xref: /openbmc/linux/net/ipv6/datagram.c (revision 33ac9dba)
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 #include <linux/export.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 #include <net/dsfield.h>
34 
35 #include <linux/errqueue.h>
36 #include <asm/uaccess.h>
37 
38 static bool ipv6_mapped_addr_any(const struct in6_addr *a)
39 {
40 	return ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0);
41 }
42 
43 int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
44 {
45 	struct sockaddr_in6	*usin = (struct sockaddr_in6 *) uaddr;
46 	struct inet_sock      	*inet = inet_sk(sk);
47 	struct ipv6_pinfo      	*np = inet6_sk(sk);
48 	struct in6_addr		*daddr, *final_p, final;
49 	struct dst_entry	*dst;
50 	struct flowi6		fl6;
51 	struct ip6_flowlabel	*flowlabel = NULL;
52 	struct ipv6_txoptions   *opt;
53 	int			addr_type;
54 	int			err;
55 
56 	if (usin->sin6_family == AF_INET) {
57 		if (__ipv6_only_sock(sk))
58 			return -EAFNOSUPPORT;
59 		err = ip4_datagram_connect(sk, uaddr, addr_len);
60 		goto ipv4_connected;
61 	}
62 
63 	if (addr_len < SIN6_LEN_RFC2133)
64 		return -EINVAL;
65 
66 	if (usin->sin6_family != AF_INET6)
67 		return -EAFNOSUPPORT;
68 
69 	memset(&fl6, 0, sizeof(fl6));
70 	if (np->sndflow) {
71 		fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
72 		if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
73 			flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
74 			if (flowlabel == NULL)
75 				return -EINVAL;
76 		}
77 	}
78 
79 	addr_type = ipv6_addr_type(&usin->sin6_addr);
80 
81 	if (addr_type == IPV6_ADDR_ANY) {
82 		/*
83 		 *	connect to self
84 		 */
85 		usin->sin6_addr.s6_addr[15] = 0x01;
86 	}
87 
88 	daddr = &usin->sin6_addr;
89 
90 	if (addr_type == IPV6_ADDR_MAPPED) {
91 		struct sockaddr_in sin;
92 
93 		if (__ipv6_only_sock(sk)) {
94 			err = -ENETUNREACH;
95 			goto out;
96 		}
97 		sin.sin_family = AF_INET;
98 		sin.sin_addr.s_addr = daddr->s6_addr32[3];
99 		sin.sin_port = usin->sin6_port;
100 
101 		err = ip4_datagram_connect(sk,
102 					   (struct sockaddr *) &sin,
103 					   sizeof(sin));
104 
105 ipv4_connected:
106 		if (err)
107 			goto out;
108 
109 		ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
110 
111 		if (ipv6_addr_any(&np->saddr) ||
112 		    ipv6_mapped_addr_any(&np->saddr))
113 			ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
114 
115 		if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
116 		    ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
117 			ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
118 					       &sk->sk_v6_rcv_saddr);
119 			if (sk->sk_prot->rehash)
120 				sk->sk_prot->rehash(sk);
121 		}
122 
123 		goto out;
124 	}
125 
126 	if (__ipv6_addr_needs_scope_id(addr_type)) {
127 		if (addr_len >= sizeof(struct sockaddr_in6) &&
128 		    usin->sin6_scope_id) {
129 			if (sk->sk_bound_dev_if &&
130 			    sk->sk_bound_dev_if != usin->sin6_scope_id) {
131 				err = -EINVAL;
132 				goto out;
133 			}
134 			sk->sk_bound_dev_if = usin->sin6_scope_id;
135 		}
136 
137 		if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
138 			sk->sk_bound_dev_if = np->mcast_oif;
139 
140 		/* Connect to link-local address requires an interface */
141 		if (!sk->sk_bound_dev_if) {
142 			err = -EINVAL;
143 			goto out;
144 		}
145 	}
146 
147 	sk->sk_v6_daddr = *daddr;
148 	np->flow_label = fl6.flowlabel;
149 
150 	inet->inet_dport = usin->sin6_port;
151 
152 	/*
153 	 *	Check for a route to destination an obtain the
154 	 *	destination cache for it.
