xref: /linux/net/ipv6/datagram.c (revision eb2bce7f5e7ac1ca6da434461217fadf3c688d2c)
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 = icmp6_hdr(skb);
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) -
231 				  skb_network_header(skb);
232 	serr->port = port;
233 
234 	__skb_pull(skb, payload - skb->data);
235 	skb_reset_transport_header(skb);
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 	skb_put(skb, sizeof(struct ipv6hdr));
256 	skb_reset_network_header(skb);
257 	iph = ipv6_hdr(skb);
258 	ipv6_addr_copy(&iph->daddr, &fl->fl6_dst);
259 
260 	serr = SKB_EXT_ERR(skb);
261 	serr->ee.ee_errno = err;
262 	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
263 	serr->ee.ee_type = 0;
264 	serr->ee.ee_code = 0;
265 	serr->ee.ee_pad = 0;
266 	serr->ee.ee_info = info;
267 	serr->ee.ee_data = 0;
268 	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
269 	serr->port = fl->fl_ip_dport;
270 
271 	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
272 	skb_reset_transport_header(skb);
273 
274 	if (sock_queue_err_skb(sk, skb))
275 		kfree_skb(skb);
276 }
277 
278 /*
279  *	Handle MSG_ERRQUEUE
280  */
281 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len)
282 {
283 	struct ipv6_pinfo *np = inet6_sk(sk);
284 	struct sock_exterr_skb *serr;
285 	struct sk_buff *skb, *skb2;
286 	struct sockaddr_in6 *sin;
287 	struct {
288 		struct sock_extended_err ee;
289 		struct sockaddr_in6	 offender;
290 	} errhdr;
291 	int err;
292 	int copied;
293 
294 	err = -EAGAIN;
295 	skb = skb_dequeue(&sk->sk_error_queue);
296 	if (skb == NULL)
297 		goto out;
298 
299 	copied = skb->len;
300 	if (copied > len) {
301 		msg->msg_flags |= MSG_TRUNC;
302 		copied = len;
303 	}
304 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
305 	if (err)
306 		goto out_free_skb;
307 
308 	sock_recv_timestamp(msg, sk, skb);
309 
310 	serr = SKB_EXT_ERR(skb);
311 
312 	sin = (struct sockaddr_in6 *)msg->msg_name;
313 	if (sin) {
314 		const unsigned char *nh = skb_network_header(skb);
315 		sin->sin6_family = AF_INET6;
316 		sin->sin6_flowinfo = 0;
317 		sin->sin6_port = serr->port;
318 		sin->sin6_scope_id = 0;
319 		if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
320 			ipv6_addr_copy(&sin->sin6_addr,
321 				  (struct in6_addr *)(nh + serr->addr_offset));
322 			if (np->sndflow)
323 				sin->sin6_flowinfo =
324 					(*(__be32 *)(nh + serr->addr_offset - 24) &
325 					 IPV6_FLOWINFO_MASK);
326 			if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
327 				sin->sin6_scope_id = IP6CB(skb)->iif;
328 		} else {
329 			ipv6_addr_set(&sin->sin6_addr, 0, 0,
330 				      htonl(0xffff),
331 				      *(__be32 *)(nh + serr->addr_offset));
332 		}
333 	}
334 
335 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
336 	sin = &errhdr.offender;
337 	sin->sin6_family = AF_UNSPEC;
338 	if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
339 		sin->sin6_family = AF_INET6;
340 		sin->sin6_flowinfo = 0;
341 		sin->sin6_scope_id = 0;
342 		if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6) {
343 			ipv6_addr_copy(&sin->sin6_addr, &ipv6_hdr(skb)->saddr);
344 			if (np->rxopt.all)
345 				datagram_recv_ctl(sk, msg, skb);
346 			if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
347 				sin->sin6_scope_id = IP6CB(skb)->iif;
348 		} else {
349 			struct inet_sock *inet = inet_sk(sk);
350 
351 			ipv6_addr_set(&sin->sin6_addr, 0, 0,
