xref: /linux/net/ipv6/datagram.c (revision e26207a3819684e9b4450a2d30bdd065fa92d9c7)
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 
25 #include <net/ipv6.h>
26 #include <net/ndisc.h>
27 #include <net/addrconf.h>
28 #include <net/transp_v6.h>
29 #include <net/ip6_route.h>
30 #include <net/tcp_states.h>
31 
32 #include <linux/errqueue.h>
33 #include <asm/uaccess.h>
34 
35 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
36 {
37 	struct sockaddr_in6	*usin = (struct sockaddr_in6 *) uaddr;
38 	struct inet_sock      	*inet = inet_sk(sk);
39 	struct ipv6_pinfo      	*np = inet6_sk(sk);
40 	struct in6_addr		*daddr, *final_p = NULL, final;
41 	struct dst_entry	*dst;
42 	struct flowi		fl;
43 	struct ip6_flowlabel	*flowlabel = NULL;
44 	int			addr_type;
45 	int			err;
46 
47 	if (usin->sin6_family == AF_INET) {
48 		if (__ipv6_only_sock(sk))
49 			return -EAFNOSUPPORT;
50 		err = ip4_datagram_connect(sk, uaddr, addr_len);
51 		goto ipv4_connected;
52 	}
53 
54 	if (addr_len < SIN6_LEN_RFC2133)
55 		return -EINVAL;
56 
57 	if (usin->sin6_family != AF_INET6)
58 		return -EAFNOSUPPORT;
59 
60 	memset(&fl, 0, sizeof(fl));
61 	if (np->sndflow) {
62 		fl.fl6_flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
63 		if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
64 			flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
65 			if (flowlabel == NULL)
66 				return -EINVAL;
67 			ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
68 		}
69 	}
70 
71 	addr_type = ipv6_addr_type(&usin->sin6_addr);
72 
73 	if (addr_type == IPV6_ADDR_ANY) {
74 		/*
75 		 *	connect to self
76 		 */
77 		usin->sin6_addr.s6_addr[15] = 0x01;
78 	}
79 
80 	daddr = &usin->sin6_addr;
81 
82 	if (addr_type == IPV6_ADDR_MAPPED) {
83 		struct sockaddr_in sin;
84 
85 		if (__ipv6_only_sock(sk)) {
86 			err = -ENETUNREACH;
87 			goto out;
88 		}
89 		sin.sin_family = AF_INET;
90 		sin.sin_addr.s_addr = daddr->s6_addr32[3];
91 		sin.sin_port = usin->sin6_port;
92 
93 		err = ip4_datagram_connect(sk,
94 					   (struct sockaddr*) &sin,
95 					   sizeof(sin));
96 
97 ipv4_connected:
98 		if (err)
99 			goto out;
100 
101 		ipv6_addr_set_v4mapped(inet->inet_daddr, &np->daddr);
102 
103 		if (ipv6_addr_any(&np->saddr))
104 			ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
105 
106 		if (ipv6_addr_any(&np->rcv_saddr))
107 			ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
108 					       &np->rcv_saddr);
109 
110 		goto out;
111 	}
112 
113 	if (addr_type&IPV6_ADDR_LINKLOCAL) {
114 		if (addr_len >= sizeof(struct sockaddr_in6) &&
115 		    usin->sin6_scope_id) {
116 			if (sk->sk_bound_dev_if &&
117 			    sk->sk_bound_dev_if != usin->sin6_scope_id) {
118 				err = -EINVAL;
119 				goto out;
120 			}
121 			sk->sk_bound_dev_if = usin->sin6_scope_id;
122 		}
123 
124 		if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
125 			sk->sk_bound_dev_if = np->mcast_oif;
126 
127 		/* Connect to link-local address requires an interface */
128 		if (!sk->sk_bound_dev_if) {
129 			err = -EINVAL;
130 			goto out;
131 		}
132 	}
133 
134 	ipv6_addr_copy(&np->daddr, daddr);
135 	np->flow_label = fl.fl6_flowlabel;
136 
137 	inet->inet_dport = usin->sin6_port;
138 
139 	/*
140 	 *	Check for a route to destination an obtain the
141 	 *	destination cache for it.
