xref: /openbmc/linux/net/ipv6/datagram.c (revision c819e2cf)
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 static void ip6_datagram_prepare_pktinfo_errqueue(struct sk_buff *skb)
329 {
330 	int ifindex = skb->dev ? skb->dev->ifindex : -1;
331 
332 	if (skb->protocol == htons(ETH_P_IPV6))
333 		IP6CB(skb)->iif = ifindex;
334 	else
335 		PKTINFO_SKB_CB(skb)->ipi_ifindex = ifindex;
336 }
337 
338 /*
339  *	Handle MSG_ERRQUEUE
340  */
341 int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
342 {
343 	struct ipv6_pinfo *np = inet6_sk(sk);
344 	struct sock_exterr_skb *serr;
345 	struct sk_buff *skb;
346 	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
347 	struct {
348 		struct sock_extended_err ee;
349 		struct sockaddr_in6	 offender;
350 	} errhdr;
351 	int err;
352 	int copied;
353 
354 	err = -EAGAIN;
355 	skb = sock_dequeue_err_skb(sk);
356 	if (skb == NULL)
357 		goto out;
358 
359 	copied = skb->len;
360 	if (copied > len) {
361 		msg->msg_flags |= MSG_TRUNC;
362 		copied = len;
363 	}
364 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
365 	if (err)
366 		goto out_free_skb;
367 
368 	sock_recv_timestamp(msg, sk, skb);
369 
370 	serr = SKB_EXT_ERR(skb);
371 
372 	if (sin) {
373 		const unsigned char *nh = skb_network_header(skb);
374 		sin->sin6_family = AF_INET6;
375 		sin->sin6_flowinfo = 0;
376 		sin->sin6_port = serr->port;
377 		if (skb->protocol == htons(ETH_P_IPV6)) {
378 			const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
379 								  struct ipv6hdr, daddr);
380 			sin->sin6_addr = ip6h->daddr;
381 			if (np->sndflow)
382 				sin->sin6_flowinfo = ip6_flowinfo(ip6h);
383 			sin->sin6_scope_id =
384 				ipv6_iface_scope_id(&sin->sin6_addr,
385 						    IP6CB(skb)->iif);
386 		} else {
387 			ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
388 					       &sin->sin6_addr);
389 			sin->sin6_scope_id = 0;
390 		}
391 		*addr_len = sizeof(*sin);
392 	}
393 
394 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
395 	sin = &errhdr.offender;
396 	memset(sin, 0, sizeof(*sin));
397 
398 	if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
399 		sin->sin6_family = AF_INET6;
400 		if (np->rxopt.all) {
401 			if (serr->ee.ee_origin != SO_EE_ORIGIN_ICMP &&
402 			    serr->ee.ee_origin != SO_EE_ORIGIN_ICMP6)
403 				ip6_datagram_prepare_pktinfo_errqueue(skb);
404 			ip6_datagram_recv_common_ctl(sk, msg, skb);
405 		}
406 		if (skb->protocol == htons(ETH_P_IPV6)) {
407 			sin->sin6_addr = ipv6_hdr(skb)->saddr;
408 			if (np->rxopt.all)
409 				ip6_datagram_recv_specific_ctl(sk, msg, skb);
410 			sin->sin6_scope_id =
411 				ipv6_iface_scope_id(&sin->sin6_addr,
412 						    IP6CB(skb)->iif);
413 		} else {
414 			ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
415 					       &sin->sin6_addr);
416 			if (inet_sk(sk)->cmsg_flags)
417 				ip_cmsg_recv(msg, skb);
418 		}
419 	}
420 
421 	put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
422 
423 	/* Now we could try to dump offended packet options */
424 
425 	msg->msg_flags |= MSG_ERRQUEUE;
426 	err = copied;
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_msg(skb, 0, msg, 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 
505 		if (src_info.ipi6_ifindex >= 0)
506 			put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
507 				 sizeof(src_info), &src_info);
508 	}
509 }
510 
511 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
512 				    struct sk_buff *skb)
513 {
514 	struct ipv6_pinfo *np = inet6_sk(sk);
515 	struct inet6_skb_parm *opt = IP6CB(skb);
516 	unsigned char *nh = skb_network_header(skb);
517 
518 	if (np->rxopt.bits.rxhlim) {
519 		int hlim = ipv6_hdr(skb)->hop_limit;
520 		put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
521 	}
522 
523 	if (np->rxopt.bits.rxtclass) {
524 		int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
525 		put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
526 	}
527 
528 	if (np->rxopt.bits.rxflow) {
529 		__be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
530 		if (flowinfo)
531 			put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
532 	}
533 
534 	/* HbH is allowed only once */
535 	if (np->rxopt.bits.hopopts && opt->hop) {
536 		u8 *ptr = nh + opt->hop;
537 		put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
538 	}
539 
540 	if (opt->lastopt &&
541 	    (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
542 		/*
543 		 * Silly enough, but we need to reparse in order to
544 		 * report extension headers (except for HbH)
545 		 * in order.