155 	 */
156 
157 	fl6.flowi6_proto = sk->sk_protocol;
158 	fl6.daddr = sk->sk_v6_daddr;
159 	fl6.saddr = np->saddr;
160 	fl6.flowi6_oif = sk->sk_bound_dev_if;
161 	fl6.flowi6_mark = sk->sk_mark;
162 	fl6.fl6_dport = inet->inet_dport;
163 	fl6.fl6_sport = inet->inet_sport;
164 
165 	if (!fl6.flowi6_oif && (addr_type&IPV6_ADDR_MULTICAST))
166 		fl6.flowi6_oif = np->mcast_oif;
167 
168 	security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
169 
170 	opt = flowlabel ? flowlabel->opt : np->opt;
171 	final_p = fl6_update_dst(&fl6, opt, &final);
172 
173 	dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
174 	err = 0;
175 	if (IS_ERR(dst)) {
176 		err = PTR_ERR(dst);
177 		goto out;
178 	}
179 
180 	/* source address lookup done in ip6_dst_lookup */
181 
182 	if (ipv6_addr_any(&np->saddr))
183 		np->saddr = fl6.saddr;
184 
185 	if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
186 		sk->sk_v6_rcv_saddr = fl6.saddr;
187 		inet->inet_rcv_saddr = LOOPBACK4_IPV6;
188 		if (sk->sk_prot->rehash)
189 			sk->sk_prot->rehash(sk);
190 	}
191 
192 	ip6_dst_store(sk, dst,
193 		      ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ?
194 		      &sk->sk_v6_daddr : NULL,
195 #ifdef CONFIG_IPV6_SUBTREES
196 		      ipv6_addr_equal(&fl6.saddr, &np->saddr) ?
197 		      &np->saddr :
198 #endif
199 		      NULL);
200 
201 	sk->sk_state = TCP_ESTABLISHED;
202 	ip6_set_txhash(sk);
203 out:
204 	fl6_sock_release(flowlabel);
205 	return err;
206 }
207 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
208 
209 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
210 				 int addr_len)
211 {
212 	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
213 	if (sin6->sin6_family != AF_INET6)
214 		return -EAFNOSUPPORT;
215 	return ip6_datagram_connect(sk, uaddr, addr_len);
216 }
217 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
218 
219 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
220 		     __be16 port, u32 info, u8 *payload)
221 {
222 	struct ipv6_pinfo *np  = inet6_sk(sk);
223 	struct icmp6hdr *icmph = icmp6_hdr(skb);
224 	struct sock_exterr_skb *serr;
225 
226 	if (!np->recverr)
227 		return;
228 
229 	skb = skb_clone(skb, GFP_ATOMIC);
230 	if (!skb)
231 		return;
232 
233 	skb->protocol = htons(ETH_P_IPV6);
234 
235 	serr = SKB_EXT_ERR(skb);
236 	serr->ee.ee_errno = err;
237 	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
238 	serr->ee.ee_type = icmph->icmp6_type;
239 	serr->ee.ee_code = icmph->icmp6_code;
240 	serr->ee.ee_pad = 0;
241 	serr->ee.ee_info = info;
242 	serr->ee.ee_data = 0;
243 	serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
244 				  skb_network_header(skb);
245 	serr->port = port;
246 
247 	__skb_pull(skb, payload - skb->data);
248 	skb_reset_transport_header(skb);
249 
250 	if (sock_queue_err_skb(sk, skb))
251 		kfree_skb(skb);
252 }
253 
254 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
255 {
256 	struct ipv6_pinfo *np = inet6_sk(sk);
257 	struct sock_exterr_skb *serr;
258 	struct ipv6hdr *iph;
259 	struct sk_buff *skb;
260 
261 	if (!np->recverr)
262 		return;
263 
264 	skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
265 	if (!skb)
266 		return;
267 
268 	skb->protocol = htons(ETH_P_IPV6);
269 
270 	skb_put(skb, sizeof(struct ipv6hdr));
271 	skb_reset_network_header(skb);
272 	iph = ipv6_hdr(skb);
273 	iph->daddr = fl6->daddr;
274 
275 	serr = SKB_EXT_ERR(skb);
276 	serr->ee.ee_errno = err;
277 	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
278 	serr->ee.ee_type = 0;
279 	serr->ee.ee_code = 0;
280 	serr->ee.ee_pad = 0;
281 	serr->ee.ee_info = info;
282 	serr->ee.ee_data = 0;
283 	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
