xref: /linux/net/ipv6/datagram.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
1 /*
2  *	common UDP/RAW code
3  *	Linux INET6 implementation
4  *
5  *	Authors:
6  *	Pedro Roque		<roque@di.fc.ul.pt>
7  *
8  *	$Id: datagram.c,v 1.24 2002/02/01 22:01:04 davem Exp $
9  *
10  *	This program is free software; you can redistribute it and/or
11  *      modify it under the terms of the GNU General Public License
12  *      as published by the Free Software Foundation; either version
13  *      2 of the License, or (at your option) any later version.
14  */
15 
16 #include <linux/capability.h>
17 #include <linux/errno.h>
18 #include <linux/types.h>
19 #include <linux/kernel.h>
20 #include <linux/interrupt.h>
21 #include <linux/socket.h>
22 #include <linux/sockios.h>
23 #include <linux/in6.h>
24 #include <linux/ipv6.h>
25 #include <linux/route.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 
34 #include <linux/errqueue.h>
35 #include <asm/uaccess.h>
36 
37 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
38 {
39 	struct sockaddr_in6	*usin = (struct sockaddr_in6 *) uaddr;
40 	struct inet_sock      	*inet = inet_sk(sk);
41 	struct ipv6_pinfo      	*np = inet6_sk(sk);
42 	struct in6_addr		*daddr, *final_p = NULL, final;
43 	struct dst_entry	*dst;
44 	struct flowi		fl;
45 	struct ip6_flowlabel	*flowlabel = NULL;
46 	int			addr_type;
47 	int			err;
48 
49 	if (usin->sin6_family == AF_INET) {
50 		if (__ipv6_only_sock(sk))
51 			return -EAFNOSUPPORT;
52 		err = ip4_datagram_connect(sk, uaddr, addr_len);
53 		goto ipv4_connected;
54 	}
55 
56 	if (addr_len < SIN6_LEN_RFC2133)
57 		return -EINVAL;
58 
59 	if (usin->sin6_family != AF_INET6)
60 		return -EAFNOSUPPORT;
61 
62 	memset(&fl, 0, sizeof(fl));
63 	if (np->sndflow) {
64 		fl.fl6_flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
65 		if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
66 			flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
67 			if (flowlabel == NULL)
68 				return -EINVAL;
69 			ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
70 		}
71 	}
72 
73 	addr_type = ipv6_addr_type(&usin->sin6_addr);
74 
75 	if (addr_type == IPV6_ADDR_ANY) {
76 		/*
77 		 *	connect to self
78 		 */
79 		usin->sin6_addr.s6_addr[15] = 0x01;
80 	}
81 
82 	daddr = &usin->sin6_addr;
83 
84 	if (addr_type == IPV6_ADDR_MAPPED) {
85 		struct sockaddr_in sin;
86 
87 		if (__ipv6_only_sock(sk)) {
88 			err = -ENETUNREACH;
89 			goto out;
90 		}
91 		sin.sin_family = AF_INET;
92 		sin.sin_addr.s_addr = daddr->s6_addr32[3];
93 		sin.sin_port = usin->sin6_port;
94 
95 		err = ip4_datagram_connect(sk,
96 					   (struct sockaddr*) &sin,
97 					   sizeof(sin));
98 
99 ipv4_connected:
100 		if (err)
101 			goto out;
102 
103 		ipv6_addr_set(&np->daddr, 0, 0, htonl(0x0000ffff), inet->daddr);
104 
105 		if (ipv6_addr_any(&np->saddr)) {
106 			ipv6_addr_set(&np->saddr, 0, 0, htonl(0x0000ffff),
107 				      inet->saddr);
108 		}
109 
110 		if (ipv6_addr_any(&np->rcv_saddr)) {
111 			ipv6_addr_set(&np->rcv_saddr, 0, 0, htonl(0x0000ffff),
112 				      inet->rcv_saddr);
113 		}
114 		goto out;
115 	}
116 
117 	if (addr_type&IPV6_ADDR_LINKLOCAL) {
118 		if (addr_len >= sizeof(struct sockaddr_in6) &&
119 		    usin->sin6_scope_id) {
120 			if (sk->sk_bound_dev_if &&
121 			    sk->sk_bound_dev_if != usin->sin6_scope_id) {
122 				err = -EINVAL;
123 				goto out;
124 			}
125 			sk->sk_bound_dev_if = usin->sin6_scope_id;
126 			if (!sk->sk_bound_dev_if &&
127 			    (addr_type & IPV6_ADDR_MULTICAST))
128 				fl.oif = np->mcast_oif;
129 		}
130 
131 		/* Connect to link-local address requires an interface */
132 		if (!sk->sk_bound_dev_if) {
133 			err = -EINVAL;
134 			goto out;
135 		}
136 	}
137 
138 	ipv6_addr_copy(&np->daddr, daddr);
139 	np->flow_label = fl.fl6_flowlabel;
140 
141 	inet->dport = usin->sin6_port;
142 
143 	/*
144 	 *	Check for a route to destination an obtain the
145 	 *	destination cache for it.
