xref: /openbmc/linux/net/ipv6/datagram.c (revision 6774def6)
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;
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 = sock_dequeue_err_skb(sk);
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 out_free_skb:
419 	kfree_skb(skb);
420 out:
421 	return err;
422 }
423 EXPORT_SYMBOL_GPL(ipv6_recv_error);
424 
425 /*
426  *	Handle IPV6_RECVPATHMTU
427  */
428 int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
429 		     int *addr_len)
430 {
431 	struct ipv6_pinfo *np = inet6_sk(sk);
432 	struct sk_buff *skb;
433 	struct ip6_mtuinfo mtu_info;
434 	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
435 	int err;
436 	int copied;
437 
438 	err = -EAGAIN;
439 	skb = xchg(&np->rxpmtu, NULL);
440 	if (skb == NULL)
441 		goto out;
442 
443 	copied = skb->len;
444 	if (copied > len) {
445 		msg->msg_flags |= MSG_TRUNC;
446 		copied = len;
447 	}
448 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
449 	if (err)
450 		goto out_free_skb;
451 
452 	sock_recv_timestamp(msg, sk, skb);
453 
454 	memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
455 
456 	if (sin) {
457 		sin->sin6_family = AF_INET6;
458 		sin->sin6_flowinfo = 0;
459 		sin->sin6_port = 0;
460 		sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
461 		sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
462 		*addr_len = sizeof(*sin);
463 	}
464 
465 	put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
466 
467 	err = copied;
468 
469 out_free_skb:
470 	kfree_skb(skb);
471 out:
472 	return err;
473 }
474 
475 
476 void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
477 				 struct sk_buff *skb)
478 {
479 	struct ipv6_pinfo *np = inet6_sk(sk);
480 	bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
481 
482 	if (np->rxopt.bits.rxinfo) {
483 		struct in6_pktinfo src_info;
484 
485 		if (is_ipv6) {
486 			src_info.ipi6_ifindex = IP6CB(skb)->iif;
487 			src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
488 		} else {
489 			src_info.ipi6_ifindex =
490 				PKTINFO_SKB_CB(skb)->ipi_ifindex;
491 			ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
492 					       &src_info.ipi6_addr);
493 		}
494 		put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
495 	}
496 }
497 
498 void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
499 				    struct sk_buff *skb)
500 {
501 	struct ipv6_pinfo *np = inet6_sk(sk);
502 	struct inet6_skb_parm *opt = IP6CB(skb);
503 	unsigned char *nh = skb_network_header(skb);
504 
505 	if (np->rxopt.bits.rxhlim) {
506 		int hlim = ipv6_hdr(skb)->hop_limit;
507 		put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
508 	}
509 
510 	if (np->rxopt.bits.rxtclass) {
511 		int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
512 		put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
513 	}
514 
515 	if (np->rxopt.bits.rxflow) {
516 		__be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
517 		if (flowinfo)
518 			put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
519 	}
520 
521 	/* HbH is allowed only once */
522 	if (np->rxopt.bits.hopopts && opt->hop) {
523 		u8 *ptr = nh + opt->hop;
524 		put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
525 	}
526 
527 	if (opt->lastopt &&
528 	    (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
529 		/*
530 		 * Silly enough, but we need to reparse in order to
531 		 * report extension headers (except for HbH)
532 		 * in order.
533 		 *
534 		 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
535 		 * (and WILL NOT be) defined because
536 		 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
537 		 */
538 		unsigned int off = sizeof(struct ipv6hdr);
539 		u8 nexthdr = ipv6_hdr(skb)->nexthdr;
540 
541 		while (off <= opt->lastopt) {
542 			unsigned int len;
543 			u8 *ptr = nh + off;
544 
545 			switch (nexthdr) {
546 			case IPPROTO_DSTOPTS:
547 				nexthdr = ptr[0];
548 				len = (ptr[1] + 1) << 3;
549 				if (np->rxopt.bits.dstopts)
550 					put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
551 				break;
552 			case IPPROTO_ROUTING:
553 				nexthdr = ptr[0];
554 				len = (ptr[1] + 1) << 3;
555 				if (np->rxopt.bits.srcrt)
556 					put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
557 				break;
558 			case IPPROTO_AH:
559 				nexthdr = ptr[0];
560 				len = (ptr[1] + 2) << 2;
561 				break;
562 			default:
563 				nexthdr = ptr[0];
564 				len = (ptr[1] + 1) << 3;
565 				break;
566 			}
567 
568 			off += len;
569 		}
570 	}
571 
572 	/* socket options in old style */
573 	if (np->rxopt.bits.rxoinfo) {
574 		struct in6_pktinfo src_info;
575 
576 		src_info.ipi6_ifindex = opt->iif;
577 		src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
578 		put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
579 	}
580 	if (np->rxopt.bits.rxohlim) {
581 		int hlim = ipv6_hdr(skb)->hop_limit;
582 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
583 	}
584 	if (np->rxopt.bits.ohopopts && opt->hop) {
585 		u8 *ptr = nh + opt->hop;
586 		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
587 	}
588 	if (np->rxopt.bits.odstopts && opt->dst0) {
589 		u8 *ptr = nh + opt->dst0;
590 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
591 	}
592 	if (np->rxopt.bits.osrcrt && opt->srcrt) {
593 		struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
594 		put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
595 	}
596 	if (np->rxopt.bits.odstopts && opt->dst1) {
597 		u8 *ptr = nh + opt->dst1;
598 		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
599 	}
600 	if (np->rxopt.bits.rxorigdstaddr) {
601 		struct sockaddr_in6 sin6;
602 		__be16 *ports = (__be16 *) skb_transport_header(skb);
603 
604 		if (skb_transport_offset(skb) + 4 <= skb->len) {
605 			/* All current transport protocols have the port numbers in the
606 			 * first four bytes of the transport header and this function is
607 			 * written with this assumption in mind.
