xref: /linux/net/ipv6/ipv6_sockglue.c (revision 83cd5eb654b320c1972254f243531f3f3cebcccf)
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 
53 #include <linux/uaccess.h>
54 
55 struct ip6_ra_chain *ip6_ra_chain;
56 DEFINE_RWLOCK(ip6_ra_lock);
57 
58 DEFINE_STATIC_KEY_FALSE(ip6_min_hopcount);
59 
60 int ip6_ra_control(struct sock *sk, int sel)
61 {
62 	struct ip6_ra_chain *ra, *new_ra, **rap;
63 
64 	/* RA packet may be delivered ONLY to IPPROTO_RAW socket */
65 	if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num != IPPROTO_RAW)
66 		return -ENOPROTOOPT;
67 
68 	new_ra = (sel >= 0) ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
69 	if (sel >= 0 && !new_ra)
70 		return -ENOMEM;
71 
72 	write_lock_bh(&ip6_ra_lock);
73 	for (rap = &ip6_ra_chain; (ra = *rap) != NULL; rap = &ra->next) {
74 		if (ra->sk == sk) {
75 			if (sel >= 0) {
76 				write_unlock_bh(&ip6_ra_lock);
77 				kfree(new_ra);
78 				return -EADDRINUSE;
79 			}
80 
81 			*rap = ra->next;
82 			write_unlock_bh(&ip6_ra_lock);
83 
84 			sock_put(sk);
85 			kfree(ra);
86 			return 0;
87 		}
88 	}
89 	if (!new_ra) {
90 		write_unlock_bh(&ip6_ra_lock);
91 		return -ENOBUFS;
92 	}
93 	new_ra->sk = sk;
94 	new_ra->sel = sel;
95 	new_ra->next = ra;
96 	*rap = new_ra;
97 	sock_hold(sk);
98 	write_unlock_bh(&ip6_ra_lock);
99 	return 0;
100 }
101 
102 struct ipv6_txoptions *ipv6_update_options(struct sock *sk,
103 					   struct ipv6_txoptions *opt)
104 {
105 	if (inet_test_bit(IS_ICSK, sk)) {
106 		if (opt &&
107 		    !((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) &&
108 		    inet_sk(sk)->inet_daddr != LOOPBACK4_IPV6) {
109 			struct inet_connection_sock *icsk = inet_csk(sk);
110 			icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen;
111 			icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
112 		}
113 	}
114 	opt = xchg((__force struct ipv6_txoptions **)&inet6_sk(sk)->opt,
115 		   opt);
116 	sk_dst_reset(sk);
117 
118 	return opt;
119 }
120 
121 static bool setsockopt_needs_rtnl(int optname)
122 {
123 	switch (optname) {
124 	case IPV6_ADDRFORM:
125 	case IPV6_ADD_MEMBERSHIP:
126 	case IPV6_DROP_MEMBERSHIP:
127 	case IPV6_JOIN_ANYCAST:
128 	case IPV6_LEAVE_ANYCAST:
129 	case MCAST_JOIN_GROUP:
130 	case MCAST_LEAVE_GROUP:
131 	case MCAST_JOIN_SOURCE_GROUP:
132 	case MCAST_LEAVE_SOURCE_GROUP:
133 	case MCAST_BLOCK_SOURCE:
134 	case MCAST_UNBLOCK_SOURCE:
135 	case MCAST_MSFILTER:
136 		return true;
137 	}
138 	return false;
139 }
140 
141 static int copy_group_source_from_sockptr(struct group_source_req *greqs,
142 		sockptr_t optval, int optlen)
143 {
144 	if (in_compat_syscall()) {
145 		struct compat_group_source_req gr32;
146 
147 		if (optlen < sizeof(gr32))
148 			return -EINVAL;
149 		if (copy_from_sockptr(&gr32, optval, sizeof(gr32)))
150 			return -EFAULT;
151 		greqs->gsr_interface = gr32.gsr_interface;
152 		greqs->gsr_group = gr32.gsr_group;
153 		greqs->gsr_source = gr32.gsr_source;
154 	} else {
155 		if (optlen < sizeof(*greqs))
156 			return -EINVAL;
157 		if (copy_from_sockptr(greqs, optval, sizeof(*greqs)))
158 			return -EFAULT;
159 	}
160 
161 	return 0;
162 }
163 
164 static int do_ipv6_mcast_group_source(struct sock *sk, int optname,
165 		sockptr_t optval, int optlen)
166 {
167 	struct group_source_req greqs;
168 	int omode, add;