146 	 */
147 
148 	fl.proto = sk->sk_protocol;
149 	ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
150 	ipv6_addr_copy(&fl.fl6_src, &np->saddr);
151 	fl.oif = sk->sk_bound_dev_if;
152 	fl.fl_ip_dport = inet->dport;
153 	fl.fl_ip_sport = inet->sport;
154 
155 	if (!fl.oif && (addr_type&IPV6_ADDR_MULTICAST))
156 		fl.oif = np->mcast_oif;
157 
158 	security_sk_classify_flow(sk, &fl);
159 
160 	if (flowlabel) {
161 		if (flowlabel->opt && flowlabel->opt->srcrt) {
162 			struct rt0_hdr *rt0 = (struct rt0_hdr *) flowlabel->opt->srcrt;
163 			ipv6_addr_copy(&final, &fl.fl6_dst);
164 			ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
165 			final_p = &final;
166 		}
167 	} else if (np->opt && np->opt->srcrt) {
168 		struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
169 		ipv6_addr_copy(&final, &fl.fl6_dst);
170 		ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
171 		final_p = &final;
172 	}
173 
174 	err = ip6_dst_lookup(sk, &dst, &fl);
175 	if (err)
176 		goto out;
177 	if (final_p)
178 		ipv6_addr_copy(&fl.fl6_dst, final_p);
179 
180 	if ((err = xfrm_lookup(&dst, &fl, sk, 1)) < 0)
181 		goto out;
182 
183 	/* source address lookup done in ip6_dst_lookup */
184 
185 	if (ipv6_addr_any(&np->saddr))
186 		ipv6_addr_copy(&np->saddr, &fl.fl6_src);
187 
188 	if (ipv6_addr_any(&np->rcv_saddr)) {
189 		ipv6_addr_copy(&np->rcv_saddr, &fl.fl6_src);
190 		inet->rcv_saddr = LOOPBACK4_IPV6;
191 	}
192 
193 	ip6_dst_store(sk, dst,
194 		      ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ?
195 		      &np->daddr : NULL,
196 #ifdef CONFIG_IPV6_SUBTREES
197 		      ipv6_addr_equal(&fl.fl6_src, &np->saddr) ?
