xref: /linux/net/ipv6/ipv6_sockglue.c (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	IPv6 BSD socket options interface
4  *	Linux INET6 implementation
5  *
6  *	Authors:
7  *	Pedro Roque		<roque@di.fc.ul.pt>
8  *
9  *	Based on linux/net/ipv4/ip_sockglue.c
10  *
11  *	FIXME: Make the setsockopt code POSIX compliant: That is
12  *
13  *	o	Truncate getsockopt returns
14  *	o	Return an optlen of the truncated length if need be
15  *
16  *	Changes:
17  *	David L Stevens <dlstevens@us.ibm.com>:
18  *		- added multicast source filtering API for MLDv2
19  */
20 
21 #include <linux/module.h>
22 #include <linux/capability.h>
23 #include <linux/errno.h>
24 #include <linux/types.h>
25 #include <linux/socket.h>
26 #include <linux/sockios.h>
27 #include <linux/net.h>
28 #include <linux/in6.h>
29 #include <linux/mroute6.h>
30 #include <linux/netdevice.h>
31 #include <linux/if_arp.h>
32 #include <linux/init.h>
33 #include <linux/sysctl.h>
34 #include <linux/netfilter.h>
35 #include <linux/slab.h>
36 
37 #include <net/sock.h>
38 #include <net/snmp.h>
39 #include <net/ipv6.h>
40 #include <net/ndisc.h>
41 #include <net/protocol.h>
42 #include <net/transp_v6.h>
43 #include <net/ip6_route.h>
44 #include <net/addrconf.h>
45 #include <net/inet_common.h>
46 #include <net/tcp.h>
47 #include <net/udp.h>
48 #include <net/udplite.h>
49 #include <net/xfrm.h>
50 #include <net/compat.h>
51 #include <net/seg6.h>
52 #include <net/psp.h>
53 
54 #include <linux/uaccess.h>
55 
56 struct ip6_ra_chain *ip6_ra_chain;
57 DEFINE_RWLOCK(ip6_ra_lock);
58 
59 DEFINE_STATIC_KEY_FALSE(ip6_min_hopcount);
60 
61 int ip6_ra_control(struct sock *sk, int sel)
62 {
63 	struct ip6_ra_chain *ra, *new_ra, **rap;
64 
65 	/* RA packet may be delivered ONLY to IPPROTO_RAW socket */
66 	if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num != IPPROTO_RAW)
67 		return -ENOPROTOOPT;
68 
69 	new_ra = (sel >= 0) ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
70 	if (sel >= 0 && !new_ra)
71 		return -ENOMEM;
72 
73 	write_lock_bh(&ip6_ra_lock);
74 	for (rap = &ip6_ra_chain; (ra = *rap) != NULL; rap = &ra->next) {
75 		if (ra->sk == sk) {
76 			if (sel >= 0) {
77 				write_unlock_bh(&ip6_ra_lock);
78 				kfree(new_ra);
79 				return -EADDRINUSE;
80 			}
81 
82 			*rap = ra->next;
83 			write_unlock_bh(&ip6_ra_lock);
84 
85 			sock_put(sk);
86 			kfree(ra);
87 			return 0;
88 		}
89 	}
90 	if (!new_ra) {
91 		write_unlock_bh(&ip6_ra_lock);
92 		return -ENOBUFS;
93 	}
94 	new_ra->sk = sk;
95 	new_ra->sel = sel;
96 	new_ra->next = ra;
97 	*rap = new_ra;
98 	sock_hold(sk);
99 	write_unlock_bh(&ip6_ra_lock);
100 	return 0;
101 }
102 
103 struct ipv6_txoptions *ipv6_update_options(struct sock *sk,
104 					   struct ipv6_txoptions *opt)
105 {
106 	if (inet_test_bit(IS_ICSK, sk)) {
107 		if (opt &&
108 		    !((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) &&
109 		    inet_sk(sk)->inet_daddr != LOOPBACK4_IPV6) {
110 			struct inet_connection_sock *icsk = inet_csk(sk);
111 
112 			icsk->icsk_ext_hdr_len =
113 				psp_sk_overhead(sk) +
114 				opt->opt_flen + opt->opt_nflen;
115 			icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
116 		}
117 	}
118 	opt = unrcu_pointer(xchg(&inet6_sk(sk)->opt, RCU_INITIALIZER(opt)));
119 	sk_dst_reset(sk);
120 
121 	return opt;
122 }
123 
124 static int copy_group_source_from_sockptr(struct group_source_req *greqs,
125 		sockptr_t optval, int optlen)
126 {
127 	if (in_compat_syscall()) {
128 		struct compat_group_source_req gr32;
129 
130 		if (optlen < sizeof(gr32))
131 			return -EINVAL;
132 		if (copy_from_sockptr(&gr32, optval, sizeof(gr32)))
133 			return -EFAULT;
134 		greqs->gsr_interface = gr32.gsr_interface;
135 		greqs->gsr_group = gr32.gsr_group;
136 		greqs->gsr_source = gr32.gsr_source;
137 	} else {
138 		if (optlen < sizeof(*greqs))
139 			return -EINVAL;
140 		if (copy_from_sockptr(greqs, optval, sizeof(*greqs)))
141 			return -EFAULT;
142 	}
143 
144 	return 0;
145 }
146 
147 static int do_ipv6_mcast_group_source(struct sock *sk, int optname,
148 		sockptr_t optval, int optlen)
149 {
150 	struct group_source_req greqs;
151 	int omode, add;
152 	int ret;
153 
154 	ret = copy_group_source_from_sockptr(&greqs, optval, optlen);
155 	if (ret)
156 		return ret;
157 
158 	if (greqs.gsr_group.ss_family != AF_INET6 ||
159 	    greqs.gsr_source.ss_family != AF_INET6)
160 		return -EADDRNOTAVAIL;
161 
162 	if (optname == MCAST_BLOCK_SOURCE) {
163 		omode = MCAST_EXCLUDE;
164 		add = 1;
165 	} else if (optname == MCAST_UNBLOCK_SOURCE) {
166 		omode = MCAST_EXCLUDE;
