xref: /openbmc/linux/net/ipv6/datagram.c (revision 483eb062)
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 out:
203 	fl6_sock_release(flowlabel);
204 	return err;
205 }
206 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
207 
208 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
209 				 int addr_len)
210 {
211 	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
212 	if (sin6->sin6_family != AF_INET6)
213 		return -EAFNOSUPPORT;
214 	return ip6_datagram_connect(sk, uaddr, addr_len);
215 }
216 EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
217 
218 void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
219 		     __be16 port, u32 info, u8 *payload)
220 {
221 	struct ipv6_pinfo *np  = inet6_sk(sk);
222 	struct icmp6hdr *icmph = icmp6_hdr(skb);
223 	struct sock_exterr_skb *serr;
224 
225 	if (!np->recverr)
226 		return;
227 
228 	skb = skb_clone(skb, GFP_ATOMIC);
229 	if (!skb)
230 		return;
231 
232 	skb->protocol = htons(ETH_P_IPV6);
233 
234 	serr = SKB_EXT_ERR(skb);
235 	serr->ee.ee_errno = err;
236 	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
237 	serr->ee.ee_type = icmph->icmp6_type;
238 	serr->ee.ee_code = icmph->icmp6_code;
239 	serr->ee.ee_pad = 0;
240 	serr->ee.ee_info = info;
241 	serr->ee.ee_data = 0;
242 	serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
243 				  skb_network_header(skb);
244 	serr->port = port;
245 
246 	__skb_pull(skb, payload - skb->data);
247 	skb_reset_transport_header(skb);
248 
249 	if (sock_queue_err_skb(sk, skb))
250 		kfree_skb(skb);
251 }
252 
253 void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
254 {
255 	struct ipv6_pinfo *np = inet6_sk(sk);
256 	struct sock_exterr_skb *serr;
257 	struct ipv6hdr *iph;
258 	struct sk_buff *skb;
259 
260 	if (!np->recverr)
261 		return;
262 
263 	skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
264 	if (!skb)
265 		return;
266 
267 	skb->protocol = htons(ETH_P_IPV6);
268 
269 	skb_put(skb, sizeof(struct ipv6hdr));
270 	skb_reset_network_header(skb);
271 	iph = ipv6_hdr(skb);
272 	iph->daddr = fl6->daddr;
273 
274 	serr = SKB_EXT_ERR(skb);
275 	serr->ee.ee_errno = err;
276 	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
277 	serr->ee.ee_type = 0;
278 	serr->ee.ee_code = 0;
279 	serr->ee.ee_pad = 0;
280 	serr->ee.ee_info = info;
281 	serr->ee.ee_data = 0;
282 	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
283 	serr->port = fl6->fl6_dport;
284 
285 	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
286 	skb_reset_transport_header(skb);
287 
288 	if (sock_queue_err_skb(sk, skb))
289 		kfree_skb(skb);
290 }
291 
292 void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
293 {
294 	struct ipv6_pinfo *np = inet6_sk(sk);
295 	struct ipv6hdr *iph;
296 	struct sk_buff *skb;
297 	struct ip6_mtuinfo *mtu_info;
298 
299 	if (!np->rxopt.bits.rxpmtu)
300 		return;
301 
302 	skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
303 	if (!skb)
304 		return;
305 
306 	skb_put(skb, sizeof(struct ipv6hdr));
307 	skb_reset_network_header(skb);
308 	iph = ipv6_hdr(skb);
309 	iph->daddr = fl6->daddr;
310 
311 	mtu_info = IP6CBMTU(skb);
312 
313 	mtu_info->ip6m_mtu = mtu;
314 	mtu_info->ip6m_addr.sin6_family = AF_INET6;
315 	mtu_info->ip6m_addr.sin6_port = 0;
316 	mtu_info->ip6m_addr.sin6_flowinfo = 0;
317 	mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
318 	mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
319 
320 	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
321 	skb_reset_transport_header(skb);
322 
323 	skb = xchg(&np->rxpmtu, skb);
324 	kfree_skb(skb);
325 }
326 
327 /*
328  *	Handle MSG_ERRQUEUE
329  */
330 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
331 {
332 	struct ipv6_pinfo *np = inet6_sk(sk);
333 	struct sock_exterr_skb *serr;
334 	struct sk_buff *skb, *skb2;
335 	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
336 	struct {
337 		struct sock_extended_err ee;
338 		struct sockaddr_in6	 offender;
339 	} errhdr;
340 	int err;
341 	int copied;
342 
343 	err = -EAGAIN;
344 	skb = skb_dequeue(&sk->sk_error_queue);
345 	if (skb == NULL)
