xref: /linux/net/ipv6/datagram.c (revision c145211d1f9e2ef19e7b4c2b943f68366daa97af)
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 
26 #include <net/ipv6.h>
27 #include <net/ndisc.h>
28 #include <net/addrconf.h>
29 #include <net/transp_v6.h>
30 #include <net/ip6_route.h>
31 #include <net/tcp_states.h>
32 
33 #include <linux/errqueue.h>
34 #include <asm/uaccess.h>
35 
36 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
37 {
38 	struct sockaddr_in6	*usin = (struct sockaddr_in6 *) uaddr;
39 	struct inet_sock      	*inet = inet_sk(sk);
40 	struct ipv6_pinfo      	*np = inet6_sk(sk);
41 	struct in6_addr		*daddr, *final_p = NULL, final;
42 	struct dst_entry	*dst;
43 	struct flowi		fl;
44 	struct ip6_flowlabel	*flowlabel = NULL;
45 	int			addr_type;
46 	int			err;
47 
48 	if (usin->sin6_family == AF_INET) {
49 		if (__ipv6_only_sock(sk))
50 			return -EAFNOSUPPORT;
51 		err = ip4_datagram_connect(sk, uaddr, addr_len);
52 		goto ipv4_connected;
53 	}
54 
55 	if (addr_len < SIN6_LEN_RFC2133)
56 		return -EINVAL;
57 
58 	if (usin->sin6_family != AF_INET6)
59 		return -EAFNOSUPPORT;
60 
61 	memset(&fl, 0, sizeof(fl));
62 	if (np->sndflow) {
63 		fl.fl6_flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
64 		if (fl.fl6_flowlabel&IPV6_FLOWLABEL_MASK) {
65 			flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
66 			if (flowlabel == NULL)
67 				return -EINVAL;
68 			ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
69 		}
70 	}
71 
72 	addr_type = ipv6_addr_type(&usin->sin6_addr);
73 
74 	if (addr_type == IPV6_ADDR_ANY) {
75 		/*
76 		 *	connect to self
77 		 */
78 		usin->sin6_addr.s6_addr[15] = 0x01;
79 	}
80 
81 	daddr = &usin->sin6_addr;
82 
83 	if (addr_type == IPV6_ADDR_MAPPED) {
84 		struct sockaddr_in sin;
85 
86 		if (__ipv6_only_sock(sk)) {
87 			err = -ENETUNREACH;
88 			goto out;
89 		}
90 		sin.sin_family = AF_INET;
91 		sin.sin_addr.s_addr = daddr->s6_addr32[3];
92 		sin.sin_port = usin->sin6_port;
93 
94 		err = ip4_datagram_connect(sk,
95 					   (struct sockaddr*) &sin,
96 					   sizeof(sin));
97 
98 ipv4_connected:
99 		if (err)
100 			goto out;
101 
102 		ipv6_addr_set_v4mapped(inet->inet_daddr, &np->daddr);
103 
104 		if (ipv6_addr_any(&np->saddr))
105 			ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
106 
107 		if (ipv6_addr_any(&np->rcv_saddr))
108 			ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
109 					       &np->rcv_saddr);
110 
111 		goto out;
112 	}
113 
114 	if (addr_type&IPV6_ADDR_LINKLOCAL) {
115 		if (addr_len >= sizeof(struct sockaddr_in6) &&
116 		    usin->sin6_scope_id) {
117 			if (sk->sk_bound_dev_if &&
118 			    sk->sk_bound_dev_if != usin->sin6_scope_id) {
119 				err = -EINVAL;
120 				goto out;
121 			}
122 			sk->sk_bound_dev_if = usin->sin6_scope_id;
123 		}
124 
125 		if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
126 			sk->sk_bound_dev_if = np->mcast_oif;
127 
128 		/* Connect to link-local address requires an interface */
129 		if (!sk->sk_bound_dev_if) {
130 			err = -EINVAL;
131 			goto out;
132 		}
133 	}
134 
135 	ipv6_addr_copy(&np->daddr, daddr);
136 	np->flow_label = fl.fl6_flowlabel;
137 
138 	inet->inet_dport = usin->sin6_port;
139 
140 	/*
141 	 *	Check for a route to destination an obtain the
142 	 *	destination cache for it.