167 		add = 0;
168 	} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
169 		struct sockaddr_in6 *psin6;
170 		int retv;
171 
172 		psin6 = (struct sockaddr_in6 *)&greqs.gsr_group;
173 		retv = ipv6_sock_mc_join_ssm(sk, greqs.gsr_interface,
174 					     &psin6->sin6_addr,
175 					     MCAST_INCLUDE);
176 		/* prior join w/ different source is ok */
177 		if (retv && retv != -EADDRINUSE)
178 			return retv;
179 		omode = MCAST_INCLUDE;
180 		add = 1;
181 	} else /* MCAST_LEAVE_SOURCE_GROUP */ {
182 		omode = MCAST_INCLUDE;
183 		add = 0;
184 	}
185 	return ip6_mc_source(add, omode, sk, &greqs);
186 }
187 
188 static int ipv6_set_mcast_msfilter(struct sock *sk, sockptr_t optval,
189 		int optlen)
190 {
191 	struct group_filter *gsf;
192 	int ret;
193 
194 	if (optlen < GROUP_FILTER_SIZE(0))
195 		return -EINVAL;
196 	if (optlen > READ_ONCE(sock_net(sk)->core.sysctl_optmem_max))
197 		return -ENOBUFS;
198 
199 	gsf = memdup_sockptr(optval, optlen);
200 	if (IS_ERR(gsf))
201 		return PTR_ERR(gsf);
202 
203 	/* numsrc >= (4G-140)/128 overflow in 32 bits */
204 	ret = -ENOBUFS;
205 	if (gsf->gf_numsrc >= 0x1ffffffU ||
206 	    gsf->gf_numsrc > sysctl_mld_max_msf)
207 		goto out_free_gsf;
208 
209 	ret = -EINVAL;
210 	if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen)
211 		goto out_free_gsf;
212 
213 	ret = ip6_mc_msfilter(sk, gsf, gsf->gf_slist_flex);
214 out_free_gsf:
215 	kfree(gsf);
216 	return ret;
217 }
218 
219 static int compat_ipv6_set_mcast_msfilter(struct sock *sk, sockptr_t optval,
220 		int optlen)
221 {
222 	const int size0 = offsetof(struct compat_group_filter, gf_slist_flex);
223 	struct compat_group_filter *gf32;
224 	void *p;
225 	int ret;
226 	int n;
227 
228 	if (optlen < size0)
229 		return -EINVAL;
230 	if (optlen > READ_ONCE(sock_net(sk)->core.sysctl_optmem_max) - 4)
231 		return -ENOBUFS;
232 
233 	p = kmalloc(optlen + 4, GFP_KERNEL);
234 	if (!p)
235 		return -ENOMEM;
236 
237 	gf32 = p + 4; /* we want ->gf_group and ->gf_slist_flex aligned */
238 	ret = -EFAULT;
239 	if (copy_from_sockptr(gf32, optval, optlen))
240 		goto out_free_p;
241 
242 	/* numsrc >= (4G-140)/128 overflow in 32 bits */
243 	ret = -ENOBUFS;
244 	n = gf32->gf_numsrc;
245 	if (n >= 0x1ffffffU || n > sysctl_mld_max_msf)
246 		goto out_free_p;
247 
248 	ret = -EINVAL;
249 	if (offsetof(struct compat_group_filter, gf_slist_flex[n]) > optlen)
250 		goto out_free_p;
251 
252 	ret = ip6_mc_msfilter(sk, &(struct group_filter){
253 			.gf_interface = gf32->gf_interface,
254 			.gf_group = gf32->gf_group,
255 			.gf_fmode = gf32->gf_fmode,
256 			.gf_numsrc = gf32->gf_numsrc}, gf32->gf_slist_flex);
257 
258 out_free_p:
259 	kfree(p);
260 	return ret;
261 }
262 
263 static int ipv6_mcast_join_leave(struct sock *sk, int optname,
264 		sockptr_t optval, int optlen)
265 {
266 	struct sockaddr_in6 *psin6;
267 	struct group_req greq;
268 
269 	if (optlen < sizeof(greq))
270 		return -EINVAL;
271 	if (copy_from_sockptr(&greq, optval, sizeof(greq)))
272 		return -EFAULT;
273 
274 	if (greq.gr_group.ss_family != AF_INET6)
275 		return -EADDRNOTAVAIL;
276 	psin6 = (struct sockaddr_in6 *)&greq.gr_group;
277 	if (optname == MCAST_JOIN_GROUP)
278 		return ipv6_sock_mc_join(sk, greq.gr_interface,
279 					 &psin6->sin6_addr);
280 	return ipv6_sock_mc_drop(sk, greq.gr_interface, &psin6->sin6_addr);
281 }
282 
283 static int compat_ipv6_mcast_join_leave(struct sock *sk, int optname,
284 		sockptr_t optval, int optlen)
285 {
286 	struct compat_group_req gr32;
287 	struct sockaddr_in6 *psin6;
288 
289 	if (optlen < sizeof(gr32))
290 		return -EINVAL;
291 	if (copy_from_sockptr(&gr32, optval, sizeof(gr32)))
292 		return -EFAULT;
293 
294 	if (gr32.gr_group.ss_family != AF_INET6)
295 		return -EADDRNOTAVAIL;
296 	psin6 = (struct sockaddr_in6 *)&gr32.gr_group;
297 	if (optname == MCAST_JOIN_GROUP)
298 		return ipv6_sock_mc_join(sk, gr32.gr_interface,
299 					&psin6->sin6_addr);
300 	return ipv6_sock_mc_drop(sk, gr32.gr_interface, &psin6->sin6_addr);
301 }
302 
303 static int ipv6_set_opt_hdr(struct sock *sk, int optname, sockptr_t optval,
304 		int optlen)
305 {
306 	struct ipv6_pinfo *np = inet6_sk(sk);
307 	struct ipv6_opt_hdr *new = NULL;
308 	struct net *net = sock_net(sk);
309 	struct ipv6_txoptions *opt;
310 	int err;
311 
312 	/* hop-by-hop / destination options are privileged option */
313 	if (optname != IPV6_RTHDR && !sockopt_ns_capable(net->user_ns, CAP_NET_RAW))
314 		return -EPERM;
315 
316 	/* remove any sticky options header with a zero option
317 	 * length, per RFC3542.