546 		 *
547 		 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
548 		 * (and WILL NOT be) defined because
549 		 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
550 		 */
551 		unsigned int off = sizeof(struct ipv6hdr);
552 		u8 nexthdr = ipv6_hdr(skb)->nexthdr;
553 
554 		while (off <= opt->lastopt) {
555 			unsigned int len;
556 			u8 *ptr = nh + off;
557 
558 			switch (nexthdr) {
559 			case IPPROTO_DSTOPTS:
560 				nexthdr = ptr[0];
561 				len = (ptr[1] + 1) << 3;
562 				if (np->rxopt.bits.dstopts)
563 					put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
564 				break;
565 			case IPPROTO_ROUTING:
566 				nexthdr = ptr[0];
567 				len = (ptr[1] + 1) << 3;
568 				if (np->rxopt.bits.srcrt)
569 					put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
570 				break;
571 			case IPPROTO_AH:
572 				nexthdr = ptr[0];
573 				len = (ptr[1] + 2) << 2;
574 				break;
575 			default:
576 				nexthdr = ptr[0];
577 				len = (ptr[1] + 1) << 3;
578 				break;
579 			}
580 
581 			off += len;
582 		}
583 	}
584 
585 	/* socket options in old style */
586 	if (np->rxopt.bits.rxoinfo) {
587 		struct in6_pktinfo src_info;
588 
589 		src_info.ipi6_ifindex = opt->iif;
590 		src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
591 		put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
592 	}
593 	if (np->rxopt.bits.rxohlim) {
594 		int hlim = ipv6_hdr(skb)->hop_limit;
595 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
596 	}
597 	if (np->rxopt.bits.ohopopts && opt->hop) {
598 		u8 *ptr = nh + opt->hop;
599 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
600 	}
601 	if (np->rxopt.bits.odstopts && opt->dst0) {
602 		u8 *ptr = nh + opt->dst0;
603 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
604 	}
605 	if (np->rxopt.bits.osrcrt && opt->srcrt) {
606 		struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
607 		put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
608 	}
609 	if (np->rxopt.bits.odstopts && opt->dst1) {
610 		u8 *ptr = nh + opt->dst1;
611 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
612 	}
613 	if (np->rxopt.bits.rxorigdstaddr) {
614 		struct sockaddr_in6 sin6;
615 		__be16 *ports = (__be16 *) skb_transport_header(skb);
616 
617 		if (skb_transport_offset(skb) + 4 <= skb->len) {
618 			/* All current transport protocols have the port numbers in the
619 			 * first four bytes of the transport header and this function is
620 			 * written with this assumption in mind.