143 	 */
144 
145 	fl.proto = sk->sk_protocol;
146 	ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
147 	ipv6_addr_copy(&fl.fl6_src, &np->saddr);
148 	fl.oif = sk->sk_bound_dev_if;
149 	fl.mark = sk->sk_mark;
150 	fl.fl_ip_dport = inet->inet_dport;
151 	fl.fl_ip_sport = inet->inet_sport;
152 
153 	if (!fl.oif && (addr_type&IPV6_ADDR_MULTICAST))
154 		fl.oif = np->mcast_oif;
155 
156 	security_sk_classify_flow(sk, &fl);
157 
158 	if (flowlabel) {
159 		if (flowlabel->opt && flowlabel->opt->srcrt) {
160 			struct rt0_hdr *rt0 = (struct rt0_hdr *) flowlabel->opt->srcrt;
161 			ipv6_addr_copy(&final, &fl.fl6_dst);
162 			ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
163 			final_p = &final;
164 		}
165 	} else if (np->opt && np->opt->srcrt) {
166 		struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
167 		ipv6_addr_copy(&final, &fl.fl6_dst);
168 		ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
169 		final_p = &final;
170 	}
171 
172 	err = ip6_dst_lookup(sk, &dst, &fl);
173 	if (err)
174 		goto out;
175 	if (final_p)
176 		ipv6_addr_copy(&fl.fl6_dst, final_p);
177 
178 	err = __xfrm_lookup(sock_net(sk), &dst, &fl, sk, XFRM_LOOKUP_WAIT);
179 	if (err < 0) {
180 		if (err == -EREMOTE)
181 			err = ip6_dst_blackhole(sk, &dst, &fl);
182 		if (err < 0)
183 			goto out;
184 	}
185 
186 	/* source address lookup done in ip6_dst_lookup */
187 
188 	if (ipv6_addr_any(&np->saddr))
189 		ipv6_addr_copy(&np->saddr, &fl.fl6_src);
190 
191 	if (ipv6_addr_any(&np->rcv_saddr)) {
192 		ipv6_addr_copy(&np->rcv_saddr, &fl.fl6_src);
193 		inet->inet_rcv_saddr = LOOPBACK4_IPV6;
194 	}
195 
196 	ip6_dst_store(sk, dst,
197 		      ipv6_addr_equal(&fl.fl6_dst, &np->daddr) ?
198 		      &np->daddr : NULL,
199 #ifdef CONFIG_IPV6_SUBTREES
200 		      ipv6_addr_equal(&fl.fl6_src, &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 
211 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
212 		     __be16 port, u32 info, u8 *payload)
213 {
214 	struct ipv6_pinfo *np  = inet6_sk(sk);
215 	struct icmp6hdr *icmph = icmp6_hdr(skb);
216 	struct sock_exterr_skb *serr;
217 
218 	if (!np->recverr)
219 		return;
220 
221 	skb = skb_clone(skb, GFP_ATOMIC);
222 	if (!skb)
223 		return;
224 
225 	skb->protocol = htons(ETH_P_IPV6);
226 
227 	serr = SKB_EXT_ERR(skb);
228 	serr->ee.ee_errno = err;
229 	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
230 	serr->ee.ee_type = icmph->icmp6_type;
231 	serr->ee.ee_code = icmph->icmp6_code;
232 	serr->ee.ee_pad = 0;
233 	serr->ee.ee_info = info;
234 	serr->ee.ee_data = 0;
235 	serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
236 				  skb_network_header(skb);
237 	serr->port = port;
238 
239 	__skb_pull(skb, payload - skb->data);
240 	skb_reset_transport_header(skb);
241 
242 	if (sock_queue_err_skb(sk, skb))
243 		kfree_skb(skb);
244 }
245 
246 void ipv6_local_error(struct sock *sk, int err, struct flowi *fl, u32 info)
247 {
248 	struct ipv6_pinfo *np = inet6_sk(sk);
249 	struct sock_exterr_skb *serr;
250 	struct ipv6hdr *iph;
251 	struct sk_buff *skb;
252 
253 	if (!np->recverr)
254 		return;
255 
256 	skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
257 	if (!skb)
258 		return;
259 
260 	skb->protocol = htons(ETH_P_IPV6);
261 
262 	skb_put(skb, sizeof(struct ipv6hdr));
263 	skb_reset_network_header(skb);
264 	iph = ipv6_hdr(skb);
