info;
292
293 if (!np->rxopt.bits.rxpmtu)
294 return;
295
296 skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
297 if (!skb)
298 return;
299
300 skb_put(skb, sizeof(struct ipv6hdr));
301 skb_reset_network_header(skb);
302 iph = ipv6_hdr(skb);
303 iph->daddr = fl6->daddr;
304
305 mtu_info = IP6CBMTU(skb);
306
307 mtu_info->ip6m_mtu = mtu;
308 mtu_info->ip6m_addr.sin6_family = AF_INET6;
309 mtu_info->ip6m_addr.sin6_port = 0;
310 mtu_info->ip6m_addr.sin6_flowinfo = 0;
311 mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
312 mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
313
314 __skb_pull(skb, skb_tail_pointer(skb) - skb->data);
315 skb_reset_transport_header(skb);
316
317 skb = xchg(&np->rxpmtu, skb);
318 kfree_skb(skb);
319 }
320
321 /*
322 * Handle MSG_ERRQUEUE
323 */
ipv6_recv_error(struct sock * sk,struct msghdr * msg,int len,int * addr_len)324 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
325 {
326 struct ipv6_pinfo *np = inet6_sk(sk);
327 struct sock_exterr_skb *serr;
328 struct sk_buff *skb, *skb2;
329 struct sockaddr_in6 *sin;
330 struct {
331 struct sock_extended_err ee;
332 struct sockaddr_in6 offender;
333 } errhdr;
334 int err;
335 int copied;
336
337 err = -EAGAIN;
338 skb = skb_dequeue(&sk->sk_error_queue);
339 if (skb == NULL)
340 goto out;
341
342 copied = skb->len;
343 if (copied > len) {
344 msg->msg_flags |= MSG_TRUNC;
345 copied = len;
346 }
347 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
348 if (err)
349 goto out_free_skb;
350
351 sock_recv_timestamp(msg, sk, skb);
352
353 serr = SKB_EXT_ERR(skb);
354
355 sin = (struct sockaddr_in6 *)msg->msg_name;
356 if (sin) {
357 const unsigned char *nh = skb_network_header(skb);
358 sin->sin6_family = AF_INET6;
359 sin->sin6_flowinfo = 0;
360 sin->sin6_port = serr->port;
361 if (skb->protocol == htons(ETH_P_IPV6)) {
362 const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
363 struct ipv6hdr, daddr);
364 sin->sin6_addr = ip6h->daddr;
365 if (np->sndflow)
366 sin->sin6_flowinfo = ip6_flowinfo(ip6h);
367 sin->sin6_scope_id =
368 ipv6_iface_scope_id(&sin->sin6_addr,
369 IP6CB(skb)->iif);
370 } else {
371 ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
372 &sin->sin6_addr);
373 sin->sin6_scope_id = 0;
374 }
375 *addr_len = sizeof(*sin);
376 }
377
378 memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
379 sin = &errhdr.offender;
380 sin->sin6_family = AF_UNSPEC;
381 if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
382 sin->sin6_family = AF_INET6;
383 sin->sin6_flowinfo = 0;
384 if (skb->protocol == htons(ETH_P_IPV6)) {
385 sin->sin6_addr = ipv6_hdr(skb)->saddr;
386 if (np->rxopt.all)
387 ip6_datagram_recv_ctl(sk, msg, skb);
388 sin->sin6_scope_id =
389 ipv6_iface_scope_id(&sin->sin6_addr,
390 IP6CB(skb)->iif);
391 } else {
392 struct inet_sock *inet = inet_sk(sk);
393
394 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
395 &sin->sin6_addr);
396 sin->sin6_scope_id = 0;
397 if (inet->cmsg_flags)
398 ip_cmsg_recv(msg, skb);
399 }
400 }
401
402 put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
403
404 /* Now we could try to dump offended packet options */
405
406 msg->msg_flags |= MSG_ERRQUEUE;
407 err = copied;
408
409 /* Reset and regenerate socket error */
410 spin_lock_bh(&sk->sk_error_queue.lock);
411 sk->sk_err = 0;
412 if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
413 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
414 spin_unlock_bh(&sk->sk_error_queue.lock);
415 sk->sk_error_report(sk);
416 } else {
417 spin_unlock_bh(&sk->sk_error_queue.lock);
418 }
419
420 out_free_skb:
421 kfree_skb(skb);
422 out:
423 return err;
424 }
425 EXPORT_SYMBOL_GPL(ipv6_recv_error);
426
427 /*
428 * Handle IPV6_RECVPATHMTU
429 */
ipv6_recv_rxpmtu(struct sock * sk,struct msghdr * msg,int len,int * addr_len)430 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
431 int *addr_len)
432 {
433 struct ipv6_pinfo *np = inet6_sk(sk);
434 struct sk_buff *skb;
435 struct sockaddr_in6 *sin;
436 struct ip6_mtuinfo mtu_info;
437 int err;
438 int copied;
439
440 err = -EAGAIN;
441 skb = xchg(&np->rxpmtu, NULL);
442 if (skb == NULL)
443 goto out;
444
445 copied = skb->len;
446 if (copied > len) {
447 msg->msg_flags |= MSG_TRUNC;
448 copied = len;
449 }
450 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
451 if (err)
452 goto out_free_skb;
453
