xref: /openbmc/linux/net/ipv6/datagram.c (revision 8684014d)
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 	sin->sin6_family = AF_UNSPEC;
397 	if (serr->ee.ee_origin != SO_EE_ORIGIN_LOCAL) {
398 		sin->sin6_family = AF_INET6;
399 		sin->sin6_flowinfo = 0;
400 		sin->sin6_port = 0;
401 		if (np->rxopt.all) {
402 			if (serr->ee.ee_origin != SO_EE_ORIGIN_ICMP &&
403 			    serr->ee.ee_origin != SO_EE_ORIGIN_ICMP6)
404 				ip6_datagram_prepare_pktinfo_errqueue(skb);
405 			ip6_datagram_recv_common_ctl(sk, msg, skb);
406 		}
407 		if (skb->protocol == htons(ETH_P_IPV6)) {
408 			sin->sin6_addr = ipv6_hdr(skb)->saddr;
409 			if (np->rxopt.all)
410 				ip6_datagram_recv_specific_ctl(sk, msg, skb);
411 			sin->sin6_scope_id =
412 				ipv6_iface_scope_id(&sin->sin6_addr,
413 						    IP6CB(skb)->iif);
414 		} else {
415 			struct inet_sock *inet = inet_sk(sk);
416 
417 			ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
418 					       &sin->sin6_addr);
419 			sin->sin6_scope_id = 0;
420 			if (inet->cmsg_flags)
421 				ip_cmsg_recv(msg, skb);
422 		}
423 	}
424 
425 	put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
426 
427 	/* Now we could try to dump offended packet options */
428 
429 	msg->msg_flags |= MSG_ERRQUEUE;
430 	err = copied;
431 
432 out_free_skb:
433 	kfree_skb(skb);
434 out:
435 	return err;
436 }
437 EXPORT_SYMBOL_GPL(ipv6_recv_error);
438 
439 /*
440  *	Handle IPV6_RECVPATHMTU
441  */
442 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
443 		     int *addr_len)
444 {
445 	struct ipv6_pinfo *np = inet6_sk(sk);
446 	struct sk_buff *skb;
447 	struct ip6_mtuinfo mtu_info;
448 	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
449 	int err;
450 	int copied;
451 
452 	err = -EAGAIN;
453 	skb = xchg(&np->rxpmtu, NULL);
454 	if (skb == NULL)
455 		goto out;
456 
457 	copied = skb->len;
458 	if (copied > len) {
459 		msg->msg_flags |= MSG_TRUNC;
460 		copied = len;
461 	}
462 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
463 	if (err)
464 		goto out_free_skb;
465 
466 	sock_recv_timestamp(msg, sk, skb);
467 
468 	memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
469 
470 	if (sin) {
471 		sin->sin6_family = AF_INET6;
472 		sin->sin6_flowinfo = 0;
473 		sin->sin6_port = 0;
474 		sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
475 		sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
476 		*addr_len = sizeof(*sin);
477 	}
478 
479 	put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
480 
481 	err = copied;
482 
483 out_free_skb:
484 	kfree_skb(skb);
485 out:
486 	return err;
487 }
488 
489 
490 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
491 				 struct sk_buff *skb)
492 {
493 	struct ipv6_pinfo *np = inet6_sk(sk);
494 	bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
495 
496 	if (np->rxopt.bits.rxinfo) {
497 		struct in6_pktinfo src_info;
498 
499 		if (is_ipv6) {
500 			src_info.ipi6_ifindex = IP6CB(skb)->iif;
501 			src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
502 		} else {
503 			src_info.ipi6_ifindex =
504 				PKTINFO_SKB_CB(skb)->ipi_ifindex;
505 			ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
506 					       &src_info.ipi6_addr);
507 		}
508 
509 		if (src_info.ipi6_ifindex >= 0)
510 			put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
511 				 sizeof(src_info), &src_info);
512 	}
513 }
514 
515 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
516 				    struct sk_buff *skb)
517 {
518 	struct ipv6_pinfo *np = inet6_sk(sk);
519 	struct inet6_skb_parm *opt = IP6CB(skb);
520 	unsigned char *nh = skb_network_header(skb);
521 
522 	if (np->rxopt.bits.rxhlim) {
523 		int hlim = ipv6_hdr(skb)->hop_limit;
524 		put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
525 	}
526 
527 	if (np->rxopt.bits.rxtclass) {
528 		int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
529 		put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
530 	}
531 
532 	if (np->rxopt.bits.rxflow) {
533 		__be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
534 		if (flowinfo)
535 			put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
536 	}
537 
538 	/* HbH is allowed only once */
539 	if (np->rxopt.bits.hopopts && opt->hop) {
540 		u8 *ptr = nh + opt->hop;
541 		put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
542 	}
543 
544 	if (opt->lastopt &&
545 	    (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
546 		/*
547 		 * Silly enough, but we need to reparse in order to
548 		 * report extension headers (except for HbH)
549 		 * in order.
