xref: /linux/net/ipv6/datagram.c (revision 606d099cdd1080bbb50ea50dc52d98252f8f10a1)
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/sched.h>
21 #include <linux/interrupt.h>
22 #include <linux/socket.h>
23 #include <linux/sockios.h>
24 #include <linux/in6.h>
25 #include <linux/ipv6.h>
26 #include <linux/route.h>
27 
28 #include <net/ipv6.h>
29 #include <net/ndisc.h>
30 #include <net/addrconf.h>
31 #include <net/transp_v6.h>
32 #include <net/ip6_route.h>
33 #include <net/tcp_states.h>
34 
35 #include <linux/errqueue.h>
36 #include <asm/uaccess.h>
37 
38 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
39 {
40 	struct sockaddr_in6	*usin = (struct sockaddr_in6 *) uaddr;
41 	struct inet_sock      	*inet = inet_sk(sk);
42 	struct ipv6_pinfo      	*np = inet6_sk(sk);
43 	struct in6_addr		*daddr, *final_p = NULL, final;
44 	struct dst_entry	*dst;
45 	struct flowi		fl;
46 	struct ip6_flowlabel	*flowlabel = NULL;
47 	int			addr_type;
48 	int			err;
49 
50 	if (usin->sin6_family == AF_INET) {
51 		if (__ipv6_only_sock(sk))
52 			return -EAFNOSUPPORT;
53 		err = ip4_datagram_connect(sk, uaddr, addr_len);
54 		goto ipv4_connected;
55 	}
56 
57 	if (addr_len < SIN6_LEN_RFC2133)
58 	  	return -EINVAL;
59 
60 	if (usin->sin6_family != AF_INET6)
61 	  	return -EAFNOSUPPORT;
62 
63 	memset(&fl, 0, sizeof(fl));
64 	if (np->sndflow) {
65 		fl.fl6_flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
66 		if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
67 			flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
68 			if (flowlabel == NULL)
69 				return -EINVAL;
70 			ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
71 		}
72 	}
73 
74 	addr_type = ipv6_addr_type(&usin->sin6_addr);
75 
76 	if (addr_type == IPV6_ADDR_ANY) {
77 		/*
78 		 *	connect to self
79 		 */
80 		usin->sin6_addr.s6_addr[15] = 0x01;
81 	}
82 
83 	daddr = &usin->sin6_addr;
84 
85 	if (addr_type == IPV6_ADDR_MAPPED) {
86 		struct sockaddr_in sin;
87 
88 		if (__ipv6_only_sock(sk)) {
89 			err = -ENETUNREACH;
90 			goto out;
91 		}
92 		sin.sin_family = AF_INET;
93 		sin.sin_addr.s_addr = daddr->s6_addr32[3];
94 		sin.sin_port = usin->sin6_port;
95 
96 		err = ip4_datagram_connect(sk,
97 					   (struct sockaddr*) &sin,
98 					   sizeof(sin));
99 
100 ipv4_connected:
101 		if (err)
102 			goto out;
103 
104 		ipv6_addr_set(&np->daddr, 0, 0, htonl(0x0000ffff), inet->daddr);
105 
106 		if (ipv6_addr_any(&np->saddr)) {
107 			ipv6_addr_set(&np->saddr, 0, 0, htonl(0x0000ffff),
108 				      inet->saddr);
109 		}
110 
111 		if (ipv6_addr_any(&np->rcv_saddr)) {
112 			ipv6_addr_set(&np->rcv_saddr, 0, 0, htonl(0x0000ffff),
113 				      inet->rcv_saddr);
114 		}
115 		goto out;
116 	}
117 
118 	if (addr_type&IPV6_ADDR_LINKLOCAL) {
119 		if (addr_len >= sizeof(struct sockaddr_in6) &&
120 		    usin->sin6_scope_id) {
121 			if (sk->sk_bound_dev_if &&
122 			    sk->sk_bound_dev_if != usin->sin6_scope_id) {
123 				err = -EINVAL;
124 				goto out;
125 			}
126 			sk->sk_bound_dev_if = usin->sin6_scope_id;
127 			if (!sk->sk_bound_dev_if &&
128 			    (addr_type & IPV6_ADDR_MULTICAST))
129 				fl.oif = np->mcast_oif;
130 		}
131 
132 		/* Connect to link-local address requires an interface */
133 		if (!sk->sk_bound_dev_if) {
134 			err = -EINVAL;
135 			goto out;
136 		}
137 	}
138 
139 	ipv6_addr_copy(&np->daddr, daddr);
140 	np->flow_label = fl.fl6_flowlabel;
141 
142 	inet->dport = usin->sin6_port;
143 
144 	/*
145 	 *	Check for a route to destination an obtain the
146 	 *	destination cache for it.