142 	 */
143 
144 	fl.proto = sk->sk_protocol;
145 	ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
146 	ipv6_addr_copy(&fl.fl6_src, &np->saddr);
147 	fl.oif = sk->sk_bound_dev_if;
148 	fl.mark = sk->sk_mark;
149 	fl.fl_ip_dport = inet->inet_dport;
150 	fl.fl_ip_sport = inet->inet_sport;
151 
152 	if (!fl.oif && (addr_type&IPV6_ADDR_MULTICAST))
153 		fl.oif = np->mcast_oif;
154 
155 	security_sk_classify_flow(sk, &fl);
156 
157 	if (flowlabel) {
158 		if (flowlabel->opt && flowlabel->opt->srcrt) {
159 			struct rt0_hdr *rt0 = (struct rt0_hdr *) flowlabel->opt->srcrt;
160 			ipv6_addr_copy(&final, &fl.fl6_dst);
161 			ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
162 			final_p = &final;
163 		}
164 	} else if (np->opt && np->opt->srcrt) {
165 		struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
166 		ipv6_addr_copy(&final, &fl.fl6_dst);
167 		ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
168 		final_p = &final;
169 	}
170 
171 	err = ip6_dst_lookup(sk, &dst, &fl);
172 	if (err)
173 		goto out;
174 	if (final_p)
175 		ipv6_addr_copy(&fl.fl6_dst, final_p);
176 
177 	err = __xfrm_lookup(sock_net(sk), &dst, &fl, sk, XFRM_LOOKUP_WAIT);
178 	if (err < 0) {
179 		if (err == -EREMOTE)
180 			err = ip6_dst_blackhole(sk, &dst, &fl);
181 		if (err < 0)
182 			goto out;
183 	}
184 
185 	/* source address lookup done in ip6_dst_lookup */
186 
187 	if (ipv6_addr_any(&np->saddr))
188 		ipv6_addr_copy(&np->saddr, &fl.fl6_src);
189 
190 	if (ipv6_addr_any(&np->rcv_saddr)) {
191 		ipv6_addr_copy(&np->rcv_saddr, &fl.fl6_src);
192 		inet->inet_rcv_saddr = LOOPBACK4_IPV6;
193 	}
194 
195 	ip6_dst_store(sk, dst,
196 		      ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ?
197 		      &np->daddr : NULL,
198 #ifdef CONFIG_IPV6_SUBTREES
199 		      ipv6_addr_equal(&fl.fl6_src, &np->saddr) ?
200 		      &np->saddr :
201 #endif
202 		      NULL);
203 
204 	sk->sk_state = TCP_ESTABLISHED;
205 out:
206 	fl6_sock_release(flowlabel);
207 	return err;
208 }
209 
210 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
211 		     __be16 port, u32 info, u8 *payload)
212 {
213 	struct ipv6_pinfo *np  = inet6_sk(sk);
214 	struct icmp6hdr *icmph = icmp6_hdr(skb);
215 	struct sock_exterr_skb *serr;
216 
217 	if (!np->recverr)
218 		return;
219 
220 	skb = skb_clone(skb, GFP_ATOMIC);
221 	if (!skb)
222 		return;
223 
224 	serr = SKB_EXT_ERR(skb);
225 	serr->ee.ee_errno = err;
226 	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
227 	serr->ee.ee_type = icmph->icmp6_type;
228 	serr->ee.ee_code = icmph->icmp6_code;
229 	serr->ee.ee_pad = 0;
230 	serr->ee.ee_info = info;
231 	serr->ee.ee_data = 0;
232 	serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
233 				  skb_network_header(skb);
234 	serr->port = port;
235 
236 	__skb_pull(skb, payload - skb->data);
237 	skb_reset_transport_header(skb);
238 
239 	if (sock_queue_err_skb(sk, skb))
240 		kfree_skb(skb);
241 }
242 
243 void ipv6_local_error(struct sock *sk, int err, struct flowi *fl, u32 info)
244 {
245 	struct ipv6_pinfo *np = inet6_sk(sk);
246 	struct sock_exterr_skb *serr;
247 	struct ipv6hdr *iph;
248 	struct sk_buff *skb;
249 
250 	if (!np->recverr)
251 		return;
252 
253 	skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
254 	if (!skb)
255 		return;
256 
257 	skb_put(skb, sizeof(struct ipv6hdr));
258 	skb_reset_network_header(skb);