352 				      htonl(0xffff), ip_hdr(skb)->saddr);
353 			if (inet->cmsg_flags)
354 				ip_cmsg_recv(msg, skb);
355 		}
356 	}
357 
358 	put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
359 
360 	/* Now we could try to dump offended packet options */
361 
362 	msg->msg_flags |= MSG_ERRQUEUE;
363 	err = copied;
364 
365 	/* Reset and regenerate socket error */
366 	spin_lock_bh(&sk->sk_error_queue.lock);
367 	sk->sk_err = 0;
368 	if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
369 		sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
370 		spin_unlock_bh(&sk->sk_error_queue.lock);
371 		sk->sk_error_report(sk);
372 	} else {
373 		spin_unlock_bh(&sk->sk_error_queue.lock);
374 	}
375 
376 out_free_skb:
377 	kfree_skb(skb);
378 out:
379 	return err;
380 }
381 
382 
383 
384 int datagram_recv_ctl(struct sock *sk, struct msghdr *msg, struct sk_buff *skb)
385 {
386 	struct ipv6_pinfo *np = inet6_sk(sk);
387 	struct inet6_skb_parm *opt = IP6CB(skb);
388 	unsigned char *nh = skb_network_header(skb);
389 
390 	if (np->rxopt.bits.rxinfo) {
391 		struct in6_pktinfo src_info;
392 
393 		src_info.ipi6_ifindex = opt->iif;
394 		ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
395 		put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
396 	}
397 
398 	if (np->rxopt.bits.rxhlim) {
399 		int hlim = ipv6_hdr(skb)->hop_limit;
400 		put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
401 	}
402 
403 	if (np->rxopt.bits.rxtclass) {
404 		int tclass = (ntohl(*(__be32 *)ipv6_hdr(skb)) >> 20) & 0xff;
405 		put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
406 	}
407 
408 	if (np->rxopt.bits.rxflow && (*(__be32 *)nh & IPV6_FLOWINFO_MASK)) {
409 		__be32 flowinfo = *(__be32 *)nh & IPV6_FLOWINFO_MASK;
410 		put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
411 	}
412 
413 	/* HbH is allowed only once */
414 	if (np->rxopt.bits.hopopts && opt->hop) {
415 		u8 *ptr = nh + opt->hop;
416 		put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
417 	}
418 
419 	if (opt->lastopt &&
420 	    (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
421 		/*
422 		 * Silly enough, but we need to reparse in order to
423 		 * report extension headers (except for HbH)
424 		 * in order.
425 		 *
426 		 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
427 		 * (and WILL NOT be) defined because
428 		 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
429 		 */
430 		unsigned int off = sizeof(struct ipv6hdr);
431 		u8 nexthdr = ipv6_hdr(skb)->nexthdr;
432 
433 		while (off <= opt->lastopt) {
434 			unsigned len;
435 			u8 *ptr = nh + off;
436 
437 			switch(nexthdr) {
438 			case IPPROTO_DSTOPTS:
439 				nexthdr = ptr[0];
440 				len = (ptr[1] + 1) << 3;
441 				if (np->rxopt.bits.dstopts)
442 					put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
443 				break;
444 			case IPPROTO_ROUTING:
445 				nexthdr = ptr[0];
446 				len = (ptr[1] + 1) << 3;
447 				if (np->rxopt.bits.srcrt)
448 					put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
449 				break;
450 			case IPPROTO_AH:
451 				nexthdr = ptr[0];
452 				len = (ptr[1] + 2) << 2;
453 				break;
454 			default:
455 				nexthdr = ptr[0];
456 				len = (ptr[1] + 1) << 3;
457 				break;
458 			}
459 
460 			off += len;
461 		}
462 	}
463 
464 	/* socket options in old style */
465 	if (np->rxopt.bits.rxoinfo) {
466 		struct in6_pktinfo src_info;