284 	serr->port = fl6->fl6_dport;
285 
286 	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
287 	skb_reset_transport_header(skb);
288 
289 	if (sock_queue_err_skb(sk, skb))
290 		kfree_skb(skb);
291 }
292 
293 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
294 {
295 	struct ipv6_pinfo *np = inet6_sk(sk);
296 	struct ipv6hdr *iph;
297 	struct sk_buff *skb;
298 	struct ip6_mtuinfo *mtu_info;
299 
300 	if (!np->rxopt.bits.rxpmtu)
301 		return;
302 
303 	skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
304 	if (!skb)
305 		return;
306 
307 	skb_put(skb, sizeof(struct ipv6hdr));
308 	skb_reset_network_header(skb);
309 	iph = ipv6_hdr(skb);
310 	iph->daddr = fl6->daddr;
311 
312 	mtu_info = IP6CBMTU(skb);
313 
314 	mtu_info->ip6m_mtu = mtu;
315 	mtu_info->ip6m_addr.sin6_family = AF_INET6;
316 	mtu_info->ip6m_addr.sin6_port = 0;
317 	mtu_info->ip6m_addr.sin6_flowinfo = 0;
318 	mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
319 	mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
320 
321 	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
322 	skb_reset_transport_header(skb);
323 
324 	skb = xchg(&np->rxpmtu, skb);
325 	kfree_skb(skb);
326 }
327 
328 /*
329  *	Handle MSG_ERRQUEUE
330  */
331 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
332 {
333 	struct ipv6_pinfo *np = inet6_sk(sk);
334 	struct sock_exterr_skb *serr;
335 	struct sk_buff *skb, *skb2;
336 	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
337 	struct {
338 		struct sock_extended_err ee;
339 		struct sockaddr_in6	 offender;
340 	} errhdr;
341 	int err;
342 	int copied;
343 
344 	err = -EAGAIN;
345 	skb = skb_dequeue(&sk->sk_error_queue);
346 	if (skb == NULL)
347 		goto out;
348 
349 	copied = skb->len;
350 	if (copied > len) {
351 		msg->msg_flags |= MSG_TRUNC;
352 		copied = len;
353 	}
354 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
355 	if (err)
356 		goto out_free_skb;
357 
358 	sock_recv_timestamp(msg, sk, skb);
359 
360 	serr = SKB_EXT_ERR(skb);
361 
362 	if (sin) {
363 		const unsigned char *nh = skb_network_header(skb);
364 		sin->sin6_family = AF_INET6;
365 		sin->sin6_flowinfo = 0;
366 		sin->sin6_port = serr->port;
367 		if (skb->protocol == htons(ETH_P_IPV6)) {
368 			const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
369 								  struct ipv6hdr, daddr);
370 			sin->sin6_addr = ip6h->daddr;
371 			if (np->sndflow)
372 				sin->sin6_flowinfo = ip6_flowinfo(ip6h);
373 			sin->sin6_scope_id =
374 				ipv6_iface_scope_id(&sin->sin6_addr,
375 						    IP6CB(skb)->iif);
376 		} else {
377 			ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
378 					       &sin->sin6_addr);
379 			sin->sin6_scope_id = 0;
380 		}
381 		*addr_len = sizeof(*sin);
382 	}
383 
384 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
385 	sin = &errhdr.offender;
386 	sin->sin6_family = AF_UNSPEC;
387 	if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
388 		sin->sin6_family = AF_INET6;
389 		sin->sin6_flowinfo = 0;
390 		sin->sin6_port = 0;
391 		if (np->rxopt.all)
392 			ip6_datagram_recv_common_ctl(sk, msg, skb);
393 		if (skb->protocol == htons(ETH_P_IPV6)) {
394 			sin->sin6_addr = ipv6_hdr(skb)->saddr;
395 			if (np->rxopt.all)
396 				ip6_datagram_recv_specific_ctl(sk, msg, skb);
397 			sin->sin6_scope_id =
398 				ipv6_iface_scope_id(&sin->sin6_addr,
399 						    IP6CB(skb)->iif);
400 		} else {
401 			struct inet_sock *inet = inet_sk(sk);
402 
403 			ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
404 					       &sin->sin6_addr);
405 			sin->sin6_scope_id = 0;
406 			if (inet->cmsg_flags)
407 				ip_cmsg_recv(msg, skb);
408 		}
409 	}
410 
411 	put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
412 