454 sock_recv_timestamp(msg, sk, skb);
455
456 memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
457
458 sin = (struct sockaddr_in6 *)msg->msg_name;
459 if (sin) {
460 sin->sin6_family = AF_INET6;
461 sin->sin6_flowinfo = 0;
462 sin->sin6_port = 0;
463 sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
464 sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
465 *addr_len = sizeof(*sin);
466 }
467
468 put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
469
470 err = copied;
471
472 out_free_skb:
473 kfree_skb(skb);
474 out:
475 return err;
476 }
477
478
ip6_datagram_recv_ctl(struct sock * sk,struct msghdr * msg,struct sk_buff * skb)479 int ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
480 struct sk_buff *skb)
481 {
482 struct ipv6_pinfo *np = inet6_sk(sk);
483 struct inet6_skb_parm *opt = IP6CB(skb);
484 unsigned char *nh = skb_network_header(skb);
485
486 if (np->rxopt.bits.rxinfo) {
487 struct in6_pktinfo src_info;
488
489 src_info.ipi6_ifindex = opt->iif;
490 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
491 put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
492 }
493
494 if (np->rxopt.bits.rxhlim) {
495 int hlim = ipv6_hdr(skb)->hop_limit;
496 put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
497 }
498
499 if (np->rxopt.bits.rxtclass) {
500 int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
501 put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
502 }
503
504 if (np->rxopt.bits.rxflow) {
505 __be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
506 if (flowinfo)
507 put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
508 }
509
510 /* HbH is allowed only once */
511 if (np->rxopt.bits.hopopts && opt->hop) {
512 u8 *ptr = nh + opt->hop;
513 put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
514 }
515
516 if (opt->lastopt &&
517 (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
518 /*
519 * Silly enough, but we need to reparse in order to
520 * report extension headers (except for HbH)
521 * in order.
522 *
523 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
524 * (and WILL NOT be) defined because
525 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
526 */
527 unsigned int off = sizeof(struct ipv6hdr);
528 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
529
530 while (off <= opt->lastopt) {
531 unsigned int len;
532 u8 *ptr = nh + off;
533
534 switch (nexthdr) {
535 case IPPROTO_DSTOPTS:
536 nexthdr = ptr[0];
537 len = (ptr[1] + 1) << 3;
538 if (np->rxopt.bits.dstopts)
539 put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
540 break;
541 case IPPROTO_ROUTING:
542 nexthdr = ptr[0];
543 len = (ptr[1] + 1) << 3;
544 if (np->rxopt.bits.srcrt)
545 put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
546 break;
547 case IPPROTO_AH:
548 nexthdr = ptr[0];
549 len = (ptr[1] + 2) << 2;
550 break;
551 default:
552 nexthdr = ptr[0];
553 len = (ptr[1] + 1) << 3;
554 break;
555 }
556
557 off += len;
558 }
559 }
560
561 /* socket options in old style */
562 if (np->rxopt.bits.rxoinfo) {
563 struct in6_pktinfo src_info;
564
565 src_info.ipi6_ifindex = opt->iif;
566 src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
567 put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
568 }
569 if (np->rxopt.bits.rxohlim) {
570 int hlim = ipv6_hdr(skb)->hop_limit;
571 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
572 }
573 if (np->rxopt.bits.ohopopts && opt->hop) {
574 u8 *ptr = nh + opt->hop;
575 put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
576 }
577 if (np->rxopt.bits.odstopts && opt->dst0) {
578 u8 *ptr = nh + opt->dst0;
579 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
580 }
581 if (np->rxopt.bits.osrcrt && opt->srcrt) {
582 struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
583 put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
584 }
585 if (np->rxopt.bits.odstopts && opt->dst1) {
586 u8 *ptr = nh + opt->dst1;
587 put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
588 }
589 if (np->rxopt.bits.rxorigdstaddr) {
590 struct sockaddr_in6 sin6;
591 __be16 *ports = (__be16 *) skb_transport_header(skb);
592
593 if (skb_transport_offset(skb) + 4 <= skb->len) {
594 /* All current transport protocols have the port numbers in the
595 * first four bytes of the transport header and this function is
596 * written with this assumption in mind.
