xref: /openbmc/linux/net/ipv6/datagram.c (revision f42b3800)
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 		}
127 
128 		if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
129 			sk->sk_bound_dev_if = np->mcast_oif;
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, XFRM_LOOKUP_WAIT)) < 0) {
181 		if (err == -EREMOTE)
182 			err = ip6_dst_blackhole(sk, &dst, &fl);
183 		if (err < 0)
184 			goto out;
185 	}
186 
187 	/* source address lookup done in ip6_dst_lookup */
188 
189 	if (ipv6_addr_any(&np->saddr))
190 		ipv6_addr_copy(&np->saddr, &fl.fl6_src);
191 
192 	if (ipv6_addr_any(&np->rcv_saddr)) {
193 		ipv6_addr_copy(&np->rcv_saddr, &fl.fl6_src);
194 		inet->rcv_saddr = LOOPBACK4_IPV6;
195 	}
196 
197 	ip6_dst_store(sk, dst,
198 		      ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ?
199 		      &np->daddr : NULL,
200 #ifdef CONFIG_IPV6_SUBTREES
201 		      ipv6_addr_equal(&fl.fl6_src, &np->saddr) ?
202 		      &np->saddr :
203 #endif
204 		      NULL);
205 
206 	sk->sk_state = TCP_ESTABLISHED;
207 out:
208 	fl6_sock_release(flowlabel);
209 	return err;
210 }
211 
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 	serr = SKB_EXT_ERR(skb);
227 	serr->ee.ee_errno = err;
228 	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
229 	serr->ee.ee_type = icmph->icmp6_type;
230 	serr->ee.ee_code = icmph->icmp6_code;
231 	serr->ee.ee_pad = 0;
232 	serr->ee.ee_info = info;
233 	serr->ee.ee_data = 0;
234 	serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
235 				  skb_network_header(skb);
236 	serr->port = port;
237 
238 	__skb_pull(skb, payload - skb->data);
239 	skb_reset_transport_header(skb);
240 
241 	if (sock_queue_err_skb(sk, skb))
242 		kfree_skb(skb);
243 }
244 
245 void ipv6_local_error(struct sock *sk, int err, struct flowi *fl, u32 info)
246 {
247 	struct ipv6_pinfo *np = inet6_sk(sk);
248 	struct sock_exterr_skb *serr;
249 	struct ipv6hdr *iph;
250 	struct sk_buff *skb;
251 
252 	if (!np->recverr)
253 		return;
254 
255 	skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
256 	if (!skb)
257 		return;
258 
259 	skb_put(skb, sizeof(struct ipv6hdr));
260 	skb_reset_network_header(skb);
261 	iph = ipv6_hdr(skb);
262 	ipv6_addr_copy(&iph->daddr, &fl->fl6_dst);
263 
264 	serr = SKB_EXT_ERR(skb);
265 	serr->ee.ee_errno = err;
266 	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
267 	serr->ee.ee_type = 0;
268 	serr->ee.ee_code = 0;
269 	serr->ee.ee_pad = 0;
270 	serr->ee.ee_info = info;
271 	serr->ee.ee_data = 0;
272 	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
273 	serr->port = fl->fl_ip_dport;
274 
275 	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
276 	skb_reset_transport_header(skb);
277 
278 	if (sock_queue_err_skb(sk, skb))
279 		kfree_skb(skb);
280 }
281 
282 /*
283  *	Handle MSG_ERRQUEUE
284  */
285 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)
286 {
287 	struct ipv6_pinfo *np = inet6_sk(sk);
288 	struct sock_exterr_skb *serr;
289 	struct sk_buff *skb, *skb2;
290 	struct sockaddr_in6 *sin;
291 	struct {
292 		struct sock_extended_err ee;
293 		struct sockaddr_in6	 offender;
294 	} errhdr;
295 	int err;
296 	int copied;
297 
298 	err = -EAGAIN;
299 	skb = skb_dequeue(&sk->sk_error_queue);
300 	if (skb == NULL)
301 		goto out;
302 
303 	copied = skb->len;
304 	if (copied > len) {
305 		msg->msg_flags |= MSG_TRUNC;
306 		copied = len;
307 	}
308 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
309 	if (err)
310 		goto out_free_skb;
311 
312 	sock_recv_timestamp(msg, sk, skb);
313 
314 	serr = SKB_EXT_ERR(skb);
315 
316 	sin = (struct sockaddr_in6 *)msg->msg_name;
317 	if (sin) {