413 	/* Now we could try to dump offended packet options */
414 
415 	msg->msg_flags |= MSG_ERRQUEUE;
416 	err = copied;
417 
418 	/* Reset and regenerate socket error */
419 	spin_lock_bh(&sk->sk_error_queue.lock);
420 	sk->sk_err = 0;
421 	if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
422 		sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
423 		spin_unlock_bh(&sk->sk_error_queue.lock);
424 		sk->sk_error_report(sk);
425 	} else {
426 		spin_unlock_bh(&sk->sk_error_queue.lock);
427 	}
428 
429 out_free_skb:
430 	kfree_skb(skb);
431 out:
432 	return err;
433 }
434 EXPORT_SYMBOL_GPL(ipv6_recv_error);
435 
436 /*
437  *	Handle IPV6_RECVPATHMTU
438  */
439 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
440 		     int *addr_len)
441 {
442 	struct ipv6_pinfo *np = inet6_sk(sk);
443 	struct sk_buff *skb;
444 	struct ip6_mtuinfo mtu_info;
445 	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
446 	int err;
447 	int copied;
448 
449 	err = -EAGAIN;
450 	skb = xchg(&np->rxpmtu, NULL);
451 	if (skb == NULL)
452 		goto out;
453 
454 	copied = skb->len;
455 	if (copied > len) {
456 		msg->msg_flags |= MSG_TRUNC;
457 		copied = len;
458 	}
459 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
460 	if (err)
461 		goto out_free_skb;
462 
463 	sock_recv_timestamp(msg, sk, skb);
464 
465 	memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
466 
467 	if (sin) {
468 		sin->sin6_family = AF_INET6;
469 		sin->sin6_flowinfo = 0;
470 		sin->sin6_port = 0;
471 		sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
472 		sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
473 		*addr_len = sizeof(*sin);
474 	}
475 
476 	put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
477 
478 	err = copied;
479 
480 out_free_skb:
481 	kfree_skb(skb);
482 out:
483 	return err;
484 }
485 
486 
487 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
488 				 struct sk_buff *skb)
489 {
490 	struct ipv6_pinfo *np = inet6_sk(sk);
491 	bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
492 
493 	if (np->rxopt.bits.rxinfo) {
494 		struct in6_pktinfo src_info;
495 
496 		if (is_ipv6) {
497 			src_info.ipi6_ifindex = IP6CB(skb)->iif;
498 			src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
499 		} else {
500 			src_info.ipi6_ifindex =
501 				PKTINFO_SKB_CB(skb)->ipi_ifindex;
502 			ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
503 					       &src_info.ipi6_addr);
504 		}
505 		put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
506 	}
507 }
508 
509 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
510 				    struct sk_buff *skb)
511 {
512 	struct ipv6_pinfo *np = inet6_sk(sk);
513 	struct inet6_skb_parm *opt = IP6CB(skb);
514 	unsigned char *nh = skb_network_header(skb);
515 
516 	if (np->rxopt.bits.rxhlim) {
517 		int hlim = ipv6_hdr(skb)->hop_limit;
518 		put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
519 	}
520 
521 	if (np->rxopt.bits.rxtclass) {
522 		int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
523 		put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
524 	}
525 
526 	if (np->rxopt.bits.rxflow) {
527 		__be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
528 		if (flowinfo)
529 			put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
530 	}
531 
532 	/* HbH is allowed only once */
533 	if (np->rxopt.bits.hopopts && opt->hop) {
534 		u8 *ptr = nh + opt->hop;
535 		put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
536 	}
537 
538 	if (opt->lastopt &&
539 	    (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
540 		/*
541 		 * Silly enough, but we need to reparse in order to
542 		 * report extension headers (except for HbH)
543 		 * in order.