346 		goto out;
347 
348 	copied = skb->len;
349 	if (copied > len) {
350 		msg->msg_flags |= MSG_TRUNC;
351 		copied = len;
352 	}
353 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
354 	if (err)
355 		goto out_free_skb;
356 
357 	sock_recv_timestamp(msg, sk, skb);
358 
359 	serr = SKB_EXT_ERR(skb);
360 
361 	if (sin) {
362 		const unsigned char *nh = skb_network_header(skb);
363 		sin->sin6_family = AF_INET6;
364 		sin->sin6_flowinfo = 0;
365 		sin->sin6_port = serr->port;
366 		if (skb->protocol == htons(ETH_P_IPV6)) {
367 			const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
368 								  struct ipv6hdr, daddr);
369 			sin->sin6_addr = ip6h->daddr;
370 			if (np->sndflow)
371 				sin->sin6_flowinfo = ip6_flowinfo(ip6h);
372 			sin->sin6_scope_id =
373 				ipv6_iface_scope_id(&sin->sin6_addr,
374 						    IP6CB(skb)->iif);
375 		} else {
376 			ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
377 					       &sin->sin6_addr);
378 			sin->sin6_scope_id = 0;
379 		}
380 		*addr_len = sizeof(*sin);
381 	}
382 
383 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
384 	sin = &errhdr.offender;
385 	sin->sin6_family = AF_UNSPEC;
386 	if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
387 		sin->sin6_family = AF_INET6;
388 		sin->sin6_flowinfo = 0;
389 		sin->sin6_port = 0;
390 		if (np->rxopt.all)
391 			ip6_datagram_recv_common_ctl(sk, msg, skb);
392 		if (skb->protocol == htons(ETH_P_IPV6)) {
393 			sin->sin6_addr = ipv6_hdr(skb)->saddr;
394 			if (np->rxopt.all)
395 				ip6_datagram_recv_specific_ctl(sk, msg, skb);
396 			sin->sin6_scope_id =
397 				ipv6_iface_scope_id(&sin->sin6_addr,
398 						    IP6CB(skb)->iif);
399 		} else {
400 			struct inet_sock *inet = inet_sk(sk);
401 
402 			ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
403 					       &sin->sin6_addr);
404 			sin->sin6_scope_id = 0;
405 			if (inet->cmsg_flags)
406 				ip_cmsg_recv(msg, skb);
407 		}
408 	}
409 
410 	put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
411 
412 	/* Now we could try to dump offended packet options */
413 
414 	msg->msg_flags |= MSG_ERRQUEUE;
415 	err = copied;
416 
417 	/* Reset and regenerate socket error */
418 	spin_lock_bh(&sk->sk_error_queue.lock);
419 	sk->sk_err = 0;
420 	if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
421 		sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
422 		spin_unlock_bh(&sk->sk_error_queue.lock);
423 		sk->sk_error_report(sk);
424 	} else {
425 		spin_unlock_bh(&sk->sk_error_queue.lock);
426 	}
427 
428 out_free_skb:
429 	kfree_skb(skb);
430 out:
431 	return err;
432 }
433 EXPORT_SYMBOL_GPL(ipv6_recv_error);
434 
435 /*
436  *	Handle IPV6_RECVPATHMTU
437  */
438 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
439 		     int *addr_len)
440 {
441 	struct ipv6_pinfo *np = inet6_sk(sk);
442 	struct sk_buff *skb;
443 	struct ip6_mtuinfo mtu_info;
444 	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
445 	int err;
446 	int copied;
447 
448 	err = -EAGAIN;
449 	skb = xchg(&np->rxpmtu, NULL);
450 	if (skb == NULL)
451 		goto out;
452 
453 	copied = skb->len;
454 	if (copied > len) {
455 		msg->msg_flags |= MSG_TRUNC;
456 		copied = len;
457 	}
458 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
459 	if (err)
460 		goto out_free_skb;
461 
462 	sock_recv_timestamp(msg, sk, skb);
463 
464 	memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
465 
466 	if (sin) {
467 		sin->sin6_family = AF_INET6;
468 		sin->sin6_flowinfo = 0;
469 		sin->sin6_port = 0;
470 		sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
471 		sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
472 		*addr_len = sizeof(*sin);
473 	}
474 
475 	put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
476 
477 	err = copied;
478 
479 out_free_skb:
480 	kfree_skb(skb);
481 out:
482 	return err;
483 }
484 
485 
486 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
487 				 struct sk_buff *skb)
488 {
489 	struct ipv6_pinfo *np = inet6_sk(sk);
490 	bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
491 
492 	if (np->rxopt.bits.rxinfo) {