467 
468 		src_info.ipi6_ifindex = opt->iif;
469 		ipv6_addr_copy(&src_info.ipi6_addr, &ipv6_hdr(skb)->daddr);
470 		put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
471 	}
472 	if (np->rxopt.bits.rxohlim) {
473 		int hlim = ipv6_hdr(skb)->hop_limit;
474 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
475 	}
476 	if (np->rxopt.bits.ohopopts && opt->hop) {
477 		u8 *ptr = nh + opt->hop;
478 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
479 	}
480 	if (np->rxopt.bits.odstopts && opt->dst0) {
481 		u8 *ptr = nh + opt->dst0;
482 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
483 	}
484 	if (np->rxopt.bits.osrcrt && opt->srcrt) {
485 		struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
486 		put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
487 	}
488 	if (np->rxopt.bits.odstopts && opt->dst1) {
489 		u8 *ptr = nh + opt->dst1;
490 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
491 	}
492 	return 0;
493 }
494 
495 int datagram_send_ctl(struct msghdr *msg, struct flowi *fl,
496 		      struct ipv6_txoptions *opt,
497 		      int *hlimit, int *tclass)
498 {
499 	struct in6_pktinfo *src_info;
500 	struct cmsghdr *cmsg;
501 	struct ipv6_rt_hdr *rthdr;
502 	struct ipv6_opt_hdr *hdr;
503 	int len;
504 	int err = 0;
505 
506 	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
507 		int addr_type;
508 		struct net_device *dev = NULL;
509 
510 		if (!CMSG_OK(msg, cmsg)) {
511 			err = -EINVAL;
512 			goto exit_f;
513 		}
514 
515 		if (cmsg->cmsg_level != SOL_IPV6)
516 			continue;
517 
518 		switch (cmsg->cmsg_type) {
519 		case IPV6_PKTINFO:
520 		case IPV6_2292PKTINFO:
521 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
522 				err = -EINVAL;
523 				goto exit_f;
524 			}
525 
526 			src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
527 
528 			if (src_info->ipi6_ifindex) {
529 				if (fl->oif && src_info->ipi6_ifindex != fl->oif)
530 					return -EINVAL;
531 				fl->oif = src_info->ipi6_ifindex;
532 			}
533 
534 			addr_type = ipv6_addr_type(&src_info->ipi6_addr);
535 
536 			if (addr_type == IPV6_ADDR_ANY)
537 				break;
538 
539 			if (addr_type & IPV6_ADDR_LINKLOCAL) {
540 				if (!src_info->ipi6_ifindex)
541 					return -EINVAL;
542 				else {
543 					dev = dev_get_by_index(src_info->ipi6_ifindex);
544 					if (!dev)
545 						return -ENODEV;
546 				}
547 			}
548 			if (!ipv6_chk_addr(&src_info->ipi6_addr, dev, 0)) {
549 				if (dev)
550 					dev_put(dev);
551 				err = -EINVAL;
552 				goto exit_f;
553 			}
554 			if (dev)
555 				dev_put(dev);
556 
557 			ipv6_addr_copy(&fl->fl6_src, &src_info->ipi6_addr);
558 			break;
559 
560 		case IPV6_FLOWINFO:
561 			if (cmsg->cmsg_len < CMSG_LEN(4)) {
562 				err = -EINVAL;
563 				goto exit_f;
564 			}
565 
566 			if (fl->fl6_flowlabel&IPV6_FLOWINFO_MASK) {
567 				if ((fl->fl6_flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
568 					err = -EINVAL;
569 					goto exit_f;
570 				}
571 			}
572 			fl->fl6_flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
573 			break;
574 
575 		case IPV6_2292HOPOPTS:
576 		case IPV6_HOPOPTS:
577 			if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
578 				err = -EINVAL;
579 				goto exit_f;
580 			}
581 
582 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
583 			len = ((hdr->hdrlen + 1) << 3);
584 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
585 				err = -EINVAL;