544 		 *
545 		 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
546 		 * (and WILL NOT be) defined because
547 		 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
548 		 */
549 		unsigned int off = sizeof(struct ipv6hdr);
550 		u8 nexthdr = ipv6_hdr(skb)->nexthdr;
551 
552 		while (off <= opt->lastopt) {
553 			unsigned int len;
554 			u8 *ptr = nh + off;
555 
556 			switch (nexthdr) {
557 			case IPPROTO_DSTOPTS:
558 				nexthdr = ptr[0];
559 				len = (ptr[1] + 1) << 3;
560 				if (np->rxopt.bits.dstopts)
561 					put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
562 				break;
563 			case IPPROTO_ROUTING:
564 				nexthdr = ptr[0];
565 				len = (ptr[1] + 1) << 3;
566 				if (np->rxopt.bits.srcrt)
567 					put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
568 				break;
569 			case IPPROTO_AH:
570 				nexthdr = ptr[0];
571 				len = (ptr[1] + 2) << 2;
572 				break;
573 			default:
574 				nexthdr = ptr[0];
575 				len = (ptr[1] + 1) << 3;
576 				break;
577 			}
578 
579 			off += len;
580 		}
581 	}
582 
583 	/* socket options in old style */
584 	if (np->rxopt.bits.rxoinfo) {
585 		struct in6_pktinfo src_info;
586 
587 		src_info.ipi6_ifindex = opt->iif;
588 		src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
589 		put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
590 	}
591 	if (np->rxopt.bits.rxohlim) {
592 		int hlim = ipv6_hdr(skb)->hop_limit;
593 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
594 	}
595 	if (np->rxopt.bits.ohopopts && opt->hop) {
596 		u8 *ptr = nh + opt->hop;
597 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
598 	}
599 	if (np->rxopt.bits.odstopts && opt->dst0) {
600 		u8 *ptr = nh + opt->dst0;
601 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
602 	}
603 	if (np->rxopt.bits.osrcrt && opt->srcrt) {
604 		struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
605 		put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
606 	}
607 	if (np->rxopt.bits.odstopts && opt->dst1) {
608 		u8 *ptr = nh + opt->dst1;
609 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
610 	}
611 	if (np->rxopt.bits.rxorigdstaddr) {
612 		struct sockaddr_in6 sin6;
613 		__be16 *ports = (__be16 *) skb_transport_header(skb);
614 
615 		if (skb_transport_offset(skb) + 4 <= skb->len) {
616 			/* All current transport protocols have the port numbers in the
617 			 * first four bytes of the transport header and this function is
618 			 * written with this assumption in mind.