493 		struct in6_pktinfo src_info;
494 
495 		if (is_ipv6) {
496 			src_info.ipi6_ifindex = IP6CB(skb)->iif;
497 			src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
498 		} else {
499 			src_info.ipi6_ifindex =
500 				PKTINFO_SKB_CB(skb)->ipi_ifindex;
501 			ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
502 					       &src_info.ipi6_addr);
503 		}
504 		put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
505 	}
506 }
507 
508 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
509 				    struct sk_buff *skb)
510 {
511 	struct ipv6_pinfo *np = inet6_sk(sk);
512 	struct inet6_skb_parm *opt = IP6CB(skb);
513 	unsigned char *nh = skb_network_header(skb);
514 
515 	if (np->rxopt.bits.rxhlim) {
516 		int hlim = ipv6_hdr(skb)->hop_limit;
517 		put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
518 	}
519 
520 	if (np->rxopt.bits.rxtclass) {
521 		int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
522 		put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
523 	}
524 
525 	if (np->rxopt.bits.rxflow) {
526 		__be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
527 		if (flowinfo)
528 			put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
529 	}
530 
531 	/* HbH is allowed only once */
532 	if (np->rxopt.bits.hopopts && opt->hop) {
533 		u8 *ptr = nh + opt->hop;
534 		put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
535 	}
536 
537 	if (opt->lastopt &&
538 	    (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
539 		/*
540 		 * Silly enough, but we need to reparse in order to
541 		 * report extension headers (except for HbH)
542 		 * in order.
543 		 *
544 		 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
545 		 * (and WILL NOT be) defined because
546 		 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
547 		 */
548 		unsigned int off = sizeof(struct ipv6hdr);
549 		u8 nexthdr = ipv6_hdr(skb)->nexthdr;
550 
551 		while (off <= opt->lastopt) {
552 			unsigned int len;
553 			u8 *ptr = nh + off;
554 
555 			switch (nexthdr) {
556 			case IPPROTO_DSTOPTS:
557 				nexthdr = ptr[0];
558 				len = (ptr[1] + 1) << 3;
559 				if (np->rxopt.bits.dstopts)
560 					put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
561 				break;
562 			case IPPROTO_ROUTING:
563 				nexthdr = ptr[0];
564 				len = (ptr[1] + 1) << 3;
565 				if (np->rxopt.bits.srcrt)
566 					put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
567 				break;
568 			case IPPROTO_AH:
569 				nexthdr = ptr[0];
570 				len = (ptr[1] + 2) << 2;
571 				break;
572 			default:
573 				nexthdr = ptr[0];
574 				len = (ptr[1] + 1) << 3;
575 				break;
576 			}
577 
578 			off += len;
579 		}
580 	}
581 
582 	/* socket options in old style */
583 	if (np->rxopt.bits.rxoinfo) {
584 		struct in6_pktinfo src_info;
585 
586 		src_info.ipi6_ifindex = opt->iif;
587 		src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
588 		put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
589 	}
590 	if (np->rxopt.bits.rxohlim) {
591 		int hlim = ipv6_hdr(skb)->hop_limit;
592 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
593 	}
594 	if (np->rxopt.bits.ohopopts && opt->hop) {
595 		u8 *ptr = nh + opt->hop;
596 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
597 	}
598 	if (np->rxopt.bits.odstopts && opt->dst0) {
599 		u8 *ptr = nh + opt->dst0;
600 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
601 	}
602 	if (np->rxopt.bits.osrcrt && opt->srcrt) {
603 		struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
604 		put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
605 	}
606 	if (np->rxopt.bits.odstopts && opt->dst1) {
607 		u8 *ptr = nh + opt->dst1;
608 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
609 	}
610 	if (np->rxopt.bits.rxorigdstaddr) {
611 		struct sockaddr_in6 sin6;
612 		__be16 *ports = (__be16 *) skb_transport_header(skb);
613 
614 		if (skb_transport_offset(skb) + 4 <= skb->len) {
615 			/* All current transport protocols have the port numbers in the
616 			 * first four bytes of the transport header and this function is
617 			 * written with this assumption in mind.