147 	 */
148 
149 	fl.proto = sk->sk_protocol;
150 	ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
151 	ipv6_addr_copy(&fl.fl6_src, &np->saddr);
152 	fl.oif = sk->sk_bound_dev_if;
153 	fl.fl_ip_dport = inet->dport;
154 	fl.fl_ip_sport = inet->sport;
155 
156 	if (!fl.oif && (addr_type&IPV6_ADDR_MULTICAST))
157 		fl.oif = np->mcast_oif;
158 
159 	security_sk_classify_flow(sk, &fl);
160 
161 	if (flowlabel) {
162 		if (flowlabel->opt && flowlabel->opt->srcrt) {
163 			struct rt0_hdr *rt0 = (struct rt0_hdr *) flowlabel->opt->srcrt;
164 			ipv6_addr_copy(&final, &fl.fl6_dst);
165 			ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
166 			final_p = &final;
167 		}
168 	} else if (np->opt && np->opt->srcrt) {
169 		struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
170 		ipv6_addr_copy(&final, &fl.fl6_dst);
171 		ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
172 		final_p = &final;
173 	}
174 
175 	err = ip6_dst_lookup(sk, &dst, &fl);
176 	if (err)
177 		goto out;
178 	if (final_p)
179 		ipv6_addr_copy(&fl.fl6_dst, final_p);
180 
181 	if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0)
182 		goto out;
183 
184 	/* source address lookup done in ip6_dst_lookup */
185 
186 	if (ipv6_addr_any(&np->saddr))
187 		ipv6_addr_copy(&np->saddr, &fl.fl6_src);
188 
189 	if (ipv6_addr_any(&np->rcv_saddr)) {
190 		ipv6_addr_copy(&np->rcv_saddr, &fl.fl6_src);
191 		inet->rcv_saddr = LOOPBACK4_IPV6;
192 	}
193 
194 	ip6_dst_store(sk, dst,
195 		      ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ?
196 		      &np->daddr : NULL,
197 #ifdef CONFIG_IPV6_SUBTREES
198 		      ipv6_addr_equal(&fl.fl6_src, &np->saddr) ?