259 	iph = ipv6_hdr(skb);
260 	ipv6_addr_copy(&iph->daddr, &fl->fl6_dst);
261 
262 	serr = SKB_EXT_ERR(skb);
263 	serr->ee.ee_errno = err;
264 	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
265 	serr->ee.ee_type = 0;
266 	serr->ee.ee_code = 0;
267 	serr->ee.ee_pad = 0;
268 	serr->ee.ee_info = info;
269 	serr->ee.ee_data = 0;
270 	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
271 	serr->port = fl->fl_ip_dport;
272 
273 	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
274 	skb_reset_transport_header(skb);
275 
276 	if (sock_queue_err_skb(sk, skb))
277 		kfree_skb(skb);
278 }
279 
280 /*
281  *	Handle MSG_ERRQUEUE
282  */
283 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)
284 {
285 	struct ipv6_pinfo *np = inet6_sk(sk);
286 	struct sock_exterr_skb *serr;
287 	struct sk_buff *skb, *skb2;
288 	struct sockaddr_in6 *sin;
289 	struct {
290 		struct sock_extended_err ee;
291 		struct sockaddr_in6	 offender;
292 	} errhdr;
293 	int err;
294 	int copied;
295 
296 	err = -EAGAIN;
297 	skb = skb_dequeue(&sk->sk_error_queue);
298 	if (skb == NULL)
299 		goto out;
300 
301 	copied = skb->len;
302 	if (copied > len) {
303 		msg->msg_flags |= MSG_TRUNC;
304 		copied = len;
305 	}
306 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
307 	if (err)
308 		goto out_free_skb;
309 
310 	sock_recv_timestamp(msg, sk, skb);
311 
312 	serr = SKB_EXT_ERR(skb);
313 
314 	sin = (struct sockaddr_in6 *)msg->msg_name;
315 	if (sin) {
316 		const unsigned char *nh = skb_network_header(skb);
317 		sin->sin6_family = AF_INET6;
318 		sin->sin6_flowinfo = 0;
319 		sin->sin6_port = serr->port;
320 		sin->sin6_scope_id = 0;
321 		if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
322 			ipv6_addr_copy(&sin->sin6_addr,
323 				  (struct in6_addr *)(nh + serr->addr_offset));
324 			if (np->sndflow)
325 				sin->sin6_flowinfo =
326 					(*(__be32 *)(nh + serr->addr_offset - 24) &
327 					 IPV6_FLOWINFO_MASK);
328 			if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
329 				sin->sin6_scope_id = IP6CB(skb)->iif;
330 		} else {
331 			ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
332 					       &sin->sin6_addr);
333 		}
334 	}
335 
336 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
337 	sin = &errhdr.offender;
338 	sin->sin6_family = AF_UNSPEC;
339 	if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
340 		sin->sin6_family = AF_INET6;
341 		sin->sin6_flowinfo = 0;
342 		sin->sin6_scope_id = 0;
343 		if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
344 			ipv6_addr_copy(&sin->sin6_addr, &ipv6_hdr(skb)->saddr);
345 			if (np->rxopt.all)
346 				datagram_recv_ctl(sk, msg, skb);
347 			if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
348 				sin->sin6_scope_id = IP6CB(skb)->iif;
349 		} else {
350 			struct inet_sock *inet = inet_sk(sk);
351 
352 			ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
353 					       &sin->sin6_addr);
354 			if (inet->cmsg_flags)
355 				ip_cmsg_recv(msg, skb);
356 		}
357 	}
358 
359 	put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
360 
361 	/* Now we could try to dump offended packet options */
362 
363 	msg->msg_flags |= MSG_ERRQUEUE;
364 	err = copied;
365 
366 	/* Reset and regenerate socket error */
367 	spin_lock_bh(&sk->sk_error_queue.lock);
368 	sk->sk_err = 0;
369 	if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