586 				goto exit_f;
587 			}
588 			if (!capable(CAP_NET_RAW)) {
589 				err = -EPERM;
590 				goto exit_f;
591 			}
592 			opt->opt_nflen += len;
593 			opt->hopopt = hdr;
594 			break;
595 
596 		case IPV6_2292DSTOPTS:
597 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
598 				err = -EINVAL;
599 				goto exit_f;
600 			}
601 
602 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
603 			len = ((hdr->hdrlen + 1) << 3);
604 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
605 				err = -EINVAL;
606 				goto exit_f;
607 			}
608 			if (!capable(CAP_NET_RAW)) {
609 				err = -EPERM;
610 				goto exit_f;
611 			}
612 			if (opt->dst1opt) {
613 				err = -EINVAL;
614 				goto exit_f;
615 			}
616 			opt->opt_flen += len;
617 			opt->dst1opt = hdr;
618 			break;
619 
620 		case IPV6_DSTOPTS:
621 		case IPV6_RTHDRDSTOPTS:
622 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
623 				err = -EINVAL;
624 				goto exit_f;
625 			}
626 
627 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
628 			len = ((hdr->hdrlen + 1) << 3);
629 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
630 				err = -EINVAL;
631 				goto exit_f;
632 			}
633 			if (!capable(CAP_NET_RAW)) {
634 				err = -EPERM;
635 				goto exit_f;
636 			}
637 			if (cmsg->cmsg_type == IPV6_DSTOPTS) {
638 				opt->opt_flen += len;
639 				opt->dst1opt = hdr;
640 			} else {
641 				opt->opt_nflen += len;
642 				opt->dst0opt = hdr;
643 			}
644 			break;
645 
646 		case IPV6_2292RTHDR:
647 		case IPV6_RTHDR:
648 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
649 				err = -EINVAL;
650 				goto exit_f;
651 			}
652 
653 			rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
654 
655 			switch (rthdr->type) {
656 			case IPV6_SRCRT_TYPE_0:
657 #ifdef CONFIG_IPV6_MIP6
658 			case IPV6_SRCRT_TYPE_2:
659 #endif
660 				break;
661 			default:
662 				err = -EINVAL;
663 				goto exit_f;
664 			}
665 
666 			len = ((rthdr->hdrlen + 1) << 3);
667 
668 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
669 				err = -EINVAL;
670 				goto exit_f;
671 			}
672 
673 			/* segments left must also match */
674 			if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
675 				err = -EINVAL;
676 				goto exit_f;
677 			}
678 
679 			opt->opt_nflen += len;
680 			opt->srcrt = rthdr;
681 
682 			if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
683 				int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
684 
685 				opt->opt_nflen += dsthdrlen;
686 				opt->dst0opt = opt->dst1opt;
687 				opt->dst1opt = NULL;
688 				opt->opt_flen -= dsthdrlen;
689 			}
690 
691 			break;
692 
693 		case IPV6_2292HOPLIMIT:
694 		case IPV6_HOPLIMIT:
695 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
696 				err = -EINVAL;
697 				goto exit_f;
698 			}
699 
700 			*hlimit = *(int *)CMSG_DATA(cmsg);
701 			break;
702 
703 		case IPV6_TCLASS:
704 		    {
705 			int tc;
706 
707 			err = -EINVAL;
708 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
709 				goto exit_f;
710 			}
711 
712 			tc = *(int *)CMSG_DATA(cmsg);
713 			if (tc < -1 || tc > 0xff)
714 				goto exit_f;
715 
716 			err = 0;
717 			*tclass = tc;
718 
719 			break;
720 		    }
721 		default:
722 			LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
723 				       cmsg->cmsg_type);
724 			err = -EINVAL;
725 			break;
726 		}
727 	}
728 
729 exit_f:
730 	return err;
731 }
732