318 		const unsigned char *nh = skb_network_header(skb);
319 		sin->sin6_family = AF_INET6;
320 		sin->sin6_flowinfo = 0;
321 		sin->sin6_port = serr->port;
322 		sin->sin6_scope_id = 0;
323 		if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
324 			ipv6_addr_copy(&sin->sin6_addr,
325 				  (struct in6_addr *)(nh + serr->addr_offset));
326 			if (np->sndflow)
327 				sin->sin6_flowinfo =
328 					(*(__be32 *)(nh + serr->addr_offset - 24) &
329 					 IPV6_FLOWINFO_MASK);
330 			if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
331 				sin->sin6_scope_id = IP6CB(skb)->iif;
332 		} else {
333 			ipv6_addr_set(&sin->sin6_addr, 0, 0,
334 				      htonl(0xffff),
335 				      *(__be32 *)(nh + serr->addr_offset));
336 		}
337 	}
338 
339 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
340 	sin = &errhdr.offender;
341 	sin->sin6_family = AF_UNSPEC;
342 	if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
343 		sin->sin6_family = AF_INET6;
344 		sin->sin6_flowinfo = 0;
345 		sin->sin6_scope_id = 0;
346 		if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
347 			ipv6_addr_copy(&sin->sin6_addr, &ipv6_hdr(skb)->saddr);
348 			if (np->rxopt.all)
349 				datagram_recv_ctl(sk, msg, skb);
350 			if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
351 				sin->sin6_scope_id = IP6CB(skb)->iif;
352 		} else {
353 			struct inet_sock *inet = inet_sk(sk);
354 
355 			ipv6_addr_set(&sin->sin6_addr, 0, 0,
356 				      htonl(0xffff), ip_hdr(skb)->saddr);
357 			if (inet->cmsg_flags)
358 				ip_cmsg_recv(msg, skb);
359 		}
360 	}
361 
362 	put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
363 
364 	/* Now we could try to dump offended packet options */
365 
366 	msg->msg_flags |= MSG_ERRQUEUE;
367 	err = copied;
368 
369 	/* Reset and regenerate socket error */
370 	spin_lock_bh(&sk->sk_error_queue.lock);
371 	sk->sk_err = 0;
372 	if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
373 		sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
374 		spin_unlock_bh(&sk->sk_error_queue.lock);
375 		sk->sk_error_report(sk);
376 	} else {
377 		spin_unlock_bh(&sk->sk_error_queue.lock);
378 	}
379 
380 out_free_skb:
381 	kfree_skb(skb);
382 out:
383 	return err;
384 }
385 
386 
387 
388 int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
389 {
390 	struct ipv6_pinfo *np = inet6_sk(sk);
391 	struct inet6_skb_parm *opt = IP6CB(skb);
392 	unsigned char *nh = skb_network_header(skb);
393 
394 	if (np->rxopt.bits.rxinfo) {
395 		struct in6_pktinfo src_info;
396 
397 		src_info.ipi6_ifindex = opt->iif;
398 		ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
399 		put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
400 	}
401 
402 	if (np->rxopt.bits.rxhlim) {
403 		int hlim = ipv6_hdr(skb)->hop_limit;
404 		put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
405 	}
406 
407 	if (np->rxopt.bits.rxtclass) {
408 		int tclass = (ntohl(*(__be32 *)ipv6_hdr(skb)) >> 20) & 0xff;
409 		put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
410 	}
411 
412 	if (np->rxopt.bits.rxflow && (*(__be32 *)nh & IPV6_FLOWINFO_MASK)) {
413 		__be32 flowinfo = *(__be32 *)nh & IPV6_FLOWINFO_MASK;
414 		put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
415 	}
416 
417 	/* HbH is allowed only once */
418 	if (np->rxopt.bits.hopopts && opt->hop) {
419 		u8 *ptr = nh + opt->hop;
420 		put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
421 	}
422 
423 	if (opt->lastopt &&
424 	    (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
425 		/*
426 		 * Silly enough, but we need to reparse in order to
427 		 * report extension headers (except for HbH)
428 		 * in order.