619 			 */
620 
621 			sin6.sin6_family = AF_INET6;
622 			sin6.sin6_addr = ipv6_hdr(skb)->daddr;
623 			sin6.sin6_port = ports[1];
624 			sin6.sin6_flowinfo = 0;
625 			sin6.sin6_scope_id =
626 				ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
627 						    opt->iif);
628 
629 			put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
630 		}
631 	}
632 }
633 
634 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
635 			  struct sk_buff *skb)
636 {
637 	ip6_datagram_recv_common_ctl(sk, msg, skb);
638 	ip6_datagram_recv_specific_ctl(sk, msg, skb);
639 }
640 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
641 
642 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
643 			  struct msghdr *msg, struct flowi6 *fl6,
644 			  struct ipv6_txoptions *opt,
645 			  int *hlimit, int *tclass, int *dontfrag)
646 {
647 	struct in6_pktinfo *src_info;
648 	struct cmsghdr *cmsg;
649 	struct ipv6_rt_hdr *rthdr;
650 	struct ipv6_opt_hdr *hdr;
651 	int len;
652 	int err = 0;
653 
654 	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
655 		int addr_type;
656 
657 		if (!CMSG_OK(msg, cmsg)) {
658 			err = -EINVAL;
659 			goto exit_f;
660 		}
661 
662 		if (cmsg->cmsg_level != SOL_IPV6)
663 			continue;
664 
665 		switch (cmsg->cmsg_type) {
666 		case IPV6_PKTINFO:
667 		case IPV6_2292PKTINFO:
668 		    {
669 			struct net_device *dev = NULL;
670 
671 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
672 				err = -EINVAL;
673 				goto exit_f;
674 			}
675 
676 			src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
677 
678 			if (src_info->ipi6_ifindex) {
679 				if (fl6->flowi6_oif &&
680 				    src_info->ipi6_ifindex != fl6->flowi6_oif)
681 					return -EINVAL;
682 				fl6->flowi6_oif = src_info->ipi6_ifindex;
683 			}
684 
685 			addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
686 
687 			rcu_read_lock();
688 			if (fl6->flowi6_oif) {
689 				dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
690 				if (!dev) {
691 					rcu_read_unlock();
692 					return -ENODEV;
693 				}
694 			} else if (addr_type & IPV6_ADDR_LINKLOCAL) {
695 				rcu_read_unlock();
696 				return -EINVAL;
697 			}
698 
699 			if (addr_type != IPV6_ADDR_ANY) {
700 				int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
701 				if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
702 				    !ipv6_chk_addr(net, &src_info->ipi6_addr,
703 						   strict ? dev : NULL, 0) &&
704 				    !ipv6_chk_acast_addr_src(net, dev,
705 							     &src_info->ipi6_addr))
706 					err = -EINVAL;
707 				else
708 					fl6->saddr = src_info->ipi6_addr;
709 			}
710 
711 			rcu_read_unlock();
712 
713 			if (err)
714 				goto exit_f;
715 
716 			break;
717 		    }
718 
719 		case IPV6_FLOWINFO:
720 			if (cmsg->cmsg_len < CMSG_LEN(4)) {
721 				err = -EINVAL;
722 				goto exit_f;
723 			}
724 
725 			if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
726 				if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
727 					err = -EINVAL;
728 					goto exit_f;
729 				}
730 			}
731 			fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
732 			break;
733 
734 		case IPV6_2292HOPOPTS:
735 		case IPV6_HOPOPTS:
736 			if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
737 				err = -EINVAL;
738 				goto exit_f;
739 			}
740 
741 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
742 			len = ((hdr->hdrlen + 1) << 3);
743 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
744 				err = -EINVAL;
745 				goto exit_f;
746 			}
747 			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
748 				err = -EPERM;
749 				goto exit_f;
750 			}
751 			opt->opt_nflen += len;
752 			opt->hopopt = hdr;
753 			break;
754 
755 		case IPV6_2292DSTOPTS:
756 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
757 				err = -EINVAL;
758 				goto exit_f;
759 			}
760 
761 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
762 			len = ((hdr->hdrlen + 1) << 3);
763 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
764 				err = -EINVAL;
765 				goto exit_f;
766 			}
767 			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
768 				err = -EPERM;
769 				goto exit_f;
770 			}
771 			if (opt->dst1opt) {
772 				err = -EINVAL;
773 				goto exit_f;