199 		      &np->saddr :
200 #endif
201 		      NULL);
202 
203 	sk->sk_state = TCP_ESTABLISHED;
204 out:
205 	fl6_sock_release(flowlabel);
206 	return err;
207 }
208 
209 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
210 		     __be16 port, u32 info, u8 *payload)
211 {
212 	struct ipv6_pinfo *np  = inet6_sk(sk);
213 	struct icmp6hdr *icmph = (struct icmp6hdr *)skb->h.raw;
214 	struct sock_exterr_skb *serr;
215 
216 	if (!np->recverr)
217 		return;
218 
219 	skb = skb_clone(skb, GFP_ATOMIC);
220 	if (!skb)
221 		return;
222 
223 	serr = SKB_EXT_ERR(skb);
224 	serr->ee.ee_errno = err;
225 	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
226 	serr->ee.ee_type = icmph->icmp6_type;
227 	serr->ee.ee_code = icmph->icmp6_code;
228 	serr->ee.ee_pad = 0;
229 	serr->ee.ee_info = info;
230 	serr->ee.ee_data = 0;
231 	serr->addr_offset = (u8*)&(((struct ipv6hdr*)(icmph+1))->daddr) - skb->nh.raw;
232 	serr->port = port;
233 
234 	skb->h.raw = payload;
235 	__skb_pull(skb, payload - skb->data);
236 
237 	if (sock_queue_err_skb(sk, skb))
238 		kfree_skb(skb);
239 }
240 
241 void ipv6_local_error(struct sock *sk, int err, struct flowi *fl, u32 info)
242 {
243 	struct ipv6_pinfo *np = inet6_sk(sk);
244 	struct sock_exterr_skb *serr;
245 	struct ipv6hdr *iph;
246 	struct sk_buff *skb;
247 
248 	if (!np->recverr)
249 		return;
250 
251 	skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
252 	if (!skb)
253 		return;
254 
255 	iph = (struct ipv6hdr*)skb_put(skb, sizeof(struct ipv6hdr));
256 	skb->nh.ipv6h = iph;
257 	ipv6_addr_copy(&iph->daddr, &fl->fl6_dst);
258 
259 	serr = SKB_EXT_ERR(skb);
260 	serr->ee.ee_errno = err;
261 	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
262 	serr->ee.ee_type = 0;
263 	serr->ee.ee_code = 0;
264 	serr->ee.ee_pad = 0;
265 	serr->ee.ee_info = info;
266 	serr->ee.ee_data = 0;
267 	serr->addr_offset = (u8*)&iph->daddr - skb->nh.raw;
268 	serr->port = fl->fl_ip_dport;
269 
270 	skb->h.raw = skb->tail;
271 	__skb_pull(skb, skb->tail - skb->data);
272 
273 	if (sock_queue_err_skb(sk, skb))
274 		kfree_skb(skb);
275 }
276 
277 /*
278  *	Handle MSG_ERRQUEUE
279  */
280 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)
281 {
282 	struct ipv6_pinfo *np = inet6_sk(sk);
283 	struct sock_exterr_skb *serr;
284 	struct sk_buff *skb, *skb2;
285 	struct sockaddr_in6 *sin;
286 	struct {
287 		struct sock_extended_err ee;
288 		struct sockaddr_in6	 offender;
289 	} errhdr;
290 	int err;
291 	int copied;
292 
293 	err = -EAGAIN;
294 	skb = skb_dequeue(&sk->sk_error_queue);
295 	if (skb == NULL)
296 		goto out;
297 
298 	copied = skb->len;
299 	if (copied > len) {
300 		msg->msg_flags |= MSG_TRUNC;
301 		copied = len;
302 	}
303 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
304 	if (err)
305 		goto out_free_skb;
306 
307 	sock_recv_timestamp(msg, sk, skb);
308 
309 	serr = SKB_EXT_ERR(skb);
310 
311 	sin = (struct sockaddr_in6 *)msg->msg_name;
312 	if (sin) {
313 		sin->sin6_family = AF_INET6;
314 		sin->sin6_flowinfo = 0;
315 		sin->sin6_port = serr->port;
316 		sin->sin6_scope_id = 0;
317 		if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
318 			ipv6_addr_copy(&sin->sin6_addr,
319 			  (struct in6_addr *)(skb->nh.raw + serr->addr_offset));
320 			if (np->sndflow)