608 			 */
609 
610 			sin6.sin6_family = AF_INET6;
611 			sin6.sin6_addr = ipv6_hdr(skb)->daddr;
612 			sin6.sin6_port = ports[1];
613 			sin6.sin6_flowinfo = 0;
614 			sin6.sin6_scope_id =
615 				ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
616 						    opt->iif);
617 
618 			put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
619 		}
620 	}
621 }
622 
623 void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
624 			  struct sk_buff *skb)
625 {
626 	ip6_datagram_recv_common_ctl(sk, msg, skb);
627 	ip6_datagram_recv_specific_ctl(sk, msg, skb);
628 }
629 EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
630 
631 int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
632 			  struct msghdr *msg, struct flowi6 *fl6,
633 			  struct ipv6_txoptions *opt,
634 			  int *hlimit, int *tclass, int *dontfrag)
635 {
636 	struct in6_pktinfo *src_info;
637 	struct cmsghdr *cmsg;
638 	struct ipv6_rt_hdr *rthdr;
639 	struct ipv6_opt_hdr *hdr;
640 	int len;
641 	int err = 0;
642 
643 	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
644 		int addr_type;
645 
646 		if (!CMSG_OK(msg, cmsg)) {
647 			err = -EINVAL;
648 			goto exit_f;
649 		}
650 
651 		if (cmsg->cmsg_level != SOL_IPV6)
652 			continue;
653 
654 		switch (cmsg->cmsg_type) {
655 		case IPV6_PKTINFO:
656 		case IPV6_2292PKTINFO:
657 		    {
658 			struct net_device *dev = NULL;
659 
660 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
661 				err = -EINVAL;
662 				goto exit_f;
663 			}
664 
665 			src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
666 
667 			if (src_info->ipi6_ifindex) {
668 				if (fl6->flowi6_oif &&
669 				    src_info->ipi6_ifindex != fl6->flowi6_oif)
670 					return -EINVAL;
671 				fl6->flowi6_oif = src_info->ipi6_ifindex;
672 			}
673 
674 			addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
675 
676 			rcu_read_lock();
677 			if (fl6->flowi6_oif) {
678 				dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
679 				if (!dev) {
680 					rcu_read_unlock();
681 					return -ENODEV;
682 				}
683 			} else if (addr_type & IPV6_ADDR_LINKLOCAL) {
684 				rcu_read_unlock();
685 				return -EINVAL;
686 			}
687 
688 			if (addr_type != IPV6_ADDR_ANY) {
689 				int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
690 				if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
691 				    !ipv6_chk_addr(net, &src_info->ipi6_addr,
692 						   strict ? dev : NULL, 0) &&
693 				    !ipv6_chk_acast_addr_src(net, dev,
694 							     &src_info->ipi6_addr))
695 					err = -EINVAL;
696 				else
697 					fl6->saddr = src_info->ipi6_addr;
698 			}
699 
700 			rcu_read_unlock();
701 
702 			if (err)
703 				goto exit_f;
704 
705 			break;
706 		    }
707 
708 		case IPV6_FLOWINFO:
709 			if (cmsg->cmsg_len < CMSG_LEN(4)) {
710 				err = -EINVAL;
711 				goto exit_f;
712 			}
713 
714 			if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
715 				if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
716 					err = -EINVAL;
717 					goto exit_f;
718 				}
719 			}
720 			fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
721 			break;
722 
723 		case IPV6_2292HOPOPTS:
724 		case IPV6_HOPOPTS:
725 			if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
726 				err = -EINVAL;
727 				goto exit_f;
728 			}
729 
730 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
731 			len = ((hdr->hdrlen + 1) << 3);
732 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
733 				err = -EINVAL;
734 				goto exit_f;
735 			}
736 			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
737 				err = -EPERM;
738 				goto exit_f;
739 			}
740 			opt->opt_nflen += len;
741 			opt->hopopt = hdr;
742 			break;
743 
744 		case IPV6_2292DSTOPTS:
745 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
746 				err = -EINVAL;
747 				goto exit_f;
748 			}
749 
750 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
751 			len = ((hdr->hdrlen + 1) << 3);
752 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
753 				err = -EINVAL;
754 				goto exit_f;
755 			}
756 			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
757 				err = -EPERM;
758 				goto exit_f;
759 			}
760 			if (opt->dst1opt) {
761 				err = -EINVAL;