621 			 */
622 
623 			sin6.sin6_family = AF_INET6;
624 			sin6.sin6_addr = ipv6_hdr(skb)->daddr;
625 			sin6.sin6_port = ports[1];
626 			sin6.sin6_flowinfo = 0;
627 			sin6.sin6_scope_id =
628 				ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
629 						    opt->iif);
630 
631 			put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
632 		}
633 	}
634 }
635 
636 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
637 			  struct sk_buff *skb)
638 {
639 	ip6_datagram_recv_common_ctl(sk, msg, skb);
640 	ip6_datagram_recv_specific_ctl(sk, msg, skb);
641 }
642 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
643 
644 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
645 			  struct msghdr *msg, struct flowi6 *fl6,
646 			  struct ipv6_txoptions *opt,
647 			  int *hlimit, int *tclass, int *dontfrag)
648 {
649 	struct in6_pktinfo *src_info;
650 	struct cmsghdr *cmsg;
651 	struct ipv6_rt_hdr *rthdr;
652 	struct ipv6_opt_hdr *hdr;
653 	int len;
654 	int err = 0;
655 
656 	for_each_cmsghdr(cmsg, msg) {
657 		int addr_type;
658 
659 		if (!CMSG_OK(msg, cmsg)) {
660 			err = -EINVAL;
661 			goto exit_f;
662 		}
663 
664 		if (cmsg->cmsg_level != SOL_IPV6)
665 			continue;
666 
667 		switch (cmsg->cmsg_type) {
668 		case IPV6_PKTINFO:
669 		case IPV6_2292PKTINFO:
670 		    {
671 			struct net_device *dev = NULL;
672 
673 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
674 				err = -EINVAL;
675 				goto exit_f;
676 			}
677 
678 			src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
679 
680 			if (src_info->ipi6_ifindex) {
681 				if (fl6->flowi6_oif &&
682 				    src_info->ipi6_ifindex != fl6->flowi6_oif)
683 					return -EINVAL;
684 				fl6->flowi6_oif = src_info->ipi6_ifindex;
685 			}
686 
687 			addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
688 
689 			rcu_read_lock();
690 			if (fl6->flowi6_oif) {
691 				dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
692 				if (!dev) {
693 					rcu_read_unlock();
694 					return -ENODEV;
695 				}
696 			} else if (addr_type & IPV6_ADDR_LINKLOCAL) {
697 				rcu_read_unlock();
698 				return -EINVAL;
699 			}
700 
701 			if (addr_type != IPV6_ADDR_ANY) {
702 				int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
703 				if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
704 				    !ipv6_chk_addr(net, &src_info->ipi6_addr,
705 						   strict ? dev : NULL, 0) &&
706 				    !ipv6_chk_acast_addr_src(net, dev,
707 							     &src_info->ipi6_addr))
708 					err = -EINVAL;
709 				else
710 					fl6->saddr = src_info->ipi6_addr;
711 			}
712 
713 			rcu_read_unlock();
714 
715 			if (err)
716 				goto exit_f;
717 
718 			break;
719 		    }
720 
721 		case IPV6_FLOWINFO:
722 			if (cmsg->cmsg_len < CMSG_LEN(4)) {
723 				err = -EINVAL;
724 				goto exit_f;
725 			}
726 
727 			if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
728 				if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
729 					err = -EINVAL;
730 					goto exit_f;
731 				}
732 			}
733 			fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
734 			break;
735 
736 		case IPV6_2292HOPOPTS:
737 		case IPV6_HOPOPTS:
738 			if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
739 				err = -EINVAL;
740 				goto exit_f;
741 			}
742 
743 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
744 			len = ((hdr->hdrlen + 1) << 3);
745 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
746 				err = -EINVAL;
747 				goto exit_f;
748 			}
749 			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
750 				err = -EPERM;
751 				goto exit_f;
752 			}
753 			opt->opt_nflen += len;
754 			opt->hopopt = hdr;
755 			break;
756 
757 		case IPV6_2292DSTOPTS:
758 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
759 				err = -EINVAL;
760 				goto exit_f;
761 			}
762 
763 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
764 			len = ((hdr->hdrlen + 1) << 3);
765 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
766 				err = -EINVAL;
767 				goto exit_f;
768 			}
769 			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
770 				err = -EPERM;
771 				goto exit_f;
772 			}
773 			if (opt->dst1opt) {
774 				err = -EINVAL;
775 				goto exit_f;