198 		      &np->saddr :
199 #endif
200 		      NULL);
201 
202 	sk->sk_state = TCP_ESTABLISHED;
203 out:
204 	fl6_sock_release(flowlabel);
205 	return err;
206 }
207 
208 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
209 		     __be16 port, u32 info, u8 *payload)
210 {
211 	struct ipv6_pinfo *np  = inet6_sk(sk);
212 	struct icmp6hdr *icmph = (struct icmp6hdr *)skb->h.raw;
213 	struct sock_exterr_skb *serr;
214 
215 	if (!np->recverr)
216 		return;
217 
218 	skb = skb_clone(skb, GFP_ATOMIC);
219 	if (!skb)
220 		return;
221 
222 	serr = SKB_EXT_ERR(skb);
223 	serr->ee.ee_errno = err;
224 	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
225 	serr->ee.ee_type = icmph->icmp6_type;
226 	serr->ee.ee_code = icmph->icmp6_code;
227 	serr->ee.ee_pad = 0;
228 	serr->ee.ee_info = info;
229 	serr->ee.ee_data = 0;
230 	serr->addr_offset = (u8*)&(((struct ipv6hdr*)(icmph+1))->daddr) - skb->nh.raw;
231 	serr->port = port;
232 
233 	skb->h.raw = payload;
234 	__skb_pull(skb, payload - skb->data);
235 
236 	if (sock_queue_err_skb(sk, skb))
237 		kfree_skb(skb);
238 }
239 
240 void ipv6_local_error(struct sock *sk, int err, struct flowi *fl, u32 info)
241 {
242 	struct ipv6_pinfo *np = inet6_sk(sk);
243 	struct sock_exterr_skb *serr;
244 	struct ipv6hdr *iph;
245 	struct sk_buff *skb;
246 
247 	if (!np->recverr)
248 		return;
249 
250 	skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
251 	if (!skb)
252 		return;
253 
254 	iph = (struct ipv6hdr*)skb_put(skb, sizeof(struct ipv6hdr));
255 	skb->nh.ipv6h = iph;
256 	ipv6_addr_copy(&iph->daddr, &fl->fl6_dst);
257 
258 	serr = SKB_EXT_ERR(skb);
259 	serr->ee.ee_errno = err;
260 	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
261 	serr->ee.ee_type = 0;
262 	serr->ee.ee_code = 0;
263 	serr->ee.ee_pad = 0;
264 	serr->ee.ee_info = info;
265 	serr->ee.ee_data = 0;
266 	serr->addr_offset = (u8*)&iph->daddr - skb->nh.raw;
267 	serr->port = fl->fl_ip_dport;
268 
269 	skb->h.raw = skb->tail;
270 	__skb_pull(skb, skb->tail - skb->data);
271 
272 	if (sock_queue_err_skb(sk, skb))
273 		kfree_skb(skb);
274 }
275 
276 /*
277  *	Handle MSG_ERRQUEUE
278  */
279 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)
280 {
281 	struct ipv6_pinfo *np = inet6_sk(sk);
282 	struct sock_exterr_skb *serr;
283 	struct sk_buff *skb, *skb2;
284 	struct sockaddr_in6 *sin;
285 	struct {
286 		struct sock_extended_err ee;
287 		struct sockaddr_in6	 offender;
288 	} errhdr;
289 	int err;
290 	int copied;
291 
292 	err = -EAGAIN;
293 	skb = skb_dequeue(&sk->sk_error_queue);
294 	if (skb == NULL)
295 		goto out;
296 
297 	copied = skb->len;
298 	if (copied > len) {
299 		msg->msg_flags |= MSG_TRUNC;
300 		copied = len;
301 	}
302 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
303 	if (err)
304 		goto out_free_skb;
305 
306 	sock_recv_timestamp(msg, sk, skb);
307 
308 	serr = SKB_EXT_ERR(skb);
309 
310 	sin = (struct sockaddr_in6 *)msg->msg_name;
311 	if (sin) {
312 		sin->sin6_family = AF_INET6;
313 		sin->sin6_flowinfo = 0;
314 		sin->sin6_port = serr->port;
315 		sin->sin6_scope_id = 0;
316 		if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
317 			ipv6_addr_copy(&sin->sin6_addr,
318 			  (struct in6_addr *)(skb->nh.raw + serr->addr_offset));
319 			if (np->sndflow)