265 	ipv6_addr_copy(&iph->daddr, &fl->fl6_dst);
266 
267 	serr = SKB_EXT_ERR(skb);
268 	serr->ee.ee_errno = err;
269 	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
270 	serr->ee.ee_type = 0;
271 	serr->ee.ee_code = 0;
272 	serr->ee.ee_pad = 0;
273 	serr->ee.ee_info = info;
274 	serr->ee.ee_data = 0;
275 	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
276 	serr->port = fl->fl_ip_dport;
277 
278 	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
279 	skb_reset_transport_header(skb);
280 
281 	if (sock_queue_err_skb(sk, skb))
282 		kfree_skb(skb);
283 }
284 
285 /*
286  *	Handle MSG_ERRQUEUE
287  */
288 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)
289 {
290 	struct ipv6_pinfo *np = inet6_sk(sk);
291 	struct sock_exterr_skb *serr;
292 	struct sk_buff *skb, *skb2;
293 	struct sockaddr_in6 *sin;
294 	struct {
295 		struct sock_extended_err ee;
296 		struct sockaddr_in6	 offender;
297 	} errhdr;
298 	int err;
299 	int copied;
300 
301 	err = -EAGAIN;
302 	skb = skb_dequeue(&sk->sk_error_queue);
303 	if (skb == NULL)
304 		goto out;
305 
306 	copied = skb->len;
307 	if (copied > len) {
308 		msg->msg_flags |= MSG_TRUNC;
309 		copied = len;
310 	}
311 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
312 	if (err)
313 		goto out_free_skb;
314 
315 	sock_recv_timestamp(msg, sk, skb);
316 
317 	serr = SKB_EXT_ERR(skb);
318 
319 	sin = (struct sockaddr_in6 *)msg->msg_name;
320 	if (sin) {
321 		const unsigned char *nh = skb_network_header(skb);
322 		sin->sin6_family = AF_INET6;
323 		sin->sin6_flowinfo = 0;
324 		sin->sin6_port = serr->port;
325 		sin->sin6_scope_id = 0;
326 		if (skb->protocol == htons(ETH_P_IPV6)) {
327 			ipv6_addr_copy(&sin->sin6_addr,
328 				  (struct in6_addr *)(nh + serr->addr_offset));
329 			if (np->sndflow)
330 				sin->sin6_flowinfo =
331 					(*(__be32 *)(nh + serr->addr_offset - 24) &
332 					 IPV6_FLOWINFO_MASK);
333 			if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
334 				sin->sin6_scope_id = IP6CB(skb)->iif;
335 		} else {
336 			ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
337 					       &sin->sin6_addr);
338 		}
339 	}
340 
341 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
342 	sin = &errhdr.offender;
343 	sin->sin6_family = AF_UNSPEC;
344 	if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
345 		sin->sin6_family = AF_INET6;
346 		sin->sin6_flowinfo = 0;
347 		sin->sin6_scope_id = 0;
348 		if (skb->protocol == htons(ETH_P_IPV6)) {
349 			ipv6_addr_copy(&sin->sin6_addr, &ipv6_hdr(skb)->saddr);
350 			if (np->rxopt.all)
351 				datagram_recv_ctl(sk, msg, skb);
352 			if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
353 				sin->sin6_scope_id = IP6CB(skb)->iif;
354 		} else {
355 			struct inet_sock *inet = inet_sk(sk);
356 
357 			ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
358 					       &sin->sin6_addr);
359 			if (inet->cmsg_flags)
360 				ip_cmsg_recv(msg, skb);
361 		}
362 	}
363 
364 	put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
365 
366 	/* Now we could try to dump offended packet options */
367 
368 	msg->msg_flags |= MSG_ERRQUEUE;
369 	err = copied;
370 
371 	/* Reset and regenerate socket error */
372 	spin_lock_bh(&sk->sk_error_queue.lock);
373 	sk->sk_err = 0;
374 	if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
375 		sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