318 	 */
319 	if (optlen > 0) {
320 		if (sockptr_is_null(optval))
321 			return -EINVAL;
322 		if (optlen < sizeof(struct ipv6_opt_hdr) ||
323 		    optlen & 0x7 ||
324 		    optlen > 8 * 255)
325 			return -EINVAL;
326 
327 		new = memdup_sockptr(optval, optlen);
328 		if (IS_ERR(new))
329 			return PTR_ERR(new);
330 		if (unlikely(ipv6_optlen(new) > optlen)) {
331 			kfree(new);
332 			return -EINVAL;
333 		}
334 	}
335 
336 	opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
337 	opt = ipv6_renew_options(sk, opt, optname, new);
338 	kfree(new);
339 	if (IS_ERR(opt))
340 		return PTR_ERR(opt);
341 
342 	/* routing header option needs extra check */
343 	err = -EINVAL;
344 	if (optname == IPV6_RTHDR && opt && opt->srcrt) {
345 		struct ipv6_rt_hdr *rthdr = opt->srcrt;
346 		switch (rthdr->type) {
347 #if IS_ENABLED(CONFIG_IPV6_MIP6)
348 		case IPV6_SRCRT_TYPE_2:
349 			if (rthdr->hdrlen != 2 || rthdr->segments_left != 1)
350 				goto sticky_done;
351 			break;
352 #endif
353 		case IPV6_SRCRT_TYPE_4:
354 		{
355 			struct ipv6_sr_hdr *srh =
356 				(struct ipv6_sr_hdr *)opt->srcrt;
357 
358 			if (!seg6_validate_srh(srh, optlen, false))
359 				goto sticky_done;
360 			break;
361 		}
362 		default:
363 			goto sticky_done;
364 		}
365 	}
366 
367 	err = 0;
368 	opt = ipv6_update_options(sk, opt);
369 sticky_done:
370 	if (opt) {
371 		atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
372 		txopt_put(opt);
373 	}
374 	return err;
375 }
376 
377 int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
378 		       sockptr_t optval, unsigned int optlen)
379 {
380 	struct ipv6_pinfo *np = inet6_sk(sk);
381 	struct net *net = sock_net(sk);
382 	int retv = -ENOPROTOOPT;
383 	int val, valbool;
384 
385 	if (sockptr_is_null(optval))
386 		val = 0;
387 	else {
388 		if (optlen >= sizeof(int)) {
389 			if (copy_from_sockptr(&val, optval, sizeof(val)))
390 				return -EFAULT;
391 		} else
392 			val = 0;
393 	}
394 
395 	valbool = (val != 0);
396 
397 	if (ip6_mroute_opt(optname))
398 		return ip6_mroute_setsockopt(sk, optname, optval, optlen);
399 
400 	/* Handle options that can be set without locking the socket. */
401 	switch (optname) {
402 	case IPV6_UNICAST_HOPS:
403 		if (optlen < sizeof(int))
404 			return -EINVAL;
405 		if (val > 255 || val < -1)
406 			return -EINVAL;
407 		WRITE_ONCE(np->hop_limit, val);
408 		return 0;
409 	case IPV6_MULTICAST_LOOP:
410 		if (optlen < sizeof(int))
411 			return -EINVAL;
412 		if (val != valbool)
413 			return -EINVAL;
414 		inet6_assign_bit(MC6_LOOP, sk, valbool);
415 		return 0;
416 	case IPV6_MULTICAST_HOPS:
417 		if (sk->sk_type == SOCK_STREAM)
418 			return retv;
419 		if (optlen < sizeof(int))
420 			return -EINVAL;
421 		if (val > 255 || val < -1)
422 			return -EINVAL;
423 		WRITE_ONCE(np->mcast_hops,
424 			   val == -1 ? IPV6_DEFAULT_MCASTHOPS : val);
425 		return 0;
426 	case IPV6_MTU:
427 		if (optlen < sizeof(int))
428 			return -EINVAL;
429 		if (val && val < IPV6_MIN_MTU)
430 			return -EINVAL;
431 		WRITE_ONCE(np->frag_size, val);
432 		return 0;
433 	case IPV6_MINHOPCOUNT:
434 		if (optlen < sizeof(int))
435 			return -EINVAL;
436 		if (val < 0 || val > 255)
437 			return -EINVAL;
438 
439 		if (val)
440 			static_branch_enable(&ip6_min_hopcount);
441 
442 		/* tcp_v6_err() and tcp_v6_rcv() might read min_hopcount
443 		 * while we are changing it.
444 		 */
445 		WRITE_ONCE(np->min_hopcount, val);
446 		return 0;
447 	case IPV6_RECVERR_RFC4884:
448 		if (optlen < sizeof(int))
449 			return -EINVAL;
450 		if (val < 0 || val > 1)
451 			return -EINVAL;
452 		inet6_assign_bit(RECVERR6_RFC4884, sk, valbool);
453 		return 0;
454 	case IPV6_MULTICAST_ALL:
455 		if (optlen < sizeof(int))
456 			return -EINVAL;
457 		inet6_assign_bit(MC6_ALL, sk, valbool);
458 		return 0;
459 	case IPV6_AUTOFLOWLABEL:
460 		inet6_assign_bit(AUTOFLOWLABEL, sk, valbool);
461 		inet6_set_bit(AUTOFLOWLABEL_SET, sk);
462 		return 0;
463 	case IPV6_DONTFRAG:
464 		inet6_assign_bit(DONTFRAG, sk, valbool);
465 		return 0;
466 	case IPV6_RECVERR:
467 		if (optlen < sizeof(int))
468 			return -EINVAL;
469 		inet6_assign_bit(RECVERR6, sk, valbool);
470 		if (!val)
471 			skb_errqueue_purge(&sk->sk_error_queue);
472 		return 0;
473 	case IPV6_ROUTER_ALERT_ISOLATE:
474 		if (optlen < sizeof(int))
475 			return -EINVAL;
476 		inet6_assign_bit(RTALERT_ISOLATE, sk, valbool);
477 		return 0;
478 	case IPV6_MTU_DISCOVER:
479 		if (optlen < sizeof(int))
480 			return -EINVAL;
481 		if (val < IPV6_PMTUDISC_DONT || val > IPV6_PMTUDISC_OMIT)
482 			return -EINVAL;
483 		WRITE_ONCE(np->pmtudisc, val);
484 		return 0;
485 	case IPV6_FLOWINFO_SEND:
486 		if (optlen < sizeof(int))
487 			return -EINVAL;
488 		inet6_assign_bit(SNDFLOW, sk, valbool);
489 		return 0;
490 	case IPV6_ADDR_PREFERENCES:
491 		if (optlen < sizeof(int))
492 			return -EINVAL;
493 		return ip6_sock_set_addr_preferences(sk, val);
494 	case IPV6_MULTICAST_IF:
495 		if (sk->sk_type == SOCK_STREAM)
496 			return -ENOPROTOOPT;
497 		if (optlen < sizeof(int))
498 			return -EINVAL;
499 		if (val) {
500 			struct net_device *dev;
501 			int bound_dev_if, midx;
502 
503 			rcu_read_lock();
504 
505 			dev = dev_get_by_index_rcu(net, val);
506 			if (!dev) {
507 				rcu_read_unlock();
508 				return -ENODEV;
509 			}
510 			midx = l3mdev_master_ifindex_rcu(dev);
511 
512 			rcu_read_unlock();
513 
514 			bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
515 			if (bound_dev_if &&
516 			    bound_dev_if != val &&
517 			    (!midx || midx != bound_dev_if))
518 				return -EINVAL;
519 		}
520 		WRITE_ONCE(np->mcast_oif, val);
521 		return 0;
522 	case IPV6_UNICAST_IF:
523 	{
524 		struct net_device *dev;
525 		int ifindex;
526 
527 		if (optlen != sizeof(int))
528 			return -EINVAL;
529 
530 		ifindex = (__force int)ntohl((__force __be32)val);
531 		if (!ifindex) {
532 			WRITE_ONCE(np->ucast_oif, 0);
533 			return 0;
534 		}
535 
536 		dev = dev_get_by_index(net, ifindex);
537 		if (!dev)
538 			return -EADDRNOTAVAIL;
539 		dev_put(dev);
540 
541 		if (READ_ONCE(sk->sk_bound_dev_if))
542 			return -EINVAL;
543 
544 		WRITE_ONCE(np->ucast_oif, ifindex);
545 		return 0;
546 	}
547 	}
548 
549 	sockopt_lock_sock(sk);
550 
551 	/* Another thread has converted the socket into IPv4 with
552 	 * IPV6_ADDRFORM concurrently.