774 			}
775 			opt->opt_flen += len;
776 			opt->dst1opt = hdr;
777 			break;
778 
779 		case IPV6_DSTOPTS:
780 		case IPV6_RTHDRDSTOPTS:
781 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
782 				err = -EINVAL;
783 				goto exit_f;
784 			}
785 
786 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
787 			len = ((hdr->hdrlen + 1) << 3);
788 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
789 				err = -EINVAL;
790 				goto exit_f;
791 			}
792 			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
793 				err = -EPERM;
794 				goto exit_f;
795 			}
796 			if (cmsg->cmsg_type == IPV6_DSTOPTS) {
797 				opt->opt_flen += len;
798 				opt->dst1opt = hdr;
799 			} else {
800 				opt->opt_nflen += len;
801 				opt->dst0opt = hdr;
802 			}
803 			break;
804 
805 		case IPV6_2292RTHDR:
806 		case IPV6_RTHDR:
807 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
808 				err = -EINVAL;
809 				goto exit_f;
810 			}
811 
812 			rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
813 
814 			switch (rthdr->type) {
815 #if IS_ENABLED(CONFIG_IPV6_MIP6)
816 			case IPV6_SRCRT_TYPE_2:
817 				if (rthdr->hdrlen != 2 ||
818 				    rthdr->segments_left != 1) {
819 					err = -EINVAL;
820 					goto exit_f;
821 				}
822 				break;
823 #endif
824 			default:
825 				err = -EINVAL;
826 				goto exit_f;
827 			}
828 
829 			len = ((rthdr->hdrlen + 1) << 3);
830 
831 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
832 				err = -EINVAL;
833 				goto exit_f;
834 			}
835 
836 			/* segments left must also match */
837 			if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
838 				err = -EINVAL;
839 				goto exit_f;
840 			}
841 
842 			opt->opt_nflen += len;
843 			opt->srcrt = rthdr;
844 
845 			if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
846 				int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
847 
848 				opt->opt_nflen += dsthdrlen;
849 				opt->dst0opt = opt->dst1opt;
850 				opt->dst1opt = NULL;
851 				opt->opt_flen -= dsthdrlen;
852 			}
853 
854 			break;
855 
856 		case IPV6_2292HOPLIMIT:
857 		case IPV6_HOPLIMIT:
858 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
859 				err = -EINVAL;
860 				goto exit_f;
861 			}
862 
863 			*hlimit = *(int *)CMSG_DATA(cmsg);
864 			if (*hlimit < -1 || *hlimit > 0xff) {
865 				err = -EINVAL;
866 				goto exit_f;
867 			}
868 
869 			break;
870 
871 		case IPV6_TCLASS:
872 		    {
873 			int tc;
874 
875 			err = -EINVAL;
876 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
877 				goto exit_f;
878 
879 			tc = *(int *)CMSG_DATA(cmsg);
880 			if (tc < -1 || tc > 0xff)
881 				goto exit_f;
882 
883 			err = 0;
884 			*tclass = tc;
885 
886 			break;
887 		    }
888 
889 		case IPV6_DONTFRAG:
890 		    {
891 			int df;
892 
893 			err = -EINVAL;
894 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
895 				goto exit_f;
896 
897 			df = *(int *)CMSG_DATA(cmsg);
898 			if (df < 0 || df > 1)
899 				goto exit_f;
900 
901 			err = 0;
902 			*dontfrag = df;
903 
904 			break;
905 		    }
906 		default:
907 			LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
908 				       cmsg->cmsg_type);
909 			err = -EINVAL;
910 			goto exit_f;
911 		}
912 	}
913 
914 exit_f:
915 	return err;
916 }
917 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
918 
919 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
920 			     __u16 srcp, __u16 destp, int bucket)
921 {
922 	const struct in6_addr *dest, *src;
923 
924 	dest  = &sp->sk_v6_daddr;
925 	src   = &sp->sk_v6_rcv_saddr;
926 	seq_printf(seq,
927 		   "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
928 		   "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
929 		   bucket,
930 		   src->s6_addr32[0], src->s6_addr32[1],
931 		   src->s6_addr32[2], src->s6_addr32[3], srcp,
932 		   dest->s6_addr32[0], dest->s6_addr32[1],
933 		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
934 		   sp->sk_state,
935 		   sk_wmem_alloc_get(sp),
936 		   sk_rmem_alloc_get(sp),
937 		   0, 0L, 0,
938 		   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
939 		   0,
940 		   sock_i_ino(sp),
941 		   atomic_read(&sp->sk_refcnt), sp,
942 		   atomic_read(&sp->sk_drops));
943 }
944