597 */
598
599 sin6.sin6_family = AF_INET6;
600 sin6.sin6_addr = ipv6_hdr(skb)->daddr;
601 sin6.sin6_port = ports[1];
602 sin6.sin6_flowinfo = 0;
603 sin6.sin6_scope_id =
604 ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
605 opt->iif);
606
607 put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
608 }
609 }
610 return 0;
611 }
612 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
613
ip6_datagram_send_ctl(struct net * net,struct sock * sk,struct msghdr * msg,struct flowi6 * fl6,struct ipv6_txoptions * opt,int * hlimit,int * tclass,int * dontfrag)614 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
615 struct msghdr *msg, struct flowi6 *fl6,
616 struct ipv6_txoptions *opt,
617 int *hlimit, int *tclass, int *dontfrag)
618 {
619 struct in6_pktinfo *src_info;
620 struct cmsghdr *cmsg;
621 struct ipv6_rt_hdr *rthdr;
622 struct ipv6_opt_hdr *hdr;
623 int len;
624 int err = 0;
625
626 for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
627 int addr_type;
628
629 if (!CMSG_OK(msg, cmsg)) {
630 err = -EINVAL;
631 goto exit_f;
632 }
633
634 if (cmsg->cmsg_level != SOL_IPV6)
635 continue;
636
637 switch (cmsg->cmsg_type) {
638 case IPV6_PKTINFO:
639 case IPV6_2292PKTINFO:
640 {
641 struct net_device *dev = NULL;
642
643 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
644 err = -EINVAL;
645 goto exit_f;
646 }
647
648 src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
649
650 if (src_info->ipi6_ifindex) {
651 if (fl6->flowi6_oif &&
652 src_info->ipi6_ifindex != fl6->flowi6_oif)
653 return -EINVAL;
654 fl6->flowi6_oif = src_info->ipi6_ifindex;
655 }
656
657 addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
658
659 rcu_read_lock();
660 if (fl6->flowi6_oif) {
661 dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
662 if (!dev) {
663 rcu_read_unlock();
664 return -ENODEV;
665 }
666 } else if (addr_type & IPV6_ADDR_LINKLOCAL) {
667 rcu_read_unlock();
668 return -EINVAL;
669 }
670
671 if (addr_type != IPV6_ADDR_ANY) {
672 int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
673 if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
674 !ipv6_chk_addr(net, &src_info->ipi6_addr,
675 strict ? dev : NULL, 0))
676 err = -EINVAL;
677 else
678 fl6->saddr = src_info->ipi6_addr;
679 }
680
681 rcu_read_unlock();
682
683 if (err)
684 goto exit_f;
685
686 break;
687 }
688
689 case IPV6_FLOWINFO:
690 if (cmsg->cmsg_len < CMSG_LEN(4)) {
691 err = -EINVAL;
692 goto exit_f;
693 }
694
695 if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
696 if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
697 err = -EINVAL;
698 goto exit_f;
699 }
700 }
701 fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
702 break;
703
704 case IPV6_2292HOPOPTS:
705 case IPV6_HOPOPTS:
706 if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
707 err = -EINVAL;
708 goto exit_f;
709 }
710
711 hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
712 len = ((hdr->hdrlen + 1) << 3);
713 if (cmsg->cmsg_len < CMSG_LEN(len)) {
714 err = -EINVAL;
715 goto exit_f;
716 }
717 if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
718 err = -EPERM;
719 goto exit_f;
720 }
721 opt->opt_nflen += len;
722 opt->hopopt = hdr;
723 break;
724
725 case IPV6_2292DSTOPTS:
726 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