429 		 *
430 		 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
431 		 * (and WILL NOT be) defined because
432 		 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
433 		 */
434 		unsigned int off = sizeof(struct ipv6hdr);
435 		u8 nexthdr = ipv6_hdr(skb)->nexthdr;
436 
437 		while (off <= opt->lastopt) {
438 			unsigned len;
439 			u8 *ptr = nh + off;
440 
441 			switch(nexthdr) {
442 			case IPPROTO_DSTOPTS:
443 				nexthdr = ptr[0];
444 				len = (ptr[1] + 1) << 3;
445 				if (np->rxopt.bits.dstopts)
446 					put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
447 				break;
448 			case IPPROTO_ROUTING:
449 				nexthdr = ptr[0];
450 				len = (ptr[1] + 1) << 3;
451 				if (np->rxopt.bits.srcrt)
452 					put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
453 				break;
454 			case IPPROTO_AH:
455 				nexthdr = ptr[0];
456 				len = (ptr[1] + 2) << 2;
457 				break;
458 			default:
459 				nexthdr = ptr[0];
460 				len = (ptr[1] + 1) << 3;
461 				break;
462 			}
463 
464 			off += len;
465 		}
466 	}
467 
468 	/* socket options in old style */
469 	if (np->rxopt.bits.rxoinfo) {
470 		struct in6_pktinfo src_info;
471 
472 		src_info.ipi6_ifindex = opt->iif;
473 		ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
474 		put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
475 	}
476 	if (np->rxopt.bits.rxohlim) {
477 		int hlim = ipv6_hdr(skb)->hop_limit;
478 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
479 	}
480 	if (np->rxopt.bits.ohopopts && opt->hop) {
481 		u8 *ptr = nh + opt->hop;
482 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
483 	}
484 	if (np->rxopt.bits.odstopts && opt->dst0) {
485 		u8 *ptr = nh + opt->dst0;
486 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
487 	}
488 	if (np->rxopt.bits.osrcrt && opt->srcrt) {
489 		struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
490 		put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
491 	}
492 	if (np->rxopt.bits.odstopts && opt->dst1) {
493 		u8 *ptr = nh + opt->dst1;
494 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
495 	}
496 	return 0;
497 }
498 
499 int datagram_send_ctl(struct msghdr *msg, struct flowi *fl,
500 		      struct ipv6_txoptions *opt,
501 		      int *hlimit, int *tclass)
502 {
503 	struct in6_pktinfo *src_info;
504 	struct cmsghdr *cmsg;
505 	struct ipv6_rt_hdr *rthdr;
506 	struct ipv6_opt_hdr *hdr;
507 	int len;
508 	int err = 0;
509 
510 	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
511 		int addr_type;
512 		struct net_device *dev = NULL;
513 
514 		if (!CMSG_OK(msg, cmsg)) {
515 			err = -EINVAL;
516 			goto exit_f;
517 		}
518 
519 		if (cmsg->cmsg_level != SOL_IPV6)
520 			continue;
521 
522 		switch (cmsg->cmsg_type) {
523 		case IPV6_PKTINFO:
524 		case IPV6_2292PKTINFO:
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 			if (addr_type == IPV6_ADDR_ANY)
541 				break;
542 
543 			if (addr_type & IPV6_ADDR_LINKLOCAL) {
544 				if (!src_info->ipi6_ifindex)
545 					return -EINVAL;
546 				else {
547 					dev = dev_get_by_index(&init_net, src_info->ipi6_ifindex);
548 					if (!dev)
549 						return -ENODEV;
550 				}
551 			}
552 			if (!ipv6_chk_addr(&init_net, &src_info->ipi6_addr,
553 					   dev, 0)) {
554 				if (dev)
555 					dev_put(dev);
556 				err = -EINVAL;
557 				goto exit_f;
558 			}
559 			if (dev)
560 				dev_put(dev);
561 
562 			ipv6_addr_copy(&fl->fl6_src, &src_info->ipi6_addr);
563 			break;
564 
565 		case IPV6_FLOWINFO:
566 			if (cmsg->cmsg_len < CMSG_LEN(4)) {
567 				err = -EINVAL;
568 				goto exit_f;
569 			}
570 
571 			if (fl->fl6_flowlabel&IPV6_FLOWINFO_MASK) {
572 				if ((fl->fl6_flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
573 					err = -EINVAL;
574 					goto exit_f;
575 				}
576 			}