320 				sin->sin6_flowinfo = *(__be32*)(skb->nh.raw + serr->addr_offset - 24) & IPV6_FLOWINFO_MASK;
321 			if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
322 				sin->sin6_scope_id = IP6CB(skb)->iif;
323 		} else {
324 			ipv6_addr_set(&sin->sin6_addr, 0, 0,
325 				      htonl(0xffff),
326 				      *(__be32*)(skb->nh.raw + serr->addr_offset));
327 		}
328 	}
329 
330 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
331 	sin = &errhdr.offender;
332 	sin->sin6_family = AF_UNSPEC;
333 	if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
334 		sin->sin6_family = AF_INET6;
335 		sin->sin6_flowinfo = 0;
336 		sin->sin6_scope_id = 0;
337 		if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
338 			ipv6_addr_copy(&sin->sin6_addr, &skb->nh.ipv6h->saddr);
339 			if (np->rxopt.all)
340 				datagram_recv_ctl(sk, msg, skb);
341 			if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
342 				sin->sin6_scope_id = IP6CB(skb)->iif;
343 		} else {
344 			struct inet_sock *inet = inet_sk(sk);
345 
346 			ipv6_addr_set(&sin->sin6_addr, 0, 0,
347 				      htonl(0xffff),
348 				      skb->nh.iph->saddr);
349 			if (inet->cmsg_flags)
350 				ip_cmsg_recv(msg, skb);
351 		}
352 	}
353 
354 	put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
355 
356 	/* Now we could try to dump offended packet options */
357 
358 	msg->msg_flags |= MSG_ERRQUEUE;
359 	err = copied;
360 
361 	/* Reset and regenerate socket error */
362 	spin_lock_bh(&sk->sk_error_queue.lock);
363 	sk->sk_err = 0;
364 	if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
365 		sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
366 		spin_unlock_bh(&sk->sk_error_queue.lock);
367 		sk->sk_error_report(sk);
368 	} else {
369 		spin_unlock_bh(&sk->sk_error_queue.lock);
370 	}
371 
372 out_free_skb:
373 	kfree_skb(skb);
374 out:
375 	return err;
376 }
377 
378 
379 
380 int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
381 {
382 	struct ipv6_pinfo *np = inet6_sk(sk);
383 	struct inet6_skb_parm *opt = IP6CB(skb);
384 
385 	if (np->rxopt.bits.rxinfo) {
386 		struct in6_pktinfo src_info;
387 
388 		src_info.ipi6_ifindex = opt->iif;
389 		ipv6_addr_copy(&src_info.ipi6_addr, &skb->nh.ipv6h->daddr);
390 		put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
391 	}
392 
393 	if (np->rxopt.bits.rxhlim) {
394 		int hlim = skb->nh.ipv6h->hop_limit;
395 		put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
396 	}
397 
398 	if (np->rxopt.bits.rxtclass) {
399 		int tclass = (ntohl(*(__be32 *)skb->nh.ipv6h) >> 20) & 0xff;
400 		put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
401 	}
402 
403 	if (np->rxopt.bits.rxflow && (*(__be32*)skb->nh.raw & IPV6_FLOWINFO_MASK)) {
404 		__be32 flowinfo = *(__be32*)skb->nh.raw & IPV6_FLOWINFO_MASK;
405 		put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
406 	}
407 
408 	/* HbH is allowed only once */
409 	if (np->rxopt.bits.hopopts && opt->hop) {
410 		u8 *ptr = skb->nh.raw + opt->hop;
411 		put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
412 	}
413 
414 	if (opt->lastopt &&
415 	    (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
416 		/*
417 		 * Silly enough, but we need to reparse in order to
418 		 * report extension headers (except for HbH)
419 		 * in order.