376 		spin_unlock_bh(&sk->sk_error_queue.lock);
377 		sk->sk_error_report(sk);
378 	} else {
379 		spin_unlock_bh(&sk->sk_error_queue.lock);
380 	}
381 
382 out_free_skb:
383 	kfree_skb(skb);
384 out:
385 	return err;
386 }
387 
388 
389 
390 int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
391 {
392 	struct ipv6_pinfo *np = inet6_sk(sk);
393 	struct inet6_skb_parm *opt = IP6CB(skb);
394 	unsigned char *nh = skb_network_header(skb);
395 
396 	if (np->rxopt.bits.rxinfo) {
397 		struct in6_pktinfo src_info;
398 
399 		src_info.ipi6_ifindex = opt->iif;
400 		ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
401 		put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
402 	}
403 
404 	if (np->rxopt.bits.rxhlim) {
405 		int hlim = ipv6_hdr(skb)->hop_limit;
406 		put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
407 	}
408 
409 	if (np->rxopt.bits.rxtclass) {
410 		int tclass = (ntohl(*(__be32 *)ipv6_hdr(skb)) >> 20) & 0xff;
411 		put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
412 	}
413 
414 	if (np->rxopt.bits.rxflow && (*(__be32 *)nh & IPV6_FLOWINFO_MASK)) {
415 		__be32 flowinfo = *(__be32 *)nh & IPV6_FLOWINFO_MASK;
416 		put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
417 	}
418 
419 	/* HbH is allowed only once */
420 	if (np->rxopt.bits.hopopts && opt->hop) {
421 		u8 *ptr = nh + opt->hop;
422 		put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
423 	}
424 
425 	if (opt->lastopt &&
426 	    (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
427 		/*
428 		 * Silly enough, but we need to reparse in order to
429 		 * report extension headers (except for HbH)
430 		 * in order.
431 		 *
432 		 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
433 		 * (and WILL NOT be) defined because
434 		 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
435 		 */
436 		unsigned int off = sizeof(struct ipv6hdr);
437 		u8 nexthdr = ipv6_hdr(skb)->nexthdr;
438 
439 		while (off <= opt->lastopt) {
440 			unsigned len;
441 			u8 *ptr = nh + off;
442 
443 			switch(nexthdr) {
444 			case IPPROTO_DSTOPTS:
445 				nexthdr = ptr[0];
446 				len = (ptr[1] + 1) << 3;
447 				if (np->rxopt.bits.dstopts)
448 					put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
449 				break;
450 			case IPPROTO_ROUTING:
451 				nexthdr = ptr[0];
452 				len = (ptr[1] + 1) << 3;
453 				if (np->rxopt.bits.srcrt)
454 					put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
455 				break;
456 			case IPPROTO_AH:
457 				nexthdr = ptr[0];
458 				len = (ptr[1] + 2) << 2;
459 				break;
460 			default:
461 				nexthdr = ptr[0];
462 				len = (ptr[1] + 1) << 3;
463 				break;
464 			}
465 
466 			off += len;
467 		}
468 	}
469 
470 	/* socket options in old style */
471 	if (np->rxopt.bits.rxoinfo) {
472 		struct in6_pktinfo src_info;
473 
474 		src_info.ipi6_ifindex = opt->iif;
475 		ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
476 		put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
477 	}
478 	if (np->rxopt.bits.rxohlim) {
479 		int hlim = ipv6_hdr(skb)->hop_limit;
480 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
481 	}
482 	if (np->rxopt.bits.ohopopts && opt->hop) {
483 		u8 *ptr = nh + opt->hop;
484 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
485 	}
486 	if (np->rxopt.bits.odstopts && opt->dst0) {