321 				sin->sin6_flowinfo = *(__be32*)(skb->nh.raw + serr->addr_offset - 24) & IPV6_FLOWINFO_MASK;
322 			if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
323 				sin->sin6_scope_id = IP6CB(skb)->iif;
324 		} else {
325 			ipv6_addr_set(&sin->sin6_addr, 0, 0,
326 				      htonl(0xffff),
327 				      *(__be32*)(skb->nh.raw + serr->addr_offset));
328 		}
329 	}
330 
331 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
332 	sin = &errhdr.offender;
333 	sin->sin6_family = AF_UNSPEC;
334 	if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
335 		sin->sin6_family = AF_INET6;
336 		sin->sin6_flowinfo = 0;
337 		sin->sin6_scope_id = 0;
338 		if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
339 			ipv6_addr_copy(&sin->sin6_addr, &skb->nh.ipv6h->saddr);
340 			if (np->rxopt.all)
341 				datagram_recv_ctl(sk, msg, skb);
342 			if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
343 				sin->sin6_scope_id = IP6CB(skb)->iif;
344 		} else {
345 			struct inet_sock *inet = inet_sk(sk);
346 
347 			ipv6_addr_set(&sin->sin6_addr, 0, 0,
348 				      htonl(0xffff),
349 				      skb->nh.iph->saddr);
350 			if (inet->cmsg_flags)
351 				ip_cmsg_recv(msg, skb);
352 		}
353 	}
354 
355 	put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
356 
357 	/* Now we could try to dump offended packet options */
358 
359 	msg->msg_flags |= MSG_ERRQUEUE;
360 	err = copied;
361 
362 	/* Reset and regenerate socket error */
363 	spin_lock_bh(&sk->sk_error_queue.lock);
364 	sk->sk_err = 0;
365 	if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
366 		sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
367 		spin_unlock_bh(&sk->sk_error_queue.lock);
368 		sk->sk_error_report(sk);
369 	} else {
370 		spin_unlock_bh(&sk->sk_error_queue.lock);
371 	}
372 
373 out_free_skb:
374 	kfree_skb(skb);
375 out:
376 	return err;
377 }
378 
379 
380 
381 int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
382 {
383 	struct ipv6_pinfo *np = inet6_sk(sk);
384 	struct inet6_skb_parm *opt = IP6CB(skb);
385 
386 	if (np->rxopt.bits.rxinfo) {
387 		struct in6_pktinfo src_info;
388 
389 		src_info.ipi6_ifindex = opt->iif;
390 		ipv6_addr_copy(&src_info.ipi6_addr, &skb->nh.ipv6h->daddr);
391 		put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
392 	}
393 
394 	if (np->rxopt.bits.rxhlim) {
395 		int hlim = skb->nh.ipv6h->hop_limit;
396 		put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
397 	}
398 
399 	if (np->rxopt.bits.rxtclass) {
400 		int tclass = (ntohl(*(__be32 *)skb->nh.ipv6h) >> 20) & 0xff;
401 		put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
402 	}
403 
404 	if (np->rxopt.bits.rxflow && (*(__be32*)skb->nh.raw & IPV6_FLOWINFO_MASK)) {
405 		__be32 flowinfo = *(__be32*)skb->nh.raw & IPV6_FLOWINFO_MASK;
406 		put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
407 	}
408 
409 	/* HbH is allowed only once */
410 	if (np->rxopt.bits.hopopts && opt->hop) {
411 		u8 *ptr = skb->nh.raw + opt->hop;
412 		put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
413 	}
414 
415 	if (opt->lastopt &&
416 	    (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
417 		/*
418 		 * Silly enough, but we need to reparse in order to
419 		 * report extension headers (except for HbH)
420 		 * in order.