776 			}
777 			opt->opt_flen += len;
778 			opt->dst1opt = hdr;
779 			break;
780 
781 		case IPV6_DSTOPTS:
782 		case IPV6_RTHDRDSTOPTS:
783 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
784 				err = -EINVAL;
785 				goto exit_f;
786 			}
787 
788 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
789 			len = ((hdr->hdrlen + 1) << 3);
790 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
791 				err = -EINVAL;
792 				goto exit_f;
793 			}
794 			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
795 				err = -EPERM;
796 				goto exit_f;
797 			}
798 			if (cmsg->cmsg_type == IPV6_DSTOPTS) {
799 				opt->opt_flen += len;
800 				opt->dst1opt = hdr;
801 			} else {
802 				opt->opt_nflen += len;
803 				opt->dst0opt = hdr;
804 			}
805 			break;
806 
807 		case IPV6_2292RTHDR:
808 		case IPV6_RTHDR:
809 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
810 				err = -EINVAL;
811 				goto exit_f;
812 			}
813 
814 			rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
815 
816 			switch (rthdr->type) {
817 #if IS_ENABLED(CONFIG_IPV6_MIP6)
818 			case IPV6_SRCRT_TYPE_2:
819 				if (rthdr->hdrlen != 2 ||
820 				    rthdr->segments_left != 1) {
821 					err = -EINVAL;
822 					goto exit_f;
823 				}
824 				break;
825 #endif
826 			default:
827 				err = -EINVAL;
828 				goto exit_f;
829 			}
830 
831 			len = ((rthdr->hdrlen + 1) << 3);
832 
833 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
834 				err = -EINVAL;
835 				goto exit_f;
836 			}
837 
838 			/* segments left must also match */
839 			if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
840 				err = -EINVAL;
841 				goto exit_f;
842 			}
843 
844 			opt->opt_nflen += len;
845 			opt->srcrt = rthdr;
846 
847 			if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
848 				int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
849 
850 				opt->opt_nflen += dsthdrlen;
851 				opt->dst0opt = opt->dst1opt;
852 				opt->dst1opt = NULL;
853 				opt->opt_flen -= dsthdrlen;
854 			}
855 
856 			break;
857 
858 		case IPV6_2292HOPLIMIT:
859 		case IPV6_HOPLIMIT:
860 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
861 				err = -EINVAL;
862 				goto exit_f;
863 			}
864 
865 			*hlimit = *(int *)CMSG_DATA(cmsg);
866 			if (*hlimit < -1 || *hlimit > 0xff) {
867 				err = -EINVAL;
868 				goto exit_f;
869 			}
870 
871 			break;
872 
873 		case IPV6_TCLASS:
874 		    {
875 			int tc;
876 
877 			err = -EINVAL;
878 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
879 				goto exit_f;
880 
881 			tc = *(int *)CMSG_DATA(cmsg);
882 			if (tc < -1 || tc > 0xff)
883 				goto exit_f;
884 
885 			err = 0;
886 			*tclass = tc;
887 
888 			break;
889 		    }
890 
891 		case IPV6_DONTFRAG:
892 		    {
893 			int df;
894 
895 			err = -EINVAL;
896 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
897 				goto exit_f;
898 
899 			df = *(int *)CMSG_DATA(cmsg);
900 			if (df < 0 || df > 1)
901 				goto exit_f;
902 
903 			err = 0;
904 			*dontfrag = df;
905 
906 			break;
907 		    }
908 		default:
909 			net_dbg_ratelimited("invalid cmsg type: %d\n",
910 					    cmsg->cmsg_type);
911 			err = -EINVAL;
912 			goto exit_f;
913 		}
914 	}
915 
916 exit_f:
917 	return err;
918 }
919 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
920 
921 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
922 			     __u16 srcp, __u16 destp, int bucket)
923 {
924 	const struct in6_addr *dest, *src;
925 
926 	dest  = &sp->sk_v6_daddr;
927 	src   = &sp->sk_v6_rcv_saddr;
928 	seq_printf(seq,
929 		   "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
930 		   "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
931 		   bucket,
932 		   src->s6_addr32[0], src->s6_addr32[1],
933 		   src->s6_addr32[2], src->s6_addr32[3], srcp,
934 		   dest->s6_addr32[0], dest->s6_addr32[1],
935 		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
936 		   sp->sk_state,
937 		   sk_wmem_alloc_get(sp),
938 		   sk_rmem_alloc_get(sp),
939 		   0, 0L, 0,
940 		   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
941 		   0,
942 		   sock_i_ino(sp),
943 		   atomic_read(&sp->sk_refcnt), sp,
944 		   atomic_read(&sp->sk_drops));
945 }
946