550 		 *
551 		 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
552 		 * (and WILL NOT be) defined because
553 		 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
554 		 */
555 		unsigned int off = sizeof(struct ipv6hdr);
556 		u8 nexthdr = ipv6_hdr(skb)->nexthdr;
557 
558 		while (off <= opt->lastopt) {
559 			unsigned int len;
560 			u8 *ptr = nh + off;
561 
562 			switch (nexthdr) {
563 			case IPPROTO_DSTOPTS:
564 				nexthdr = ptr[0];
565 				len = (ptr[1] + 1) << 3;
566 				if (np->rxopt.bits.dstopts)
567 					put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
568 				break;
569 			case IPPROTO_ROUTING:
570 				nexthdr = ptr[0];
571 				len = (ptr[1] + 1) << 3;
572 				if (np->rxopt.bits.srcrt)
573 					put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
574 				break;
575 			case IPPROTO_AH:
576 				nexthdr = ptr[0];
577 				len = (ptr[1] + 2) << 2;
578 				break;
579 			default:
580 				nexthdr = ptr[0];
581 				len = (ptr[1] + 1) << 3;
582 				break;
583 			}
584 
585 			off += len;
586 		}
587 	}
588 
589 	/* socket options in old style */
590 	if (np->rxopt.bits.rxoinfo) {
591 		struct in6_pktinfo src_info;
592 
593 		src_info.ipi6_ifindex = opt->iif;
594 		src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
595 		put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
596 	}
597 	if (np->rxopt.bits.rxohlim) {
598 		int hlim = ipv6_hdr(skb)->hop_limit;
599 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
600 	}
601 	if (np->rxopt.bits.ohopopts && opt->hop) {
602 		u8 *ptr = nh + opt->hop;
603 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
604 	}
605 	if (np->rxopt.bits.odstopts && opt->dst0) {
606 		u8 *ptr = nh + opt->dst0;
607 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
608 	}
609 	if (np->rxopt.bits.osrcrt && opt->srcrt) {
610 		struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
611 		put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
612 	}
613 	if (np->rxopt.bits.odstopts && opt->dst1) {
614 		u8 *ptr = nh + opt->dst1;
615 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
616 	}
617 	if (np->rxopt.bits.rxorigdstaddr) {
618 		struct sockaddr_in6 sin6;
619 		__be16 *ports = (__be16 *) skb_transport_header(skb);
620 
621 		if (skb_transport_offset(skb) + 4 <= skb->len) {
622 			/* All current transport protocols have the port numbers in the
623 			 * first four bytes of the transport header and this function is
624 			 * written with this assumption in mind.