421 		 *
422 		 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
423 		 * (and WILL NOT be) defined because
424 		 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
425 		 */
426 		unsigned int off = sizeof(struct ipv6hdr);
427 		u8 nexthdr = skb->nh.ipv6h->nexthdr;
428 
429 		while (off <= opt->lastopt) {
430 			unsigned len;
431 			u8 *ptr = skb->nh.raw + off;
432 
433 			switch(nexthdr) {
434 			case IPPROTO_DSTOPTS:
435 				nexthdr = ptr[0];
436 				len = (ptr[1] + 1) << 3;
437 				if (np->rxopt.bits.dstopts)
438 					put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
439 				break;
440 			case IPPROTO_ROUTING:
441 				nexthdr = ptr[0];
442 				len = (ptr[1] + 1) << 3;
443 				if (np->rxopt.bits.srcrt)
444 					put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
445 				break;
446 			case IPPROTO_AH:
447 				nexthdr = ptr[0];
448 				len = (ptr[1] + 2) << 2;
449 				break;
450 			default:
451 				nexthdr = ptr[0];
452 				len = (ptr[1] + 1) << 3;
453 				break;
454 			}
455 
456 			off += len;
457 		}
458 	}
459 
460 	/* socket options in old style */
461 	if (np->rxopt.bits.rxoinfo) {
462 		struct in6_pktinfo src_info;
463 
464 		src_info.ipi6_ifindex = opt->iif;
465 		ipv6_addr_copy(&src_info.ipi6_addr, &skb->nh.ipv6h->daddr);
466 		put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
467 	}
468 	if (np->rxopt.bits.rxohlim) {
469 		int hlim = skb->nh.ipv6h->hop_limit;
470 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
471 	}
472 	if (np->rxopt.bits.ohopopts && opt->hop) {
473 		u8 *ptr = skb->nh.raw + opt->hop;
474 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
475 	}
476 	if (np->rxopt.bits.odstopts && opt->dst0) {
477 		u8 *ptr = skb->nh.raw + opt->dst0;
478 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
479 	}
480 	if (np->rxopt.bits.osrcrt && opt->srcrt) {
481 		struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(skb->nh.raw + opt->srcrt);
482 		put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
483 	}
484 	if (np->rxopt.bits.odstopts && opt->dst1) {
485 		u8 *ptr = skb->nh.raw + opt->dst1;
486 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
487 	}
488 	return 0;
489 }
490 
491 int datagram_send_ctl(struct msghdr *msg, struct flowi *fl,
492 		      struct ipv6_txoptions *opt,
493 		      int *hlimit, int *tclass)
494 {
495 	struct in6_pktinfo *src_info;
496 	struct cmsghdr *cmsg;
497 	struct ipv6_rt_hdr *rthdr;
498 	struct ipv6_opt_hdr *hdr;
499 	int len;
500 	int err = 0;
501 
502 	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
503 		int addr_type;
504 		struct net_device *dev = NULL;
505 
506 		if (!CMSG_OK(msg, cmsg)) {
507 			err = -EINVAL;
508 			goto exit_f;
509 		}
510 
511 		if (cmsg->cmsg_level != SOL_IPV6)
512 			continue;
513 
514 		switch (cmsg->cmsg_type) {
515  		case IPV6_PKTINFO:
516  		case IPV6_2292PKTINFO:
517  			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
518 				err = -EINVAL;
519 				goto exit_f;
520 			}
521 
522 			src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
523 
524 			if (src_info->ipi6_ifindex) {
525 				if (fl->oif && src_info->ipi6_ifindex != fl->oif)
526 					return -EINVAL;
527 				fl->oif = src_info->ipi6_ifindex;
528 			}
529 
530 			addr_type = ipv6_addr_type(&src_info->ipi6_addr);
531 
532 			if (addr_type == IPV6_ADDR_ANY)
533 				break;
534 
535 			if (addr_type & IPV6_ADDR_LINKLOCAL) {
536 				if (!src_info->ipi6_ifindex)
537 					return -EINVAL;
538 				else {
539 					dev = dev_get_by_index(src_info->ipi6_ifindex);
540 					if (!dev)
541 						return -ENODEV;
542 				}
543 			}
544 			if (!ipv6_chk_addr(&src_info->ipi6_addr, dev, 0)) {
545 				if (dev)
546 					dev_put(dev);
547 				err = -EINVAL;
548 				goto exit_f;
549 			}
550 			if (dev)
551 				dev_put(dev);
552 
553 			ipv6_addr_copy(&fl->fl6_src, &src_info->ipi6_addr);
554 			break;
555 
556 		case IPV6_FLOWINFO:
557                         if (cmsg->cmsg_len < CMSG_LEN(4)) {
558 				err = -EINVAL;
559 				goto exit_f;
560 			}
561 
562 			if (fl->fl6_flowlabel&IPV6_FLOWINFO_MASK) {