370 		sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
371 		spin_unlock_bh(&sk->sk_error_queue.lock);
372 		sk->sk_error_report(sk);
373 	} else {
374 		spin_unlock_bh(&sk->sk_error_queue.lock);
375 	}
376 
377 out_free_skb:
378 	kfree_skb(skb);
379 out:
380 	return err;
381 }
382 
383 
384 
385 int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
386 {
387 	struct ipv6_pinfo *np = inet6_sk(sk);
388 	struct inet6_skb_parm *opt = IP6CB(skb);
389 	unsigned char *nh = skb_network_header(skb);
390 
391 	if (np->rxopt.bits.rxinfo) {
392 		struct in6_pktinfo src_info;
393 
394 		src_info.ipi6_ifindex = opt->iif;
395 		ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
396 		put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
397 	}
398 
399 	if (np->rxopt.bits.rxhlim) {
400 		int hlim = ipv6_hdr(skb)->hop_limit;
401 		put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
402 	}
403 
404 	if (np->rxopt.bits.rxtclass) {
405 		int tclass = (ntohl(*(__be32 *)ipv6_hdr(skb)) >> 20) & 0xff;
406 		put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
407 	}
408 
409 	if (np->rxopt.bits.rxflow && (*(__be32 *)nh & IPV6_FLOWINFO_MASK)) {
410 		__be32 flowinfo = *(__be32 *)nh & IPV6_FLOWINFO_MASK;
411 		put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
412 	}
413 
414 	/* HbH is allowed only once */
415 	if (np->rxopt.bits.hopopts && opt->hop) {
416 		u8 *ptr = nh + opt->hop;
417 		put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
418 	}
419 
420 	if (opt->lastopt &&
421 	    (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
422 		/*
423 		 * Silly enough, but we need to reparse in order to
424 		 * report extension headers (except for HbH)
425 		 * in order.
426 		 *
427 		 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
428 		 * (and WILL NOT be) defined because
429 		 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
430 		 */
431 		unsigned int off = sizeof(struct ipv6hdr);
432 		u8 nexthdr = ipv6_hdr(skb)->nexthdr;
433 
434 		while (off <= opt->lastopt) {
435 			unsigned len;
436 			u8 *ptr = nh + off;
437 
438 			switch(nexthdr) {
439 			case IPPROTO_DSTOPTS:
440 				nexthdr = ptr[0];
441 				len = (ptr[1] + 1) << 3;
442 				if (np->rxopt.bits.dstopts)
443 					put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
444 				break;
445 			case IPPROTO_ROUTING:
446 				nexthdr = ptr[0];
447 				len = (ptr[1] + 1) << 3;
448 				if (np->rxopt.bits.srcrt)
449 					put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
450 				break;
451 			case IPPROTO_AH:
452 				nexthdr = ptr[0];
453 				len = (ptr[1] + 2) << 2;
454 				break;
455 			default:
456 				nexthdr = ptr[0];
457 				len = (ptr[1] + 1) << 3;
458 				break;
459 			}
460 
461 			off += len;
462 		}
463 	}
464 
465 	/* socket options in old style */
466 	if (np->rxopt.bits.rxoinfo) {
467 		struct in6_pktinfo src_info;
468 
469 		src_info.ipi6_ifindex = opt->iif;
470 		ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
471 		put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
472 	}
473 	if (np->rxopt.bits.rxohlim) {
474 		int hlim = ipv6_hdr(skb)->hop_limit;
475 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
476 	}
477 	if (np->rxopt.bits.ohopopts && opt->hop) {
478 		u8 *ptr = nh + opt->hop;
479 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
480 	}