625 			 */
626 
627 			sin6.sin6_family = AF_INET6;
628 			sin6.sin6_addr = ipv6_hdr(skb)->daddr;
629 			sin6.sin6_port = ports[1];
630 			sin6.sin6_flowinfo = 0;
631 			sin6.sin6_scope_id =
632 				ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
633 						    opt->iif);
634 
635 			put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
636 		}
637 	}
638 }
639 
640 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
641 			  struct sk_buff *skb)
642 {
643 	ip6_datagram_recv_common_ctl(sk, msg, skb);
644 	ip6_datagram_recv_specific_ctl(sk, msg, skb);
645 }
646 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
647 
648 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
649 			  struct msghdr *msg, struct flowi6 *fl6,
650 			  struct ipv6_txoptions *opt,
651 			  int *hlimit, int *tclass, int *dontfrag)
652 {
653 	struct in6_pktinfo *src_info;
654 	struct cmsghdr *cmsg;
655 	struct ipv6_rt_hdr *rthdr;
656 	struct ipv6_opt_hdr *hdr;
657 	int len;
658 	int err = 0;
659 
660 	for_each_cmsghdr(cmsg, msg) {
661 		int addr_type;
662 
663 		if (!CMSG_OK(msg, cmsg)) {
664 			err = -EINVAL;
665 			goto exit_f;
666 		}
667 
668 		if (cmsg->cmsg_level != SOL_IPV6)
669 			continue;
670 
671 		switch (cmsg->cmsg_type) {
672 		case IPV6_PKTINFO:
673 		case IPV6_2292PKTINFO:
674 		    {
675 			struct net_device *dev = NULL;
676 
677 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
678 				err = -EINVAL;
679 				goto exit_f;
680 			}
681 
682 			src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
683 
684 			if (src_info->ipi6_ifindex) {
685 				if (fl6->flowi6_oif &&
686 				    src_info->ipi6_ifindex != fl6->flowi6_oif)
687 					return -EINVAL;
688 				fl6->flowi6_oif = src_info->ipi6_ifindex;
689 			}
690 
691 			addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
692 
693 			rcu_read_lock();
694 			if (fl6->flowi6_oif) {
695 				dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
696 				if (!dev) {
697 					rcu_read_unlock();
698 					return -ENODEV;
699 				}
700 			} else if (addr_type & IPV6_ADDR_LINKLOCAL) {
701 				rcu_read_unlock();
702 				return -EINVAL;
703 			}
704 
705 			if (addr_type != IPV6_ADDR_ANY) {
706 				int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
707 				if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
708 				    !ipv6_chk_addr(net, &src_info->ipi6_addr,
709 						   strict ? dev : NULL, 0) &&
710 				    !ipv6_chk_acast_addr_src(net, dev,
711 							     &src_info->ipi6_addr))
712 					err = -EINVAL;
713 				else
714 					fl6->saddr = src_info->ipi6_addr;
715 			}
716 
717 			rcu_read_unlock();
718 
719 			if (err)
720 				goto exit_f;
721 
722 			break;
723 		    }
724 
725 		case IPV6_FLOWINFO:
726 			if (cmsg->cmsg_len < CMSG_LEN(4)) {
727 				err = -EINVAL;
728 				goto exit_f;
729 			}
730 
731 			if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
732 				if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
733 					err = -EINVAL;
734 					goto exit_f;
735 				}
736 			}
737 			fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
738 			break;
739 
740 		case IPV6_2292HOPOPTS:
741 		case IPV6_HOPOPTS:
742 			if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
743 				err = -EINVAL;
744 				goto exit_f;
745 			}
746 
747 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
748 			len = ((hdr->hdrlen + 1) << 3);
749 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
750 				err = -EINVAL;
751 				goto exit_f;
752 			}
753 			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
754 				err = -EPERM;
755 				goto exit_f;
756 			}
757 			opt->opt_nflen += len;
758 			opt->hopopt = hdr;
759 			break;
760 
761 		case IPV6_2292DSTOPTS:
762 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
763 				err = -EINVAL;
764 				goto exit_f;
765 			}
766 
767 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
768 			len = ((hdr->hdrlen + 1) << 3);
769 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
770 				err = -EINVAL;
771 				goto exit_f;
772 			}
773 			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
774 				err = -EPERM;
775 				goto exit_f;
776 			}
777 			if (opt->dst1opt) {
778 				err = -EINVAL;
779 				goto exit_f;