420 		 *
421 		 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
422 		 * (and WILL NOT be) defined because
423 		 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
424 		 */
425 		unsigned int off = sizeof(struct ipv6hdr);
426 		u8 nexthdr = skb->nh.ipv6h->nexthdr;
427 
428 		while (off <= opt->lastopt) {
429 			unsigned len;
430 			u8 *ptr = skb->nh.raw + off;
431 
432 			switch(nexthdr) {
433 			case IPPROTO_DSTOPTS:
434 				nexthdr = ptr[0];
435 				len = (ptr[1] + 1) << 3;
436 				if (np->rxopt.bits.dstopts)
437 					put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
438 				break;
439 			case IPPROTO_ROUTING:
440 				nexthdr = ptr[0];
441 				len = (ptr[1] + 1) << 3;
442 				if (np->rxopt.bits.srcrt)
443 					put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
444 				break;
445 			case IPPROTO_AH:
446 				nexthdr = ptr[0];
447 				len = (ptr[1] + 2) << 2;
448 				break;
449 			default:
450 				nexthdr = ptr[0];
451 				len = (ptr[1] + 1) << 3;
452 				break;
453 			}
454 
455 			off += len;
456 		}
457 	}
458 
459 	/* socket options in old style */
460 	if (np->rxopt.bits.rxoinfo) {
461 		struct in6_pktinfo src_info;
462 
463 		src_info.ipi6_ifindex = opt->iif;
464 		ipv6_addr_copy(&src_info.ipi6_addr, &skb->nh.ipv6h->daddr);
465 		put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
466 	}
467 	if (np->rxopt.bits.rxohlim) {
468 		int hlim = skb->nh.ipv6h->hop_limit;
469 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
470 	}
471 	if (np->rxopt.bits.ohopopts && opt->hop) {
472 		u8 *ptr = skb->nh.raw + opt->hop;
473 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
474 	}
475 	if (np->rxopt.bits.odstopts && opt->dst0) {
476 		u8 *ptr = skb->nh.raw + opt->dst0;
477 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
478 	}
479 	if (np->rxopt.bits.osrcrt && opt->srcrt) {
480 		struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(skb->nh.raw + opt->srcrt);
481 		put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
482 	}
483 	if (np->rxopt.bits.odstopts && opt->dst1) {
484 		u8 *ptr = skb->nh.raw + opt->dst1;
485 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
486 	}
487 	return 0;
488 }
489 
490 int datagram_send_ctl(struct msghdr *msg, struct flowi *fl,
491 		      struct ipv6_txoptions *opt,
492 		      int *hlimit, int *tclass)
493 {
494 	struct in6_pktinfo *src_info;
495 	struct cmsghdr *cmsg;
496 	struct ipv6_rt_hdr *rthdr;
497 	struct ipv6_opt_hdr *hdr;
498 	int len;
499 	int err = 0;
500 
501 	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
502 		int addr_type;
503 		struct net_device *dev = NULL;
504 
505 		if (!CMSG_OK(msg, cmsg)) {
506 			err = -EINVAL;
507 			goto exit_f;
508 		}
509 
510 		if (cmsg->cmsg_level != SOL_IPV6)
511 			continue;
512 
513 		switch (cmsg->cmsg_type) {
514 		case IPV6_PKTINFO:
515 		case IPV6_2292PKTINFO:
516 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
517 				err = -EINVAL;
518 				goto exit_f;
519 			}
520 
521 			src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
522 
523 			if (src_info->ipi6_ifindex) {
524 				if (fl->oif && src_info->ipi6_ifindex != fl->oif)
525 					return -EINVAL;
526 				fl->oif = src_info->ipi6_ifindex;
527 			}
528 
529 			addr_type = ipv6_addr_type(&src_info->ipi6_addr);
530 
531 			if (addr_type == IPV6_ADDR_ANY)
532 				break;
533 
534 			if (addr_type & IPV6_ADDR_LINKLOCAL) {
535 				if (!src_info->ipi6_ifindex)
536 					return -EINVAL;
537 				else {
538 					dev = dev_get_by_index(src_info->ipi6_ifindex);
539 					if (!dev)
540 						return -ENODEV;
541 				}
542 			}
543 			if (!ipv6_chk_addr(&src_info->ipi6_addr, dev, 0)) {
544 				if (dev)
545 					dev_put(dev);
546 				err = -EINVAL;
547 				goto exit_f;
548 			}
549 			if (dev)
550 				dev_put(dev);
551 
552 			ipv6_addr_copy(&fl->fl6_src, &src_info->ipi6_addr);
553 			break;
554 
555 		case IPV6_FLOWINFO:
556 			if (cmsg->cmsg_len < CMSG_LEN(4)) {
557 				err = -EINVAL;
558 				goto exit_f;
559 			}
560 