762 				goto exit_f;
763 			}
764 			opt->opt_flen += len;
765 			opt->dst1opt = hdr;
766 			break;
767 
768 		case IPV6_DSTOPTS:
769 		case IPV6_RTHDRDSTOPTS:
770 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
771 				err = -EINVAL;
772 				goto exit_f;
773 			}
774 
775 			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
776 			len = ((hdr->hdrlen + 1) << 3);
777 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
778 				err = -EINVAL;
779 				goto exit_f;
780 			}
781 			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
782 				err = -EPERM;
783 				goto exit_f;
784 			}
785 			if (cmsg->cmsg_type == IPV6_DSTOPTS) {
786 				opt->opt_flen += len;
787 				opt->dst1opt = hdr;
788 			} else {
789 				opt->opt_nflen += len;
790 				opt->dst0opt = hdr;
791 			}
792 			break;
793 
794 		case IPV6_2292RTHDR:
795 		case IPV6_RTHDR:
796 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
797 				err = -EINVAL;
798 				goto exit_f;
799 			}
800 
801 			rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
802 
803 			switch (rthdr->type) {
804 #if IS_ENABLED(CONFIG_IPV6_MIP6)
805 			case IPV6_SRCRT_TYPE_2:
806 				if (rthdr->hdrlen != 2 ||
807 				    rthdr->segments_left != 1) {
808 					err = -EINVAL;
809 					goto exit_f;
810 				}
811 				break;
812 #endif
813 			default:
814 				err = -EINVAL;
815 				goto exit_f;
816 			}
817 
818 			len = ((rthdr->hdrlen + 1) << 3);
819 
820 			if (cmsg->cmsg_len < CMSG_LEN(len)) {
821 				err = -EINVAL;
822 				goto exit_f;
823 			}
824 
825 			/* segments left must also match */
826 			if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
827 				err = -EINVAL;
828 				goto exit_f;
829 			}
830 
831 			opt->opt_nflen += len;
832 			opt->srcrt = rthdr;
833 
834 			if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
835 				int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
836 
837 				opt->opt_nflen += dsthdrlen;
838 				opt->dst0opt = opt->dst1opt;
839 				opt->dst1opt = NULL;
840 				opt->opt_flen -= dsthdrlen;
841 			}
842 
843 			break;
844 
845 		case IPV6_2292HOPLIMIT:
846 		case IPV6_HOPLIMIT:
847 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
848 				err = -EINVAL;
849 				goto exit_f;
850 			}
851 
852 			*hlimit = *(int *)CMSG_DATA(cmsg);
853 			if (*hlimit < -1 || *hlimit > 0xff) {
854 				err = -EINVAL;
855 				goto exit_f;
856 			}
857 
858 			break;
859 
860 		case IPV6_TCLASS:
861 		    {
862 			int tc;
863 
864 			err = -EINVAL;
865 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
866 				goto exit_f;
867 
868 			tc = *(int *)CMSG_DATA(cmsg);
869 			if (tc < -1 || tc > 0xff)
870 				goto exit_f;
871 
872 			err = 0;
873 			*tclass = tc;
874 
875 			break;
876 		    }
877 
878 		case IPV6_DONTFRAG:
879 		    {
880 			int df;
881 
882 			err = -EINVAL;
883 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
884 				goto exit_f;
885 
886 			df = *(int *)CMSG_DATA(cmsg);
887 			if (df < 0 || df > 1)
888 				goto exit_f;
889 
890 			err = 0;
891 			*dontfrag = df;
892 
893 			break;
894 		    }
895 		default:
896 			LIMIT_NETDEBUG(KERN_DEBUG "invalid cmsg type: %d\n",
897 				       cmsg->cmsg_type);
898 			err = -EINVAL;
899 			goto exit_f;
900 		}
901 	}
902 
903 exit_f:
904 	return err;
905 }
906 EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
907 
908 void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
909 			     __u16 srcp, __u16 destp, int bucket)
910 {
911 	const struct in6_addr *dest, *src;
912 
913 	dest  = &sp->sk_v6_daddr;
914 	src   = &sp->sk_v6_rcv_saddr;
915 	seq_printf(seq,
916 		   "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
917 		   "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
918 		   bucket,
919 		   src->s6_addr32[0], src->s6_addr32[1],
920 		   src->s6_addr32[2], src->s6_addr32[3], srcp,
921 		   dest->s6_addr32[0], dest->s6_addr32[1],
922 		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
923 		   sp->sk_state,
924 		   sk_wmem_alloc_get(sp),
925 		   sk_rmem_alloc_get(sp),
926 		   0, 0L, 0,
927 		   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
928 		   0,
929 		   sock_i_ino(sp),
930 		   atomic_read(&sp->sk_refcnt), sp,
931 		   atomic_read(&sp->sk_drops));
932 }
933