169 	int ret;
170 
171 	ret = copy_group_source_from_sockptr(&greqs, optval, optlen);
172 	if (ret)
173 		return ret;
174 
175 	if (greqs.gsr_group.ss_family != AF_INET6 ||
176 	    greqs.gsr_source.ss_family != AF_INET6)
177 		return -EADDRNOTAVAIL;
178 
179 	if (optname == MCAST_BLOCK_SOURCE) {
180 		omode = MCAST_EXCLUDE;
181 		add = 1;
182 	} else if (optname == MCAST_UNBLOCK_SOURCE) {
183 		omode = MCAST_EXCLUDE;
184 		add = 0;
185 	} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
186 		struct sockaddr_in6 *psin6;
187 		int retv;
188 
189 		psin6 = (struct sockaddr_in6 *)&greqs.gsr_group;
190 		retv = ipv6_sock_mc_join_ssm(sk, greqs.gsr_interface,
191 					     &psin6->sin6_addr,
192 					     MCAST_INCLUDE);
193 		/* prior join w/ different source is ok */
194 		if (retv && retv != -EADDRINUSE)
195 			return retv;
196 		omode = MCAST_INCLUDE;
197 		add = 1;
198 	} else /* MCAST_LEAVE_SOURCE_GROUP */ {
199 		omode = MCAST_INCLUDE;
200 		add = 0;
201 	}
202 	return ip6_mc_source(add, omode, sk, &greqs);
203 }
204 
205 static int ipv6_set_mcast_msfilter(struct sock *sk, sockptr_t optval,
206 		int optlen)
207 {
208 	struct group_filter *gsf;
209 	int ret;
210 
211 	if (optlen < GROUP_FILTER_SIZE(0))
212 		return -EINVAL;
213 	if (optlen > READ_ONCE(sysctl_optmem_max))
214 		return -ENOBUFS;
215 
216 	gsf = memdup_sockptr(optval, optlen);
217 	if (IS_ERR(gsf))
218 		return PTR_ERR(gsf);
219 
220 	/* numsrc >= (4G-140)/128 overflow in 32 bits */
221 	ret = -ENOBUFS;
222 	if (gsf->gf_numsrc >= 0x1ffffffU ||
223 	    gsf->gf_numsrc > sysctl_mld_max_msf)
224 		goto out_free_gsf;
225 
226 	ret = -EINVAL;
227 	if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen)
228 		goto out_free_gsf;
229 
230 	ret = ip6_mc_msfilter(sk, gsf, gsf->gf_slist_flex);
231 out_free_gsf:
232 	kfree(gsf);
233 	return ret;
234 }
235 
236 static int compat_ipv6_set_mcast_msfilter(struct sock *sk, sockptr_t optval,
237 		int optlen)
238 {
239 	const int size0 = offsetof(struct compat_group_filter, gf_slist_flex);
240 	struct compat_group_filter *gf32;
241 	void *p;
242 	int ret;
243 	int n;
244 
245 	if (optlen < size0)
246 		return -EINVAL;
247 	if (optlen > READ_ONCE(sysctl_optmem_max) - 4)
248 		return -ENOBUFS;
249 
250 	p = kmalloc(optlen + 4, GFP_KERNEL);
251 	if (!p)
252 		return -ENOMEM;
253 
254 	gf32 = p + 4; /* we want ->gf_group and ->gf_slist_flex aligned */
255 	ret = -EFAULT;
256 	if (copy_from_sockptr(gf32, optval, optlen))
257 		goto out_free_p;
258 
259 	/* numsrc >= (4G-140)/128 overflow in 32 bits */
260 	ret = -ENOBUFS;
261 	n = gf32->gf_numsrc;
262 	if (n >= 0x1ffffffU || n > sysctl_mld_max_msf)
263 		goto out_free_p;
264 
265 	ret = -EINVAL;
266 	if (offsetof(struct compat_group_filter, gf_slist_flex[n]) > optlen)
267 		goto out_free_p;
268 
269 	ret = ip6_mc_msfilter(sk, &(struct group_filter){
270 			.gf_interface = gf32->gf_interface,
271 			.gf_group = gf32->gf_group,
272 			.gf_fmode = gf32->gf_fmode,
273 			.gf_numsrc = gf32->gf_numsrc}, gf32->gf_slist_flex);
274 
275 out_free_p:
276 	kfree(p);
277 	return ret;
278 }
279 
280 static int ipv6_mcast_join_leave(struct sock *sk, int optname,
281 		sockptr_t optval, int optlen)
282 {
283 	struct sockaddr_in6 *psin6;
284 	struct group_req greq;
285 
286 	if (optlen < sizeof(greq))
287 		return -EINVAL;