487 		u8 *ptr = nh + opt->dst0;
488 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
489 	}
490 	if (np->rxopt.bits.osrcrt && opt->srcrt) {
491 		struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
492 		put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
493 	}
494 	if (np->rxopt.bits.odstopts && opt->dst1) {
495 		u8 *ptr = nh + opt->dst1;
496 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
497 	}
498 	return 0;
499 }
500 
501 int datagram_send_ctl(struct net *net,
502 		      struct msghdr *msg, struct flowi *fl,
503 		      struct ipv6_txoptions *opt,
504 		      int *hlimit, int *tclass)
505 {
506 	struct in6_pktinfo *src_info;
507 	struct cmsghdr *cmsg;
508 	struct ipv6_rt_hdr *rthdr;
509 	struct ipv6_opt_hdr *hdr;
510 	int len;
511 	int err = 0;
512 
513 	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
514 		int addr_type;
515 
516 		if (!CMSG_OK(msg, cmsg)) {
517 			err = -EINVAL;
518 			goto exit_f;
519 		}
520 
521 		if (cmsg->cmsg_level != SOL_IPV6)
522 			continue;
523 
524 		switch (cmsg->cmsg_type) {
525 		case IPV6_PKTINFO:
526 		case IPV6_2292PKTINFO:
527 		    {
528 			struct net_device *dev = NULL;
529 
530 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
531 				err = -EINVAL;
532 				goto exit_f;
533 			}
534 
535 			src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
536 
537 			if (src_info->ipi6_ifindex) {
538 				if (fl->oif && src_info->ipi6_ifindex != fl->oif)
539 					return -EINVAL;
540 				fl->oif = src_info->ipi6_ifindex;
541 			}
542 
543 			addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
544 
545 			rcu_read_lock();
546 			if (fl->oif) {
547 				dev = dev_get_by_index_rcu(net, fl->oif);
548 				if (!dev) {
549 					rcu_read_unlock();
550 					return -ENODEV;
551 				}
552 			} else if (addr_type & IPV6_ADDR_LINKLOCAL) {
553 				rcu_read_unlock();
554 				return -EINVAL;
555 			}
556 
557 			if (addr_type != IPV6_ADDR_ANY) {
558 				int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
559 				if (!ipv6_chk_addr(net, &src_info->ipi6_addr,
560 						   strict ? dev : NULL, 0))
561 					err = -EINVAL;
562 				else
563 					ipv6_addr_copy(&fl->fl6_src, &src_info->ipi6_addr);
564 			}
565 
566 			rcu_read_unlock();
567 
568 			if (err)
569 				goto exit_f;
570 
571 			break;
572 		    }
573 
574 		case IPV6_FLOWINFO:
575 			if (cmsg->cmsg_len < CMSG_LEN(4)) {
576 				err = -EINVAL;
577 				goto exit_f;
578 			}
579 
580 			if (fl->fl6_flowlabel&IPV6_FLOWINFO_MASK) {
581 				if ((fl->fl6_flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
582 					err = -EINVAL;
583 					goto exit_f;
584 				}
585 			}
586 			fl->fl6_flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
587 			break;
588 
589 		case IPV6_2292HOPOPTS:
590 		case IPV6_HOPOPTS:
591 			if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
592 				err = -EINVAL;
593 				goto exit_f;
594 			}
595 
596 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
597 			len = ((hdr->hdrlen + 1) << 3);
598 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
599 				err = -EINVAL;
600 				goto exit_f;
601 			}
602 			if (!capable(CAP_NET_RAW)) {
603 				err = -EPERM;
604 				goto exit_f;
605 			}
606 			opt->opt_nflen += len;
607 			opt->hopopt = hdr;
608 			break;
609 
610 		case IPV6_2292DSTOPTS:
611 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