553 	 */
554 	if (unlikely(sk->sk_family != AF_INET6))
555 		goto unlock;
556 
557 	switch (optname) {
558 
559 	case IPV6_ADDRFORM:
560 		if (optlen < sizeof(int))
561 			goto e_inval;
562 		if (val == PF_INET) {
563 			if (sk->sk_type == SOCK_RAW)
564 				break;
565 
566 			if (sk->sk_protocol == IPPROTO_UDP ||
567 			    sk->sk_protocol == IPPROTO_UDPLITE) {
568 				struct udp_sock *up = udp_sk(sk);
569 				if (up->pending == AF_INET6) {
570 					retv = -EBUSY;
571 					break;
572 				}
573 			} else if (sk->sk_protocol == IPPROTO_TCP) {
574 				if (sk->sk_prot != &tcpv6_prot) {
575 					retv = -EBUSY;
576 					break;
577 				}
578 			} else {
579 				break;
580 			}
581 
582 			if (sk->sk_state != TCP_ESTABLISHED) {
583 				retv = -ENOTCONN;
584 				break;
585 			}
586 
587 			if (ipv6_only_sock(sk) ||
588 			    !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) {
589 				retv = -EADDRNOTAVAIL;
590 				break;
591 			}
592 
593 			__ipv6_sock_mc_close(sk);
594 			__ipv6_sock_ac_close(sk);
595 
596 			if (sk->sk_protocol == IPPROTO_TCP) {
597 				struct inet_connection_sock *icsk = inet_csk(sk);
598 
599 				sock_prot_inuse_add(net, sk->sk_prot, -1);
600 				sock_prot_inuse_add(net, &tcp_prot, 1);
601 
602 				/* Paired with READ_ONCE(sk->sk_prot) in inet6_stream_ops */
603 				WRITE_ONCE(sk->sk_prot, &tcp_prot);
604 				/* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
605 				WRITE_ONCE(icsk->icsk_af_ops, &ipv4_specific);
606 				WRITE_ONCE(sk->sk_socket->ops, &inet_stream_ops);
607 				WRITE_ONCE(sk->sk_family, PF_INET);
608 				tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
609 			} else {
610 				struct proto *prot = &udp_prot;
611 
612 				if (sk->sk_protocol == IPPROTO_UDPLITE)
613 					prot = &udplite_prot;
614 
615 				sock_prot_inuse_add(net, sk->sk_prot, -1);
616 				sock_prot_inuse_add(net, prot, 1);
617 
618 				/* Paired with READ_ONCE(sk->sk_prot) in inet6_dgram_ops */
619 				WRITE_ONCE(sk->sk_prot, prot);
620 				WRITE_ONCE(sk->sk_socket->ops, &inet_dgram_ops);
621 				WRITE_ONCE(sk->sk_family, PF_INET);
622 			}
623 
624 			/* Disable all options not to allocate memory anymore,
625 			 * but there is still a race.  See the lockless path
626 			 * in udpv6_sendmsg() and ipv6_local_rxpmtu().
627 			 */
628 			np->rxopt.all = 0;
629 
630 			inet6_cleanup_sock(sk);
631 
632 			module_put(THIS_MODULE);
633 			retv = 0;
634 			break;
635 		}
636 		goto e_inval;
637 
638 	case IPV6_V6ONLY:
639 		if (optlen < sizeof(int) ||
640 		    inet_sk(sk)->inet_num)
641 			goto e_inval;
642 		sk->sk_ipv6only = valbool;
643 		retv = 0;
644 		break;
645 
646 	case IPV6_RECVPKTINFO:
647 		if (optlen < sizeof(int))
648 			goto e_inval;
649 		np->rxopt.bits.rxinfo = valbool;
650 		retv = 0;
651 		break;
652 
653 	case IPV6_2292PKTINFO:
654 		if (optlen < sizeof(int))
655 			goto e_inval;
656 		np->rxopt.bits.rxoinfo = valbool;
657 		retv = 0;
658 		break;
659 
660 	case IPV6_RECVHOPLIMIT:
661 		if (optlen < sizeof(int))
662 			goto e_inval;
663 		np->rxopt.bits.rxhlim = valbool;
664 		retv = 0;
665 		break;
666 
667 	case IPV6_2292HOPLIMIT:
668 		if (optlen < sizeof(int))
669 			goto e_inval;
670 		np->rxopt.bits.rxohlim = valbool;
671 		retv = 0;
672 		break;
673 
674 	case IPV6_RECVRTHDR:
675 		if (optlen < sizeof(int))
676 			goto e_inval;
677 		np->rxopt.bits.srcrt = valbool;
678 		retv = 0;
679 		break;
680 
681 	case IPV6_2292RTHDR:
682 		if (optlen < sizeof(int))
683 			goto e_inval;
684 		np->rxopt.bits.osrcrt = valbool;
685 		retv = 0;
686 		break;
687 
688 	case IPV6_RECVHOPOPTS:
689 		if (optlen < sizeof(int))
690 			goto e_inval;
691 		np->rxopt.bits.hopopts = valbool;
692 		retv = 0;
693 		break;
694 
695 	case IPV6_2292HOPOPTS:
696 		if (optlen < sizeof(int))
697 			goto e_inval;
698 		np->rxopt.bits.ohopopts = valbool;
699 		retv = 0;
700 		break;
701 
702 	case IPV6_RECVDSTOPTS:
703 		if (optlen < sizeof(int))
704 			goto e_inval;
705 		np->rxopt.bits.dstopts = valbool;
706 		retv = 0;
707 		break;
708 
709 	case IPV6_2292DSTOPTS:
710 		if (optlen < sizeof(int))
711 			goto e_inval;
712 		np->rxopt.bits.odstopts = valbool;
713 		retv = 0;
714 		break;
715 
716 	case IPV6_TCLASS:
717 		if (optlen < sizeof(int))
718 			goto e_inval;
719 		if (val < -1 || val > 0xff)
720 			goto e_inval;
721 		/* RFC 3542, 6.5: default traffic class of 0x0 */
722 		if (val == -1)
723 			val = 0;
724 		if (sk->sk_type == SOCK_STREAM) {
725 			val &= ~INET_ECN_MASK;
726 			val |= np->tclass & INET_ECN_MASK;
727 		}
728 		if (np->tclass != val) {
729 			np->tclass = val;
730 			sk_dst_reset(sk);
731 		}
732 		retv = 0;
733 		break;
734 
735 	case IPV6_RECVTCLASS:
736 		if (optlen < sizeof(int))
737 			goto e_inval;
738 		np->rxopt.bits.rxtclass = valbool;
739 		retv = 0;
740 		break;
741 
742 	case IPV6_FLOWINFO:
743 		if (optlen < sizeof(int))
744 			goto e_inval;
745 		np->rxopt.bits.rxflow = valbool;
746 		retv = 0;
747 		break;
748 
749 	case IPV6_RECVPATHMTU:
750 		if (optlen < sizeof(int))
751 			goto e_inval;
752 		np->rxopt.bits.rxpmtu = valbool;
753 		retv = 0;
754 		break;
755 
756 	case IPV6_TRANSPARENT:
757 		if (valbool && !sockopt_ns_capable(net->user_ns, CAP_NET_RAW) &&
758 		    !sockopt_ns_capable(net->user_ns, CAP_NET_ADMIN)) {
759 			retv = -EPERM;
760 			break;
761 		}
762 		if (optlen < sizeof(int))
763 			goto e_inval;
764 		/* we don't have a separate transparent bit for IPV6 we use the one in the IPv4 socket */
765 		inet_assign_bit(TRANSPARENT, sk, valbool);
766 		retv = 0;
767 		break;
768 
769 	case IPV6_FREEBIND:
770 		if (optlen < sizeof(int))
771 			goto e_inval;
772 		/* we also don't have a separate freebind bit for IPV6 */
773 		inet_assign_bit(FREEBIND, sk, valbool);
774 		retv = 0;
775 		break;
776 
777 	case IPV6_RECVORIGDSTADDR:
778 		if (optlen < sizeof(int))
779 			goto e_inval;
780 		np->rxopt.bits.rxorigdstaddr = valbool;
781 		retv = 0;
782 		break;
783 
784 	case IPV6_HOPOPTS:
785 	case IPV6_RTHDRDSTOPTS:
786 	case IPV6_RTHDR:
787 	case IPV6_DSTOPTS:
788 		retv = ipv6_set_opt_hdr(sk, optname, optval, optlen);
789 		break;
790 
791 	case IPV6_PKTINFO:
792 	{
793 		struct in6_pktinfo pkt;
794 
795 		if (optlen == 0)
796 			goto e_inval;
797 		else if (optlen < sizeof(struct in6_pktinfo) ||
798 			 sockptr_is_null(optval))
799 			goto e_inval;
800 
801 		if (copy_from_sockptr(&pkt, optval, sizeof(pkt))) {
802 			retv = -EFAULT;
803 			break;
804 		}
805 		if (!sk_dev_equal_l3scope(sk, pkt.ipi6_ifindex))
806 			goto e_inval;
807 
808 		np->sticky_pktinfo.ipi6_ifindex = pkt.ipi6_ifindex;
809 		np->sticky_pktinfo.ipi6_addr = pkt.ipi6_addr;
810 		retv = 0;
811 		break;
812 	}
813 
814 	case IPV6_2292PKTOPTIONS:
815 	{
816 		struct ipv6_txoptions *opt = NULL;
817 		struct msghdr msg;
818 		struct flowi6 fl6;
819 		struct ipcm6_cookie ipc6;
820 
821 		memset(&fl6, 0, sizeof(fl6));
822 		fl6.flowi6_oif = sk->sk_bound_dev_if;
823 		fl6.flowi6_mark = sk->sk_mark;
824 
825 		if (optlen == 0)
826 			goto update;
827 
828 		/* 1K is probably excessive
829 		 * 1K is surely not enough, 2K per standard header is 16K.
830 		 */
831 		retv = -EINVAL;
832 		if (optlen > 64*1024)
833 			break;
834 
835 		opt = sock_kmalloc(sk, sizeof(*opt) + optlen, GFP_KERNEL);
836 		retv = -ENOBUFS;
837 		if (!opt)
838 			break;
839 
840 		memset(opt, 0, sizeof(*opt));
841 		refcount_set(&opt->refcnt, 1);
842 		opt->tot_len = sizeof(*opt) + optlen;
843 		retv = -EFAULT;
844 		if (copy_from_sockptr(opt + 1, optval, optlen))
845 			goto done;
846 
847 		msg.msg_controllen = optlen;
848 		msg.msg_control_is_user = false;
849 		msg.msg_control = (void *)(opt+1);
850 		ipc6.opt = opt;
851 
852 		retv = ip6_datagram_send_ctl(net, sk, &msg, &fl6, &ipc6);
853 		if (retv)
854 			goto done;
855 update:
856 		retv = 0;
857 		opt = ipv6_update_options(sk, opt);
858 done:
859 		if (opt) {
860 			atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
861 			txopt_put(opt);
862 		}
863 		break;
864 	}
865 
866 	case IPV6_ADD_MEMBERSHIP:
867 	case IPV6_DROP_MEMBERSHIP:
868 	{
869 		struct ipv6_mreq mreq;
870 
871 		if (optlen < sizeof(struct ipv6_mreq))
872 			goto e_inval;
873 
874 		retv = -EPROTO;
875 		if (inet_test_bit(IS_ICSK, sk))
876 			break;
877 
878 		retv = -EFAULT;
879 		if (copy_from_sockptr(&mreq, optval, sizeof(struct ipv6_mreq)))
880 			break;
881 
882 		if (optname == IPV6_ADD_MEMBERSHIP)
883 			retv = ipv6_sock_mc_join(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr);
884 		else
885 			retv = ipv6_sock_mc_drop(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr);
886 		break;
887 	}
888 	case IPV6_JOIN_ANYCAST:
889 	case IPV6_LEAVE_ANYCAST:
890 	{
891 		struct ipv6_mreq mreq;
892 
893 		if (optlen < sizeof(struct ipv6_mreq))
894 			goto e_inval;
895 
896 		retv = -EFAULT;
897 		if (copy_from_sockptr(&mreq, optval, sizeof(struct ipv6_mreq)))
898 			break;
899 
900 		if (optname == IPV6_JOIN_ANYCAST)
901 			retv = ipv6_sock_ac_join(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_acaddr);
902 		else
903 			retv = ipv6_sock_ac_drop(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_acaddr);
904 		break;
905 	}
906 	case MCAST_JOIN_GROUP:
907 	case MCAST_LEAVE_GROUP:
908 		if (in_compat_syscall())
909 			retv = compat_ipv6_mcast_join_leave(sk, optname, optval,
910 							    optlen);
911 		else
912 			retv = ipv6_mcast_join_leave(sk, optname, optval,
913 						     optlen);
914 		break;
915 	case MCAST_JOIN_SOURCE_GROUP:
916 	case MCAST_LEAVE_SOURCE_GROUP:
917 	case MCAST_BLOCK_SOURCE:
918 	case MCAST_UNBLOCK_SOURCE:
919 		retv = do_ipv6_mcast_group_source(sk, optname, optval, optlen);
920 		break;
921 	case MCAST_MSFILTER:
922 		if (in_compat_syscall())
923 			retv = compat_ipv6_set_mcast_msfilter(sk, optval,
924 							      optlen);
925 		else
926 			retv = ipv6_set_mcast_msfilter(sk, optval, optlen);
927 		break;
928 	case IPV6_ROUTER_ALERT:
929 		if (optlen < sizeof(int))
930 			goto e_inval;