481 	if (np->rxopt.bits.odstopts && opt->dst0) {
482 		u8 *ptr = nh + opt->dst0;
483 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
484 	}
485 	if (np->rxopt.bits.osrcrt && opt->srcrt) {
486 		struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
487 		put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
488 	}
489 	if (np->rxopt.bits.odstopts && opt->dst1) {
490 		u8 *ptr = nh + opt->dst1;
491 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
492 	}
493 	return 0;
494 }
495 
496 int datagram_send_ctl(struct net *net,
497 		      struct msghdr *msg, struct flowi *fl,
498 		      struct ipv6_txoptions *opt,
499 		      int *hlimit, int *tclass)
500 {
501 	struct in6_pktinfo *src_info;
502 	struct cmsghdr *cmsg;
503 	struct ipv6_rt_hdr *rthdr;
504 	struct ipv6_opt_hdr *hdr;
505 	int len;
506 	int err = 0;
507 
508 	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
509 		int addr_type;
510 
511 		if (!CMSG_OK(msg, cmsg)) {
512 			err = -EINVAL;
513 			goto exit_f;
514 		}
515 
516 		if (cmsg->cmsg_level != SOL_IPV6)
517 			continue;
518 
519 		switch (cmsg->cmsg_type) {
520 		case IPV6_PKTINFO:
521 		case IPV6_2292PKTINFO:
522 		    {
523 			struct net_device *dev = NULL;
524 
525 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
526 				err = -EINVAL;
527 				goto exit_f;
528 			}
529 
530 			src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
531 
532 			if (src_info->ipi6_ifindex) {
533 				if (fl->oif && src_info->ipi6_ifindex != fl->oif)
534 					return -EINVAL;
535 				fl->oif = src_info->ipi6_ifindex;
536 			}
537 
538 			addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
539 
540 			rcu_read_lock();
541 			if (fl->oif) {
542 				dev = dev_get_by_index_rcu(net, fl->oif);
543 				if (!dev) {
544 					rcu_read_unlock();
545 					return -ENODEV;
546 				}
547 			} else if (addr_type & IPV6_ADDR_LINKLOCAL) {
548 				rcu_read_unlock();
549 				return -EINVAL;
550 			}
551 
552 			if (addr_type != IPV6_ADDR_ANY) {
553 				int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
554 				if (!ipv6_chk_addr(net, &src_info->ipi6_addr,
555 						   strict ? dev : NULL, 0))
556 					err = -EINVAL;
557 				else
558 					ipv6_addr_copy(&fl->fl6_src, &src_info->ipi6_addr);
559 			}
560 
561 			rcu_read_unlock();
562 
563 			if (err)
564 				goto exit_f;
565 
566 			break;
567 		    }
568 
569 		case IPV6_FLOWINFO:
570 			if (cmsg->cmsg_len < CMSG_LEN(4)) {
571 				err = -EINVAL;
572 				goto exit_f;
573 			}
574 
575 			if (fl->fl6_flowlabel&IPV6_FLOWINFO_MASK) {
576 				if ((fl->fl6_flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
577 					err = -EINVAL;
578 					goto exit_f;
579 				}
580 			}
581 			fl->fl6_flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
582 			break;
583 
584 		case IPV6_2292HOPOPTS:
585 		case IPV6_HOPOPTS:
586 			if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
587 				err = -EINVAL;
588 				goto exit_f;
589 			}
590 
591 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
592 			len = ((hdr->hdrlen + 1) << 3);
593 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
594 				err = -EINVAL;
595 				goto exit_f;
596 			}
597 			if (!capable(CAP_NET_RAW)) {
598 				err = -EPERM;
599 				goto exit_f;
600 			}
601 			opt->opt_nflen += len;
602 			opt->hopopt = hdr;
603 			break;
604 
605 		case IPV6_2292DSTOPTS:
606 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