618 			 */
619 
620 			sin6.sin6_family = AF_INET6;
621 			sin6.sin6_addr = ipv6_hdr(skb)->daddr;
622 			sin6.sin6_port = ports[1];
623 			sin6.sin6_flowinfo = 0;
624 			sin6.sin6_scope_id =
625 				ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
626 						    opt->iif);
627 
628 			put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
629 		}
630 	}
631 }
632 
633 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
634 			  struct sk_buff *skb)
635 {
636 	ip6_datagram_recv_common_ctl(sk, msg, skb);
637 	ip6_datagram_recv_specific_ctl(sk, msg, skb);
638 }
639 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
640 
641 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
642 			  struct msghdr *msg, struct flowi6 *fl6,
643 			  struct ipv6_txoptions *opt,
644 			  int *hlimit, int *tclass, int *dontfrag)
645 {
646 	struct in6_pktinfo *src_info;
647 	struct cmsghdr *cmsg;
648 	struct ipv6_rt_hdr *rthdr;
649 	struct ipv6_opt_hdr *hdr;
650 	int len;
651 	int err = 0;
652 
653 	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
654 		int addr_type;
655 
656 		if (!CMSG_OK(msg, cmsg)) {
657 			err = -EINVAL;
658 			goto exit_f;
659 		}
660 
661 		if (cmsg->cmsg_level != SOL_IPV6)
662 			continue;
663 
664 		switch (cmsg->cmsg_type) {
665 		case IPV6_PKTINFO:
666 		case IPV6_2292PKTINFO:
667 		    {
668 			struct net_device *dev = NULL;
669 
670 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
671 				err = -EINVAL;
672 				goto exit_f;
673 			}
674 
675 			src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
676 
677 			if (src_info->ipi6_ifindex) {
678 				if (fl6->flowi6_oif &&
679 				    src_info->ipi6_ifindex != fl6->flowi6_oif)
680 					return -EINVAL;
681 				fl6->flowi6_oif = src_info->ipi6_ifindex;
682 			}
683 
684 			addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
685 
686 			rcu_read_lock();
687 			if (fl6->flowi6_oif) {
688 				dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
689 				if (!dev) {
690 					rcu_read_unlock();
691 					return -ENODEV;
692 				}
693 			} else if (addr_type & IPV6_ADDR_LINKLOCAL) {
694 				rcu_read_unlock();
695 				return -EINVAL;
696 			}
697 
698 			if (addr_type != IPV6_ADDR_ANY) {
699 				int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
700 				if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
701 				    !ipv6_chk_addr(net, &src_info->ipi6_addr,
702 						   strict ? dev : NULL, 0) &&
703 				    !ipv6_chk_acast_addr_src(net, dev,
704 							     &src_info->ipi6_addr))
705 					err = -EINVAL;
706 				else
707 					fl6->saddr = src_info->ipi6_addr;
708 			}
709 
710 			rcu_read_unlock();
711 
712 			if (err)
713 				goto exit_f;
714 
715 			break;
716 		    }
717 
718 		case IPV6_FLOWINFO:
719 			if (cmsg->cmsg_len < CMSG_LEN(4)) {
720 				err = -EINVAL;
721 				goto exit_f;
722 			}
723 
724 			if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
725 				if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
726 					err = -EINVAL;
727 					goto exit_f;
728 				}
729 			}
730 			fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
731 			break;
732 
733 		case IPV6_2292HOPOPTS:
734 		case IPV6_HOPOPTS:
735 			if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
736 				err = -EINVAL;
737 				goto exit_f;
738 			}
739 
740 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
741 			len = ((hdr->hdrlen + 1) << 3);
742 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
743 				err = -EINVAL;
744 				goto exit_f;
745 			}
746 			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
747 				err = -EPERM;
748 				goto exit_f;
749 			}
750 			opt->opt_nflen += len;
751 			opt->hopopt = hdr;
752 			break;
753 
754 		case IPV6_2292DSTOPTS:
755 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
756 				err = -EINVAL;
757 				goto exit_f;
758 			}
759 
760 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
761 			len = ((hdr->hdrlen + 1) << 3);
762 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
763 				err = -EINVAL;
764 				goto exit_f;
765 			}
766 			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
767 				err = -EPERM;
768 				goto exit_f;
769 			}
770 			if (opt->dst1opt) {
771 				err = -EINVAL;
772 				goto exit_f;