931 		retv = ip6_ra_control(sk, val);
932 		if (retv == 0)
933 			inet6_assign_bit(RTALERT, sk, valbool);
934 		break;
935 	case IPV6_FLOWLABEL_MGR:
936 		retv = ipv6_flowlabel_opt(sk, optval, optlen);
937 		break;
938 	case IPV6_IPSEC_POLICY:
939 	case IPV6_XFRM_POLICY:
940 		retv = -EPERM;
941 		if (!sockopt_ns_capable(net->user_ns, CAP_NET_ADMIN))
942 			break;
943 		retv = xfrm_user_policy(sk, optname, optval, optlen);
944 		break;
945 
946 	case IPV6_RECVFRAGSIZE:
947 		np->rxopt.bits.recvfragsize = valbool;
948 		retv = 0;
949 		break;
950 	}
951 
952 unlock:
953 	sockopt_release_sock(sk);
954 
955 	return retv;
956 
957 e_inval:
958 	retv = -EINVAL;
959 	goto unlock;
960 }
961 
962 int ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
963 		    unsigned int optlen)
964 {
965 	int err;
966 
967 	if (level == SOL_IP && sk->sk_type != SOCK_RAW)
968 		return ip_setsockopt(sk, level, optname, optval, optlen);
969 
970 	if (level != SOL_IPV6)
971 		return -ENOPROTOOPT;
972 
973 	err = do_ipv6_setsockopt(sk, level, optname, optval, optlen);
974 #ifdef CONFIG_NETFILTER
975 	/* we need to exclude all possible ENOPROTOOPTs except default case */
976 	if (err == -ENOPROTOOPT && optname != IPV6_IPSEC_POLICY &&
977 			optname != IPV6_XFRM_POLICY)
978 		err = nf_setsockopt(sk, PF_INET6, optname, optval, optlen);
979 #endif
980 	return err;
981 }
982 EXPORT_SYMBOL(ipv6_setsockopt);
983 
984 static int ipv6_getsockopt_sticky(struct sock *sk, struct ipv6_txoptions *opt,
985 				  int optname, sockptr_t optval, int len)
986 {
987 	struct ipv6_opt_hdr *hdr;
988 
989 	if (!opt)
990 		return 0;
991 
992 	switch (optname) {
993 	case IPV6_HOPOPTS:
994 		hdr = opt->hopopt;
995 		break;
996 	case IPV6_RTHDRDSTOPTS:
997 		hdr = opt->dst0opt;
998 		break;
999 	case IPV6_RTHDR:
1000 		hdr = (struct ipv6_opt_hdr *)opt->srcrt;
1001 		break;
1002 	case IPV6_DSTOPTS:
1003 		hdr = opt->dst1opt;
1004 		break;
1005 	default:
1006 		return -EINVAL;	/* should not happen */
1007 	}
1008 
1009 	if (!hdr)
1010 		return 0;
1011 
1012 	len = min_t(unsigned int, len, ipv6_optlen(hdr));
1013 	if (copy_to_sockptr(optval, hdr, len))
1014 		return -EFAULT;
1015 	return len;
1016 }
1017 
1018 static int ipv6_get_msfilter(struct sock *sk, sockptr_t optval,
1019 			     sockptr_t optlen, int len)
1020 {
1021 	const int size0 = offsetof(struct group_filter, gf_slist_flex);
1022 	struct group_filter gsf;
1023 	int num;
1024 	int err;
1025 
1026 	if (len < size0)
1027 		return -EINVAL;
1028 	if (copy_from_sockptr(&gsf, optval, size0))
1029 		return -EFAULT;
1030 	if (gsf.gf_group.ss_family != AF_INET6)
1031 		return -EADDRNOTAVAIL;
1032 	num = gsf.gf_numsrc;
1033 	sockopt_lock_sock(sk);
1034 	err = ip6_mc_msfget(sk, &gsf, optval, size0);
1035 	if (!err) {
1036 		if (num > gsf.gf_numsrc)
1037 			num = gsf.gf_numsrc;
1038 		len = GROUP_FILTER_SIZE(num);
1039 		if (copy_to_sockptr(optlen, &len, sizeof(int)) ||
1040 		    copy_to_sockptr(optval, &gsf, size0))
1041 			err = -EFAULT;
1042 	}
1043 	sockopt_release_sock(sk);
1044 	return err;
1045 }
1046 
1047 static int compat_ipv6_get_msfilter(struct sock *sk, sockptr_t optval,
1048 				    sockptr_t optlen, int len)
1049 {
1050 	const int size0 = offsetof(struct compat_group_filter, gf_slist_flex);
1051 	struct compat_group_filter gf32;
1052 	struct group_filter gf;
1053 	int err;
1054 	int num;
1055 
1056 	if (len < size0)
1057 		return -EINVAL;
1058 
1059 	if (copy_from_sockptr(&gf32, optval, size0))
1060 		return -EFAULT;
1061 	gf.gf_interface = gf32.gf_interface;
1062 	gf.gf_fmode = gf32.gf_fmode;
1063 	num = gf.gf_numsrc = gf32.gf_numsrc;
1064 	gf.gf_group = gf32.gf_group;
1065 
1066 	if (gf.gf_group.ss_family != AF_INET6)
1067 		return -EADDRNOTAVAIL;
1068 
1069 	sockopt_lock_sock(sk);
1070 	err = ip6_mc_msfget(sk, &gf, optval, size0);
1071 	sockopt_release_sock(sk);
1072 	if (err)
1073 		return err;
1074 	if (num > gf.gf_numsrc)
1075 		num = gf.gf_numsrc;
1076 	len = GROUP_FILTER_SIZE(num) - (sizeof(gf)-sizeof(gf32));
1077 	if (copy_to_sockptr(optlen, &len, sizeof(int)) ||
1078 	    copy_to_sockptr_offset(optval, offsetof(struct compat_group_filter, gf_fmode),
1079 				   &gf.gf_fmode, sizeof(gf32.gf_fmode)) ||
1080 	    copy_to_sockptr_offset(optval, offsetof(struct compat_group_filter, gf_numsrc),
1081 				   &gf.gf_numsrc, sizeof(gf32.gf_numsrc)))
1082 		return -EFAULT;
1083 	return 0;
1084 }
1085 
1086 int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
1087 		       sockptr_t optval, sockptr_t optlen)
1088 {
1089 	struct ipv6_pinfo *np = inet6_sk(sk);
1090 	int len;
1091 	int val;
1092 
1093 	if (ip6_mroute_opt(optname))
1094 		return ip6_mroute_getsockopt(sk, optname, optval, optlen);
1095 
1096 	if (copy_from_sockptr(&len, optlen, sizeof(int)))
1097 		return -EFAULT;
1098 	switch (optname) {
1099 	case IPV6_ADDRFORM:
1100 		if (sk->sk_protocol != IPPROTO_UDP &&
1101 		    sk->sk_protocol != IPPROTO_UDPLITE &&
1102 		    sk->sk_protocol != IPPROTO_TCP)