561 			if (fl->fl6_flowlabel&IPV6_FLOWINFO_MASK) {
562 				if ((fl->fl6_flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
563 					err = -EINVAL;
564 					goto exit_f;
565 				}
566 			}
567 			fl->fl6_flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
568 			break;
569 
570 		case IPV6_2292HOPOPTS:
571 		case IPV6_HOPOPTS:
572 			if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
573 				err = -EINVAL;
574 				goto exit_f;
575 			}
576 
577 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
578 			len = ((hdr->hdrlen + 1) << 3);
579 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
580 				err = -EINVAL;
581 				goto exit_f;
582 			}
583 			if (!capable(CAP_NET_RAW)) {
584 				err = -EPERM;
585 				goto exit_f;
586 			}
587 			opt->opt_nflen += len;
588 			opt->hopopt = hdr;
589 			break;
590 
591 		case IPV6_2292DSTOPTS:
592 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
593 				err = -EINVAL;
594 				goto exit_f;
595 			}
596 
597 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
598 			len = ((hdr->hdrlen + 1) << 3);
599 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
600 				err = -EINVAL;
601 				goto exit_f;
602 			}
603 			if (!capable(CAP_NET_RAW)) {
604 				err = -EPERM;
605 				goto exit_f;
606 			}
607 			if (opt->dst1opt) {
608 				err = -EINVAL;
609 				goto exit_f;
610 			}
611 			opt->opt_flen += len;
612 			opt->dst1opt = hdr;
613 			break;
614 
615 		case IPV6_DSTOPTS:
616 		case IPV6_RTHDRDSTOPTS:
617 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
618 				err = -EINVAL;
619 				goto exit_f;
620 			}
621 
622 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
623 			len = ((hdr->hdrlen + 1) << 3);
624 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
625 				err = -EINVAL;
626 				goto exit_f;
627 			}
628 			if (!capable(CAP_NET_RAW)) {
629 				err = -EPERM;
630 				goto exit_f;
631 			}
632 			if (cmsg->cmsg_type == IPV6_DSTOPTS) {
633 				opt->opt_flen += len;
634 				opt->dst1opt = hdr;
635 			} else {
636 				opt->opt_nflen += len;
637 				opt->dst0opt = hdr;
638 			}
639 			break;
640 
641 		case IPV6_2292RTHDR:
642 		case IPV6_RTHDR:
643 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
644 				err = -EINVAL;
645 				goto exit_f;
646 			}
647 
648 			rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
649 
650 			switch (rthdr->type) {
651 			case IPV6_SRCRT_TYPE_0:
652 #ifdef CONFIG_IPV6_MIP6
653 			case IPV6_SRCRT_TYPE_2:
654 #endif
655 				break;
656 			default:
657 				err = -EINVAL;
658 				goto exit_f;
659 			}
660 
661 			len = ((rthdr->hdrlen + 1) << 3);
662 
663 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
664 				err = -EINVAL;
665 				goto exit_f;
666 			}
667 
668 			/* segments left must also match */
669 			if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
670 				err = -EINVAL;
671 				goto exit_f;
672 			}
673 
674 			opt->opt_nflen += len;
675 			opt->srcrt = rthdr;
676 
677 			if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
678 				int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
679 
680 				opt->opt_nflen += dsthdrlen;
681 				opt->dst0opt = opt->dst1opt;
682 				opt->dst1opt = NULL;
683 				opt->opt_flen -= dsthdrlen;
684 			}
685 
686 			break;
687 
688 		case IPV6_2292HOPLIMIT:
689 		case IPV6_HOPLIMIT:
690 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
691 				err = -EINVAL;
692 				goto exit_f;
693 			}
694 
695 			*hlimit = *(int *)CMSG_DATA(cmsg);
696 			break;
697 
698 		case IPV6_TCLASS:
699 		    {
700 			int tc;
701 
702 			err = -EINVAL;
703 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
704 				goto exit_f;
705 			}
706 
707 			tc = *(int *)CMSG_DATA(cmsg);
708 			if (tc < -1 || tc > 0xff)
709 				goto exit_f;
710 
711 			err = 0;
712 			*tclass = tc;
713 
714 			break;
715 		    }
716 		default:
717 			LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
718 				       cmsg->cmsg_type);
719 			err = -EINVAL;
720 			break;
721 		};
722 	}
723 
724 exit_f:
725 	return err;
726 }
727