563 				if ((fl->fl6_flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
564 					err = -EINVAL;
565 					goto exit_f;
566 				}
567 			}
568 			fl->fl6_flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
569 			break;
570 
571 		case IPV6_2292HOPOPTS:
572 		case IPV6_HOPOPTS:
573                         if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
574 				err = -EINVAL;
575 				goto exit_f;
576 			}
577 
578 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
579 			len = ((hdr->hdrlen + 1) << 3);
580 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
581 				err = -EINVAL;
582 				goto exit_f;
583 			}
584 			if (!capable(CAP_NET_RAW)) {
585 				err = -EPERM;
586 				goto exit_f;
587 			}
588 			opt->opt_nflen += len;
589 			opt->hopopt = hdr;
590 			break;
591 
592 		case IPV6_2292DSTOPTS:
593                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
594 				err = -EINVAL;
595 				goto exit_f;
596 			}
597 
598 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
599 			len = ((hdr->hdrlen + 1) << 3);
600 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
601 				err = -EINVAL;
602 				goto exit_f;
603 			}
604 			if (!capable(CAP_NET_RAW)) {
605 				err = -EPERM;
606 				goto exit_f;
607 			}
608 			if (opt->dst1opt) {
609 				err = -EINVAL;
610 				goto exit_f;
611 			}
612 			opt->opt_flen += len;
613 			opt->dst1opt = hdr;
614 			break;
615 
616 		case IPV6_DSTOPTS:
617 		case IPV6_RTHDRDSTOPTS:
618 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
619 				err = -EINVAL;
620 				goto exit_f;
621 			}
622 
623 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
624 			len = ((hdr->hdrlen + 1) << 3);
625 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
626 				err = -EINVAL;
627 				goto exit_f;
628 			}
629 			if (!capable(CAP_NET_RAW)) {
630 				err = -EPERM;
631 				goto exit_f;
632 			}
633 			if (cmsg->cmsg_type == IPV6_DSTOPTS) {
634 				opt->opt_flen += len;
635 				opt->dst1opt = hdr;
636 			} else {
637 				opt->opt_nflen += len;
638 				opt->dst0opt = hdr;
639 			}
640 			break;
641 
642 		case IPV6_2292RTHDR:
643 		case IPV6_RTHDR:
644                         if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
645 				err = -EINVAL;
646 				goto exit_f;
647 			}
648 
649 			rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
650 
651 			switch (rthdr->type) {
652 			case IPV6_SRCRT_TYPE_0:
653 #ifdef CONFIG_IPV6_MIP6
654 			case IPV6_SRCRT_TYPE_2:
655 #endif
656 				break;
657 			default:
658 				err = -EINVAL;
659 				goto exit_f;
660 			}
661 
662 			len = ((rthdr->hdrlen + 1) << 3);
663 
664                         if (cmsg->cmsg_len < CMSG_LEN(len)) {
665 				err = -EINVAL;
666 				goto exit_f;
667 			}
668 
669 			/* segments left must also match */
670 			if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
671 				err = -EINVAL;
672 				goto exit_f;
673 			}
674 
675 			opt->opt_nflen += len;
676 			opt->srcrt = rthdr;
677 
678 			if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
679 				int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
680 
681 				opt->opt_nflen += dsthdrlen;
682 				opt->dst0opt = opt->dst1opt;
683 				opt->dst1opt = NULL;
684 				opt->opt_flen -= dsthdrlen;
685 			}
686 
687 			break;
688 
689 		case IPV6_2292HOPLIMIT:
690 		case IPV6_HOPLIMIT:
691 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
692 				err = -EINVAL;
693 				goto exit_f;
694 			}
695 
696 			*hlimit = *(int *)CMSG_DATA(cmsg);
697 			break;
698 
699 		case IPV6_TCLASS:
700 		    {
701 			int tc;
702 
703 			err = -EINVAL;
704 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
705 				goto exit_f;
706 			}
707 
708 			tc = *(int *)CMSG_DATA(cmsg);
709 			if (tc < -1 || tc > 0xff)
710 				goto exit_f;
711 
712 			err = 0;
713 			*tclass = tc;
714 
715 			break;
716 		    }
717 		default:
718 			LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
719 			               cmsg->cmsg_type);
720 			err = -EINVAL;
721 			break;
722 		};
723 	}
724 
725 exit_f:
726 	return err;
727 }
728