727 err = -EINVAL;
728 goto exit_f;
729 }
730
731 hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
732 len = ((hdr->hdrlen + 1) << 3);
733 if (cmsg->cmsg_len < CMSG_LEN(len)) {
734 err = -EINVAL;
735 goto exit_f;
736 }
737 if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
738 err = -EPERM;
739 goto exit_f;
740 }
741 if (opt->dst1opt) {
742 err = -EINVAL;
743 goto exit_f;
744 }
745 opt->opt_flen += len;
746 opt->dst1opt = hdr;
747 break;
748
749 case IPV6_DSTOPTS:
750 case IPV6_RTHDRDSTOPTS:
751 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
752 err = -EINVAL;
753 goto exit_f;
754 }
755
756 hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
757 len = ((hdr->hdrlen + 1) << 3);
758 if (cmsg->cmsg_len < CMSG_LEN(len)) {
759 err = -EINVAL;
760 goto exit_f;
761 }
762 if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
763 err = -EPERM;
764 goto exit_f;
765 }
766 if (cmsg->cmsg_type == IPV6_DSTOPTS) {
767 opt->opt_flen += len;
768 opt->dst1opt = hdr;
769 } else {
770 opt->opt_nflen += len;
771 opt->dst0opt = hdr;
772 }
773 break;
774
775 case IPV6_2292RTHDR:
776 case IPV6_RTHDR:
777 if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
778 err = -EINVAL;
779 goto exit_f;
780 }
781
782 rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
783
784 switch (rthdr->type) {
785 #if IS_ENABLED(CONFIG_IPV6_MIP6)
786 case IPV6_SRCRT_TYPE_2:
787 if (rthdr->hdrlen != 2 ||
788 rthdr->segments_left != 1) {
789 err = -EINVAL;
790 goto exit_f;
791 }
792 break;
793 #endif
794 default:
795 err = -EINVAL;
796 goto exit_f;
797 }
798
799 len = ((rthdr->hdrlen + 1) << 3);
800
801 if (cmsg->cmsg_len < CMSG_LEN(len)) {
802 err = -EINVAL;
803 goto exit_f;
804 }
805
806 /* segments left must also match */
807 if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
808 err = -EINVAL;
809 goto exit_f;
810 }
811
812 opt->opt_nflen += len;
813 opt->srcrt = rthdr;
814
815 if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
816 int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
817
818 opt->opt_nflen += dsthdrlen;
819 opt->dst0opt = opt->dst1opt;
820 opt->dst1opt = NULL;
821 opt->opt_flen -= dsthdrlen;
822 }
823
824 break;
825
826 case IPV6_2292HOPLIMIT:
827 case IPV6_HOPLIMIT:
828 if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
829 err = -EINVAL;
830 goto exit_f;
831 }
832
833 *hlimit = *(int *)CMSG_DATA(cmsg);
834 if (*hlimit < -1 || *hlimit > 0xff) {
835 err = -EINVAL;
836 goto exit_f;
837 }
838
839 break;
840
841 case IPV6_TCLASS:
842 {
843 int tc;
844
845 err = -EINVAL;
846 if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
847 goto exit_f;
848
849 tc = *(int *)CMSG_DATA(cmsg);
850 if (tc < -1 || tc > 0xff)
851 goto exit_f;
852
853 err = 0;
854 *tclass = tc;
855
856 break;
857 }
858
859 case IPV6_DONTFRAG:
860 {
861 int df;
862
863 err = -EINVAL;
864 if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
865 goto exit_f;
866
867 df = *(int *)CMSG_DATA(cmsg);
868 if (df < 0 || df > 1)
869 goto exit_f;
870
871 err = 0;
872 *dontfrag = df;
873
874 break;
875 }
876 default:
877 LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
878 cmsg->cmsg_type);
879 err = -EINVAL;
880 goto exit_f;
881 }
882 }
883
884 exit_f:
885 return err;
886 }
887 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
888