1103 			return -ENOPROTOOPT;
1104 		if (sk->sk_state != TCP_ESTABLISHED)
1105 			return -ENOTCONN;
1106 		val = sk->sk_family;
1107 		break;
1108 	case MCAST_MSFILTER:
1109 		if (in_compat_syscall())
1110 			return compat_ipv6_get_msfilter(sk, optval, optlen, len);
1111 		return ipv6_get_msfilter(sk, optval, optlen, len);
1112 	case IPV6_2292PKTOPTIONS:
1113 	{
1114 		struct msghdr msg;
1115 		struct sk_buff *skb;
1116 
1117 		if (sk->sk_type != SOCK_STREAM)
1118 			return -ENOPROTOOPT;
1119 
1120 		if (optval.is_kernel) {
1121 			msg.msg_control_is_user = false;
1122 			msg.msg_control = optval.kernel;
1123 		} else {
1124 			msg.msg_control_is_user = true;
1125 			msg.msg_control_user = optval.user;
1126 		}
1127 		msg.msg_controllen = len;
1128 		msg.msg_flags = 0;
1129 
1130 		sockopt_lock_sock(sk);
1131 		skb = np->pktoptions;
1132 		if (skb)
1133 			ip6_datagram_recv_ctl(sk, &msg, skb);
1134 		sockopt_release_sock(sk);
1135 		if (!skb) {
1136 			if (np->rxopt.bits.rxinfo) {
1137 				int mcast_oif = READ_ONCE(np->mcast_oif);
1138 				struct in6_pktinfo src_info;
1139 
1140 				src_info.ipi6_ifindex = mcast_oif ? :
1141 					np->sticky_pktinfo.ipi6_ifindex;
1142 				src_info.ipi6_addr = mcast_oif ? sk->sk_v6_daddr : np->sticky_pktinfo.ipi6_addr;
1143 				put_cmsg(&msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
1144 			}
1145 			if (np->rxopt.bits.rxhlim) {
1146 				int hlim = READ_ONCE(np->mcast_hops);
1147 
1148 				put_cmsg(&msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
1149 			}
1150 			if (np->rxopt.bits.rxtclass) {
1151 				int tclass = (int)ip6_tclass(np->rcv_flowinfo);
1152 
1153 				put_cmsg(&msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
1154 			}
1155 			if (np->rxopt.bits.rxoinfo) {
1156 				int mcast_oif = READ_ONCE(np->mcast_oif);
1157 				struct in6_pktinfo src_info;
1158 
1159 				src_info.ipi6_ifindex = mcast_oif ? :
1160 					np->sticky_pktinfo.ipi6_ifindex;
1161 				src_info.ipi6_addr = mcast_oif ? sk->sk_v6_daddr :
1162 								 np->sticky_pktinfo.ipi6_addr;
1163 				put_cmsg(&msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
1164 			}
1165 			if (np->rxopt.bits.rxohlim) {
1166 				int hlim = READ_ONCE(np->mcast_hops);
1167 
1168 				put_cmsg(&msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
1169 			}
1170 			if (np->rxopt.bits.rxflow) {
1171 				__be32 flowinfo = np->rcv_flowinfo;
1172 
1173 				put_cmsg(&msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
1174 			}
1175 		}
1176 		len -= msg.msg_controllen;
1177 		return copy_to_sockptr(optlen, &len, sizeof(int));
1178 	}
1179 	case IPV6_MTU:
1180 	{
1181 		struct dst_entry *dst;
1182 
1183 		val = 0;
1184 		rcu_read_lock();
1185 		dst = __sk_dst_get(sk);
1186 		if (dst)
1187 			val = dst_mtu(dst);
1188 		rcu_read_unlock();
1189 		if (!val)
1190 			return -ENOTCONN;
1191 		break;
1192 	}
1193 
1194 	case IPV6_V6ONLY:
1195 		val = sk->sk_ipv6only;
1196 		break;
1197 
1198 	case IPV6_RECVPKTINFO:
1199 		val = np->rxopt.bits.rxinfo;
1200 		break;
1201 
1202 	case IPV6_2292PKTINFO:
1203 		val = np->rxopt.bits.rxoinfo;
1204 		break;
1205 
1206 	case IPV6_RECVHOPLIMIT:
1207 		val = np->rxopt.bits.rxhlim;
1208 		break;
1209 
1210 	case IPV6_2292HOPLIMIT:
1211 		val = np->rxopt.bits.rxohlim;
1212 		break;
1213 
1214 	case IPV6_RECVRTHDR:
1215 		val = np->rxopt.bits.srcrt;
1216 		break;
1217 
1218 	case IPV6_2292RTHDR:
1219 		val = np->rxopt.bits.osrcrt;
1220 		break;
1221 
1222 	case IPV6_HOPOPTS:
1223 	case IPV6_RTHDRDSTOPTS:
1224 	case IPV6_RTHDR:
1225 	case IPV6_DSTOPTS:
1226 	{
1227 		struct ipv6_txoptions *opt;
1228 
1229 		sockopt_lock_sock(sk);
1230 		opt = rcu_dereference_protected(np->opt,
1231 						lockdep_sock_is_held(sk));
1232 		len = ipv6_getsockopt_sticky(sk, opt, optname, optval, len);
1233 		sockopt_release_sock(sk);
1234 		/* check if ipv6_getsockopt_sticky() returns err code */
1235 		if (len < 0)
1236 			return len;
1237 		return copy_to_sockptr(optlen, &len, sizeof(int));
1238 	}
1239 
1240 	case IPV6_RECVHOPOPTS:
1241 		val = np->rxopt.bits.hopopts;
1242 		break;
1243 
1244 	case IPV6_2292HOPOPTS:
1245 		val = np->rxopt.bits.ohopopts;
1246 		break;
1247 
1248 	case IPV6_RECVDSTOPTS:
1249 		val = np->rxopt.bits.dstopts;
1250 		break;
1251 
1252 	case IPV6_2292DSTOPTS:
1253 		val = np->rxopt.bits.odstopts;
1254 		break;
1255 
1256 	case IPV6_TCLASS:
1257 		val = np->tclass;
1258 		break;
1259 
1260 	case IPV6_RECVTCLASS:
1261 		val = np->rxopt.bits.rxtclass;
1262 		break;
1263 
1264 	case IPV6_FLOWINFO:
1265 		val = np->rxopt.bits.rxflow;
1266 		break;
1267 
1268 	case IPV6_RECVPATHMTU:
1269 		val = np->rxopt.bits.rxpmtu;
1270 		break;
1271 
1272 	case IPV6_PATHMTU:
1273 	{
1274 		struct dst_entry *dst;
1275 		struct ip6_mtuinfo mtuinfo;
1276 
1277 		if (len < sizeof(mtuinfo))
1278 			return -EINVAL;
1279 
1280 		len = sizeof(mtuinfo);
1281 		memset(&mtuinfo, 0, sizeof(mtuinfo));
1282 
1283 		rcu_read_lock();