612 				err = -EINVAL;
613 				goto exit_f;
614 			}
615 
616 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
617 			len = ((hdr->hdrlen + 1) << 3);
618 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
619 				err = -EINVAL;
620 				goto exit_f;
621 			}
622 			if (!capable(CAP_NET_RAW)) {
623 				err = -EPERM;
624 				goto exit_f;
625 			}
626 			if (opt->dst1opt) {
627 				err = -EINVAL;
628 				goto exit_f;
629 			}
630 			opt->opt_flen += len;
631 			opt->dst1opt = hdr;
632 			break;
633 
634 		case IPV6_DSTOPTS:
635 		case IPV6_RTHDRDSTOPTS:
636 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
637 				err = -EINVAL;
638 				goto exit_f;
639 			}
640 
641 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
642 			len = ((hdr->hdrlen + 1) << 3);
643 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
644 				err = -EINVAL;
645 				goto exit_f;
646 			}
647 			if (!capable(CAP_NET_RAW)) {
648 				err = -EPERM;
649 				goto exit_f;
650 			}
651 			if (cmsg->cmsg_type == IPV6_DSTOPTS) {
652 				opt->opt_flen += len;
653 				opt->dst1opt = hdr;
654 			} else {
655 				opt->opt_nflen += len;
656 				opt->dst0opt = hdr;
657 			}
658 			break;
659 
660 		case IPV6_2292RTHDR:
661 		case IPV6_RTHDR:
662 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
663 				err = -EINVAL;
664 				goto exit_f;
665 			}
666 
667 			rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
668 
669 			switch (rthdr->type) {
670 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
671 			case IPV6_SRCRT_TYPE_2:
672 				if (rthdr->hdrlen != 2 ||
673 				    rthdr->segments_left != 1) {
674 					err = -EINVAL;
675 					goto exit_f;
676 				}
677 				break;
678 #endif
679 			default:
680 				err = -EINVAL;
681 				goto exit_f;
682 			}
683 
684 			len = ((rthdr->hdrlen + 1) << 3);
685 
686 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
687 				err = -EINVAL;
688 				goto exit_f;
689 			}
690 
691 			/* segments left must also match */
692 			if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
693 				err = -EINVAL;
694 				goto exit_f;
695 			}
696 
697 			opt->opt_nflen += len;
698 			opt->srcrt = rthdr;
699 
700 			if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
701 				int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
702 
703 				opt->opt_nflen += dsthdrlen;
704 				opt->dst0opt = opt->dst1opt;
705 				opt->dst1opt = NULL;
706 				opt->opt_flen -= dsthdrlen;
707 			}
708 
709 			break;
710 
711 		case IPV6_2292HOPLIMIT:
712 		case IPV6_HOPLIMIT:
713 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
714 				err = -EINVAL;
715 				goto exit_f;
716 			}
717 
718 			*hlimit = *(int *)CMSG_DATA(cmsg);
719 			if (*hlimit < -1 || *hlimit > 0xff) {
720 				err = -EINVAL;
721 				goto exit_f;
722 			}
723 
724 			break;
725 
726 		case IPV6_TCLASS:
727 		    {
728 			int tc;
729 
730 			err = -EINVAL;
731 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
732 				goto exit_f;
733 			}
734 
735 			tc = *(int *)CMSG_DATA(cmsg);
736 			if (tc < -1 || tc > 0xff)
737 				goto exit_f;
738 
739 			err = 0;
740 			*tclass = tc;
741 
742 			break;
743 		    }
744 		default:
745 			LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
746 				       cmsg->cmsg_type);
747 			err = -EINVAL;
748 			goto exit_f;
749 		}
750 	}
751 
752 exit_f:
753 	return err;
754 }
755