607 				err = -EINVAL;
608 				goto exit_f;
609 			}
610 
611 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
612 			len = ((hdr->hdrlen + 1) << 3);
613 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
614 				err = -EINVAL;
615 				goto exit_f;
616 			}
617 			if (!capable(CAP_NET_RAW)) {
618 				err = -EPERM;
619 				goto exit_f;
620 			}
621 			if (opt->dst1opt) {
622 				err = -EINVAL;
623 				goto exit_f;
624 			}
625 			opt->opt_flen += len;
626 			opt->dst1opt = hdr;
627 			break;
628 
629 		case IPV6_DSTOPTS:
630 		case IPV6_RTHDRDSTOPTS:
631 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
632 				err = -EINVAL;
633 				goto exit_f;
634 			}
635 
636 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
637 			len = ((hdr->hdrlen + 1) << 3);
638 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
639 				err = -EINVAL;
640 				goto exit_f;
641 			}
642 			if (!capable(CAP_NET_RAW)) {
643 				err = -EPERM;
644 				goto exit_f;
645 			}
646 			if (cmsg->cmsg_type == IPV6_DSTOPTS) {
647 				opt->opt_flen += len;
648 				opt->dst1opt = hdr;
649 			} else {
650 				opt->opt_nflen += len;
651 				opt->dst0opt = hdr;
652 			}
653 			break;
654 
655 		case IPV6_2292RTHDR:
656 		case IPV6_RTHDR:
657 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
658 				err = -EINVAL;
659 				goto exit_f;
660 			}
661 
662 			rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
663 
664 			switch (rthdr->type) {
665 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
666 			case IPV6_SRCRT_TYPE_2:
667 				if (rthdr->hdrlen != 2 ||
668 				    rthdr->segments_left != 1) {
669 					err = -EINVAL;
670 					goto exit_f;
671 				}
672 				break;
673 #endif
674 			default:
675 				err = -EINVAL;
676 				goto exit_f;
677 			}
678 
679 			len = ((rthdr->hdrlen + 1) << 3);
680 
681 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
682 				err = -EINVAL;
683 				goto exit_f;
684 			}
685 
686 			/* segments left must also match */
687 			if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
688 				err = -EINVAL;
689 				goto exit_f;
690 			}
691 
692 			opt->opt_nflen += len;
693 			opt->srcrt = rthdr;
694 
695 			if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
696 				int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
697 
698 				opt->opt_nflen += dsthdrlen;
699 				opt->dst0opt = opt->dst1opt;
700 				opt->dst1opt = NULL;
701 				opt->opt_flen -= dsthdrlen;
702 			}
703 
704 			break;
705 
706 		case IPV6_2292HOPLIMIT:
707 		case IPV6_HOPLIMIT:
708 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
709 				err = -EINVAL;
710 				goto exit_f;
711 			}
712 
713 			*hlimit = *(int *)CMSG_DATA(cmsg);
714 			if (*hlimit < -1 || *hlimit > 0xff) {
715 				err = -EINVAL;
716 				goto exit_f;
717 			}
718 
719 			break;
720 
721 		case IPV6_TCLASS:
722 		    {
723 			int tc;
724 
725 			err = -EINVAL;
726 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
727 				goto exit_f;
728 			}
729 
730 			tc = *(int *)CMSG_DATA(cmsg);
731 			if (tc < -1 || tc > 0xff)
732 				goto exit_f;
733 
734 			err = 0;
735 			*tclass = tc;
736 
737 			break;
738 		    }
739 		default:
740 			LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
741 				       cmsg->cmsg_type);
742 			err = -EINVAL;
743 			goto exit_f;
744 		}
745 	}
746 
747 exit_f:
748 	return err;
749 }
750