1284 		dst = __sk_dst_get(sk);
1285 		if (dst)
1286 			mtuinfo.ip6m_mtu = dst_mtu(dst);
1287 		rcu_read_unlock();
1288 		if (!mtuinfo.ip6m_mtu)
1289 			return -ENOTCONN;
1290 
1291 		if (copy_to_sockptr(optlen, &len, sizeof(int)))
1292 			return -EFAULT;
1293 		if (copy_to_sockptr(optval, &mtuinfo, len))
1294 			return -EFAULT;
1295 
1296 		return 0;
1297 	}
1298 
1299 	case IPV6_TRANSPARENT:
1300 		val = inet_test_bit(TRANSPARENT, sk);
1301 		break;
1302 
1303 	case IPV6_FREEBIND:
1304 		val = inet_test_bit(FREEBIND, sk);
1305 		break;
1306 
1307 	case IPV6_RECVORIGDSTADDR:
1308 		val = np->rxopt.bits.rxorigdstaddr;
1309 		break;
1310 
1311 	case IPV6_UNICAST_HOPS:
1312 	case IPV6_MULTICAST_HOPS:
1313 	{
1314 		struct dst_entry *dst;
1315 
1316 		if (optname == IPV6_UNICAST_HOPS)
1317 			val = READ_ONCE(np->hop_limit);
1318 		else
1319 			val = READ_ONCE(np->mcast_hops);
1320 
1321 		if (val < 0) {
1322 			rcu_read_lock();
1323 			dst = __sk_dst_get(sk);
1324 			if (dst)
1325 				val = ip6_dst_hoplimit(dst);
1326 			rcu_read_unlock();
1327 		}
1328 
1329 		if (val < 0)
1330 			val = READ_ONCE(sock_net(sk)->ipv6.devconf_all->hop_limit);
1331 		break;
1332 	}
1333 
1334 	case IPV6_MULTICAST_LOOP:
1335 		val = inet6_test_bit(MC6_LOOP, sk);
1336 		break;
1337 
1338 	case IPV6_MULTICAST_IF:
1339 		val = READ_ONCE(np->mcast_oif);
1340 		break;
1341 
1342 	case IPV6_MULTICAST_ALL:
1343 		val = inet6_test_bit(MC6_ALL, sk);
1344 		break;
1345 
1346 	case IPV6_UNICAST_IF:
1347 		val = (__force int)htonl((__u32) READ_ONCE(np->ucast_oif));
1348 		break;
1349 
1350 	case IPV6_MTU_DISCOVER:
1351 		val = READ_ONCE(np->pmtudisc);
1352 		break;
1353 
1354 	case IPV6_RECVERR:
1355 		val = inet6_test_bit(RECVERR6, sk);
1356 		break;
1357 
1358 	case IPV6_FLOWINFO_SEND:
1359 		val = inet6_test_bit(SNDFLOW, sk);
1360 		break;
1361 
1362 	case IPV6_FLOWLABEL_MGR:
1363 	{
1364 		struct in6_flowlabel_req freq;
1365 		int flags;
1366 
1367 		if (len < sizeof(freq))
1368 			return -EINVAL;
1369 
1370 		if (copy_from_sockptr(&freq, optval, sizeof(freq)))
1371 			return -EFAULT;
1372 
1373 		if (freq.flr_action != IPV6_FL_A_GET)
1374 			return -EINVAL;
1375 
1376 		len = sizeof(freq);
1377 		flags = freq.flr_flags;
1378 
1379 		memset(&freq, 0, sizeof(freq));
1380 
1381 		val = ipv6_flowlabel_opt_get(sk, &freq, flags);
1382 		if (val < 0)
1383 			return val;
1384 
1385 		if (copy_to_sockptr(optlen, &len, sizeof(int)))
1386 			return -EFAULT;
1387 		if (copy_to_sockptr(optval, &freq, len))
1388 			return -EFAULT;
1389 
1390 		return 0;
1391 	}
1392 
1393 	case IPV6_ADDR_PREFERENCES:
1394 		{
1395 		u8 srcprefs = READ_ONCE(np->srcprefs);
1396 		val = 0;
1397 
1398 		if (srcprefs & IPV6_PREFER_SRC_TMP)
1399 			val |= IPV6_PREFER_SRC_TMP;
1400 		else if (srcprefs & IPV6_PREFER_SRC_PUBLIC)
1401 			val |= IPV6_PREFER_SRC_PUBLIC;
1402 		else {
1403 			/* XXX: should we return system default? */
1404 			val |= IPV6_PREFER_SRC_PUBTMP_DEFAULT;
1405 		}
1406 
1407 		if (srcprefs & IPV6_PREFER_SRC_COA)
1408 			val |= IPV6_PREFER_SRC_COA;
1409 		else
1410 			val |= IPV6_PREFER_SRC_HOME;
1411 		break;
1412 		}
1413 	case IPV6_MINHOPCOUNT:
1414 		val = READ_ONCE(np->min_hopcount);
1415 		break;
1416 
1417 	case IPV6_DONTFRAG:
1418 		val = inet6_test_bit(DONTFRAG, sk);
1419 		break;
1420 
1421 	case IPV6_AUTOFLOWLABEL:
1422 		val = ip6_autoflowlabel(sock_net(sk), sk);
1423 		break;
1424 
1425 	case IPV6_RECVFRAGSIZE:
1426 		val = np->rxopt.bits.recvfragsize;
1427 		break;
1428 
1429 	case IPV6_ROUTER_ALERT:
1430 		val = inet6_test_bit(RTALERT, sk);
1431 		break;
1432 
1433 	case IPV6_ROUTER_ALERT_ISOLATE:
1434 		val = inet6_test_bit(RTALERT_ISOLATE, sk);
1435 		break;
1436 
1437 	case IPV6_RECVERR_RFC4884:
1438 		val = inet6_test_bit(RECVERR6_RFC4884, sk);
1439 		break;
1440 
1441 	default:
1442 		return -ENOPROTOOPT;
1443 	}
1444 	len = min_t(unsigned int, sizeof(int), len);
1445 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
1446 		return -EFAULT;
1447 	if (copy_to_sockptr(optval, &val, len))
1448 		return -EFAULT;
1449 	return 0;
1450 }
1451 
1452 int ipv6_getsockopt(struct sock *sk, int level, int optname,
1453 		    char __user *optval, int __user *optlen)
1454 {
1455 	int err;
1456 
1457 	if (level == SOL_IP && sk->sk_type != SOCK_RAW)
1458 		return ip_getsockopt(sk, level, optname, optval, optlen);
1459 
1460 	if (level != SOL_IPV6)
1461 		return -ENOPROTOOPT;
1462 
1463 	err = do_ipv6_getsockopt(sk, level, optname,
1464 				 USER_SOCKPTR(optval), USER_SOCKPTR(optlen));
1465 #ifdef CONFIG_NETFILTER
1466 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1467 	if (err == -ENOPROTOOPT && optname != IPV6_2292PKTOPTIONS) {
1468 		int len;
1469 
1470 		if (get_user(len, optlen))
1471 			return -EFAULT;
1472 
1473 		err = nf_getsockopt(sk, PF_INET6, optname, optval, &len);
1474 		if (err >= 0)
1475 			err = put_user(len, optlen);
1476 	}
1477 #endif
1478 	return err;
1479 }
1480 EXPORT_SYMBOL(ipv6_getsockopt);
1481