780 			}
781 			opt->opt_flen += len;
782 			opt->dst1opt = hdr;
783 			break;
784 
785 		case IPV6_DSTOPTS:
786 		case IPV6_RTHDRDSTOPTS:
787 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
788 				err = -EINVAL;
789 				goto exit_f;
790 			}
791 
792 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
793 			len = ((hdr->hdrlen + 1) << 3);
794 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
795 				err = -EINVAL;
796 				goto exit_f;
797 			}
798 			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
799 				err = -EPERM;
800 				goto exit_f;
801 			}
802 			if (cmsg->cmsg_type == IPV6_DSTOPTS) {
803 				opt->opt_flen += len;
804 				opt->dst1opt = hdr;
805 			} else {
806 				opt->opt_nflen += len;
807 				opt->dst0opt = hdr;
808 			}
809 			break;
810 
811 		case IPV6_2292RTHDR:
812 		case IPV6_RTHDR:
813 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
814 				err = -EINVAL;
815 				goto exit_f;
816 			}
817 
818 			rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
819 
820 			switch (rthdr->type) {
821 #if IS_ENABLED(CONFIG_IPV6_MIP6)
822 			case IPV6_SRCRT_TYPE_2:
823 				if (rthdr->hdrlen != 2 ||
824 				    rthdr->segments_left != 1) {
825 					err = -EINVAL;
826 					goto exit_f;
827 				}
828 				break;
829 #endif
830 			default:
831 				err = -EINVAL;
832 				goto exit_f;
833 			}
834 
835 			len = ((rthdr->hdrlen + 1) << 3);
836 
837 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
838 				err = -EINVAL;
839 				goto exit_f;
840 			}
841 
842 			/* segments left must also match */
843 			if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
844 				err = -EINVAL;
845 				goto exit_f;
846 			}
847 
848 			opt->opt_nflen += len;
849 			opt->srcrt = rthdr;
850 
851 			if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
852 				int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
853 
854 				opt->opt_nflen += dsthdrlen;
855 				opt->dst0opt = opt->dst1opt;
856 				opt->dst1opt = NULL;
857 				opt->opt_flen -= dsthdrlen;
858 			}
859 
860 			break;
861 
862 		case IPV6_2292HOPLIMIT:
863 		case IPV6_HOPLIMIT:
864 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
865 				err = -EINVAL;
866 				goto exit_f;
867 			}
868 
869 			*hlimit = *(int *)CMSG_DATA(cmsg);
870 			if (*hlimit < -1 || *hlimit > 0xff) {
871 				err = -EINVAL;
872 				goto exit_f;
873 			}
874 
875 			break;
876 
877 		case IPV6_TCLASS:
878 		    {
879 			int tc;
880 
881 			err = -EINVAL;
882 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
883 				goto exit_f;
884 
885 			tc = *(int *)CMSG_DATA(cmsg);
886 			if (tc < -1 || tc > 0xff)
887 				goto exit_f;
888 
889 			err = 0;
890 			*tclass = tc;
891 
892 			break;
893 		    }
894 
895 		case IPV6_DONTFRAG:
896 		    {
897 			int df;
898 
899 			err = -EINVAL;
900 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
901 				goto exit_f;
902 
903 			df = *(int *)CMSG_DATA(cmsg);
904 			if (df < 0 || df > 1)
905 				goto exit_f;
906 
907 			err = 0;
908 			*dontfrag = df;
909 
910 			break;
911 		    }
912 		default:
913 			net_dbg_ratelimited("invalid cmsg type: %d\n",
914 					    cmsg->cmsg_type);
915 			err = -EINVAL;
916 			goto exit_f;
917 		}
918 	}
919 
920 exit_f:
921 	return err;
922 }
923 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
924 
925 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
926 			     __u16 srcp, __u16 destp, int bucket)
927 {
928 	const struct in6_addr *dest, *src;
929 
930 	dest  = &sp->sk_v6_daddr;
931 	src   = &sp->sk_v6_rcv_saddr;
932 	seq_printf(seq,
933 		   "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
934 		   "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
935 		   bucket,
936 		   src->s6_addr32[0], src->s6_addr32[1],
937 		   src->s6_addr32[2], src->s6_addr32[3], srcp,
938 		   dest->s6_addr32[0], dest->s6_addr32[1],
939 		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
940 		   sp->sk_state,
941 		   sk_wmem_alloc_get(sp),
942 		   sk_rmem_alloc_get(sp),
943 		   0, 0L, 0,
944 		   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
945 		   0,
946 		   sock_i_ino(sp),
947 		   atomic_read(&sp->sk_refcnt), sp,
948 		   atomic_read(&sp->sk_drops));
949 }
950