577 			fl->fl6_flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
578 			break;
579 
580 		case IPV6_2292HOPOPTS:
581 		case IPV6_HOPOPTS:
582 			if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
583 				err = -EINVAL;
584 				goto exit_f;
585 			}
586 
587 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
588 			len = ((hdr->hdrlen + 1) << 3);
589 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
590 				err = -EINVAL;
591 				goto exit_f;
592 			}
593 			if (!capable(CAP_NET_RAW)) {
594 				err = -EPERM;
595 				goto exit_f;
596 			}
597 			opt->opt_nflen += len;
598 			opt->hopopt = hdr;
599 			break;
600 
601 		case IPV6_2292DSTOPTS:
602 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
603 				err = -EINVAL;
604 				goto exit_f;
605 			}
606 
607 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
608 			len = ((hdr->hdrlen + 1) << 3);
609 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
610 				err = -EINVAL;
611 				goto exit_f;
612 			}
613 			if (!capable(CAP_NET_RAW)) {
614 				err = -EPERM;
615 				goto exit_f;
616 			}
617 			if (opt->dst1opt) {
618 				err = -EINVAL;
619 				goto exit_f;
620 			}
621 			opt->opt_flen += len;
622 			opt->dst1opt = hdr;
623 			break;
624 
625 		case IPV6_DSTOPTS:
626 		case IPV6_RTHDRDSTOPTS:
627 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
628 				err = -EINVAL;
629 				goto exit_f;
630 			}
631 
632 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
633 			len = ((hdr->hdrlen + 1) << 3);
634 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
635 				err = -EINVAL;
636 				goto exit_f;
637 			}
638 			if (!capable(CAP_NET_RAW)) {
639 				err = -EPERM;
640 				goto exit_f;
641 			}
642 			if (cmsg->cmsg_type == IPV6_DSTOPTS) {
643 				opt->opt_flen += len;
644 				opt->dst1opt = hdr;
645 			} else {
646 				opt->opt_nflen += len;
647 				opt->dst0opt = hdr;
648 			}
649 			break;
650 
651 		case IPV6_2292RTHDR:
652 		case IPV6_RTHDR:
653 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
654 				err = -EINVAL;
655 				goto exit_f;
656 			}
657 
658 			rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
659 
660 			switch (rthdr->type) {
661 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
662 			case IPV6_SRCRT_TYPE_2:
663 				break;
664 #endif
665 			default:
666 				err = -EINVAL;
667 				goto exit_f;
668 			}
669 
670 			len = ((rthdr->hdrlen + 1) << 3);
671 
672 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
673 				err = -EINVAL;
674 				goto exit_f;
675 			}
676 
677 			/* segments left must also match */
678 			if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
679 				err = -EINVAL;
680 				goto exit_f;
681 			}
682 
683 			opt->opt_nflen += len;
684 			opt->srcrt = rthdr;
685 
686 			if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
687 				int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
688 
689 				opt->opt_nflen += dsthdrlen;
690 				opt->dst0opt = opt->dst1opt;
691 				opt->dst1opt = NULL;
692 				opt->opt_flen -= dsthdrlen;
693 			}
694 
695 			break;
696 
697 		case IPV6_2292HOPLIMIT:
698 		case IPV6_HOPLIMIT:
699 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
700 				err = -EINVAL;
701 				goto exit_f;
702 			}
703 
704 			*hlimit = *(int *)CMSG_DATA(cmsg);
705 			break;
706 
707 		case IPV6_TCLASS:
708 		    {
709 			int tc;
710 
711 			err = -EINVAL;
712 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
713 				goto exit_f;
714 			}
715 
716 			tc = *(int *)CMSG_DATA(cmsg);
717 			if (tc < -1 || tc > 0xff)
718 				goto exit_f;
719 
720 			err = 0;
721 			*tclass = tc;
722 
723 			break;
724 		    }
725 		default:
726 			LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
727 				       cmsg->cmsg_type);
728 			err = -EINVAL;
729 			break;
730 		}
731 	}
732 
733 exit_f:
734 	return err;
735 }
736