773 			}
774 			opt->opt_flen += len;
775 			opt->dst1opt = hdr;
776 			break;
777 
778 		case IPV6_DSTOPTS:
779 		case IPV6_RTHDRDSTOPTS:
780 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
781 				err = -EINVAL;
782 				goto exit_f;
783 			}
784 
785 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
786 			len = ((hdr->hdrlen + 1) << 3);
787 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
788 				err = -EINVAL;
789 				goto exit_f;
790 			}
791 			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
792 				err = -EPERM;
793 				goto exit_f;
794 			}
795 			if (cmsg->cmsg_type == IPV6_DSTOPTS) {
796 				opt->opt_flen += len;
797 				opt->dst1opt = hdr;
798 			} else {
799 				opt->opt_nflen += len;
800 				opt->dst0opt = hdr;
801 			}
802 			break;
803 
804 		case IPV6_2292RTHDR:
805 		case IPV6_RTHDR:
806 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
807 				err = -EINVAL;
808 				goto exit_f;
809 			}
810 
811 			rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
812 
813 			switch (rthdr->type) {
814 #if IS_ENABLED(CONFIG_IPV6_MIP6)
815 			case IPV6_SRCRT_TYPE_2:
816 				if (rthdr->hdrlen != 2 ||
817 				    rthdr->segments_left != 1) {
818 					err = -EINVAL;
819 					goto exit_f;
820 				}
821 				break;
822 #endif
823 			default:
824 				err = -EINVAL;
825 				goto exit_f;
826 			}
827 
828 			len = ((rthdr->hdrlen + 1) << 3);
829 
830 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
831 				err = -EINVAL;
832 				goto exit_f;
833 			}
834 
835 			/* segments left must also match */
836 			if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
837 				err = -EINVAL;
838 				goto exit_f;
839 			}
840 
841 			opt->opt_nflen += len;
842 			opt->srcrt = rthdr;
843 
844 			if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
845 				int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
846 
847 				opt->opt_nflen += dsthdrlen;
848 				opt->dst0opt = opt->dst1opt;
849 				opt->dst1opt = NULL;
850 				opt->opt_flen -= dsthdrlen;
851 			}
852 
853 			break;
854 
855 		case IPV6_2292HOPLIMIT:
856 		case IPV6_HOPLIMIT:
857 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
858 				err = -EINVAL;
859 				goto exit_f;
860 			}
861 
862 			*hlimit = *(int *)CMSG_DATA(cmsg);
863 			if (*hlimit < -1 || *hlimit > 0xff) {
864 				err = -EINVAL;
865 				goto exit_f;
866 			}
867 
868 			break;
869 
870 		case IPV6_TCLASS:
871 		    {
872 			int tc;
873 
874 			err = -EINVAL;
875 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
876 				goto exit_f;
877 
878 			tc = *(int *)CMSG_DATA(cmsg);
879 			if (tc < -1 || tc > 0xff)
880 				goto exit_f;
881 
882 			err = 0;
883 			*tclass = tc;
884 
885 			break;
886 		    }
887 
888 		case IPV6_DONTFRAG:
889 		    {
890 			int df;
891 
892 			err = -EINVAL;
893 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
894 				goto exit_f;
895 
896 			df = *(int *)CMSG_DATA(cmsg);
897 			if (df < 0 || df > 1)
898 				goto exit_f;
899 
900 			err = 0;
901 			*dontfrag = df;
902 
903 			break;
904 		    }
905 		default:
906 			LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
907 				       cmsg->cmsg_type);
908 			err = -EINVAL;
909 			goto exit_f;
910 		}
911 	}
912 
913 exit_f:
914 	return err;
915 }
916 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
917 
918 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
919 			     __u16 srcp, __u16 destp, int bucket)
920 {
921 	const struct in6_addr *dest, *src;
922 
923 	dest  = &sp->sk_v6_daddr;
924 	src   = &sp->sk_v6_rcv_saddr;
925 	seq_printf(seq,
926 		   "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
927 		   "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
928 		   bucket,
929 		   src->s6_addr32[0], src->s6_addr32[1],
930 		   src->s6_addr32[2], src->s6_addr32[3], srcp,
931 		   dest->s6_addr32[0], dest->s6_addr32[1],
932 		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
933 		   sp->sk_state,
934 		   sk_wmem_alloc_get(sp),
935 		   sk_rmem_alloc_get(sp),
936 		   0, 0L, 0,
937 		   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
938 		   0,
939 		   sock_i_ino(sp),
940 		   atomic_read(&sp->sk_refcnt), sp,
941 		   atomic_read(&sp->sk_drops));
942 }
943