288 	if (copy_from_sockptr(&greq, optval, sizeof(greq)))
289 		return -EFAULT;
290 
291 	if (greq.gr_group.ss_family != AF_INET6)
292 		return -EADDRNOTAVAIL;
293 	psin6 = (struct sockaddr_in6 *)&greq.gr_group;
294 	if (optname == MCAST_JOIN_GROUP)
295 		return ipv6_sock_mc_join(sk, greq.gr_interface,
296 					 &psin6->sin6_addr);
297 	return ipv6_sock_mc_drop(sk, greq.gr_interface, &psin6->sin6_addr);
298 }
299 
300 static int compat_ipv6_mcast_join_leave(struct sock *sk, int optname,
301 		sockptr_t optval, int optlen)
302 {
303 	struct compat_group_req gr32;
304 	struct sockaddr_in6 *psin6;
305 
306 	if (optlen < sizeof(gr32))
307 		return -EINVAL;
308 	if (copy_from_sockptr(&gr32, optval, sizeof(gr32)))
309 		return -EFAULT;
310 
311 	if (gr32.gr_group.ss_family != AF_INET6)
312 		return -EADDRNOTAVAIL;
313 	psin6 = (struct sockaddr_in6 *)&gr32.gr_group;
314 	if (optname == MCAST_JOIN_GROUP)
315 		return ipv6_sock_mc_join(sk, gr32.gr_interface,
316 					&psin6->sin6_addr);
317 	return ipv6_sock_mc_drop(sk, gr32.gr_interface, &psin6->sin6_addr);
318 }
319 
320 static int ipv6_set_opt_hdr(struct sock *sk, int optname, sockptr_t optval,
321 		int optlen)
322 {
323 	struct ipv6_pinfo *np = inet6_sk(sk);
324 	struct ipv6_opt_hdr *new = NULL;
325 	struct net *net = sock_net(sk);
326 	struct ipv6_txoptions *opt;
327 	int err;
328 
329 	/* hop-by-hop / destination options are privileged option */
330 	if (optname != IPV6_RTHDR && !sockopt_ns_capable(net->user_ns, CAP_NET_RAW))
331 		return -EPERM;
332 
333 	/* remove any sticky options header with a zero option
334 	 * length, per RFC3542.
335 	 */
336 	if (optlen > 0) {
337 		if (sockptr_is_null(optval))
338 			return -EINVAL;
339 		if (optlen < sizeof(struct ipv6_opt_hdr) ||
340 		    optlen & 0x7 ||
341 		    optlen > 8 * 255)
342 			return -EINVAL;
343 
344 		new = memdup_sockptr(optval, optlen);
345 		if (IS_ERR(new))
346 			return PTR_ERR(new);
347 		if (unlikely(ipv6_optlen(new) > optlen)) {
348 			kfree(new);
349 			return -EINVAL;
350 		}
351 	}
352 
353 	opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
354 	opt = ipv6_renew_options(sk, opt, optname, new);
355 	kfree(new);
356 	if (IS_ERR(opt))
357 		return PTR_ERR(opt);
358 
359 	/* routing header option needs extra check */
360 	err = -EINVAL;
361 	if (optname == IPV6_RTHDR && opt && opt->srcrt) {
362 		struct ipv6_rt_hdr *rthdr = opt->srcrt;
363 		switch (rthdr->type) {
364 #if IS_ENABLED(CONFIG_IPV6_MIP6)
365 		case IPV6_SRCRT_TYPE_2:
366 			if (rthdr->hdrlen != 2 || rthdr->segments_left != 1)
367 				goto sticky_done;
368 			break;
369 #endif
370 		case IPV6_SRCRT_TYPE_4:
371 		{
372 			struct ipv6_sr_hdr *srh =
373 				(struct ipv6_sr_hdr *)opt->srcrt;
374 
375 			if (!seg6_validate_srh(srh, optlen, false))
376 				goto sticky_done;
377 			break;
378 		}
379 		default:
380 			goto sticky_done;
381 		}
382 	}
383 
384 	err = 0;
385 	opt = ipv6_update_options(sk, opt);
386 sticky_done:
387 	if (opt) {
388 		atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
389 		txopt_put(opt);
390 	}
391 	return err;
392 }
393 
394 int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
395 		       sockptr_t optval, unsigned int optlen)
396 {
397 	struct ipv6_pinfo *np = inet6_sk(sk);
398 	struct net *net = sock_net(sk);
399 	int val, valbool;
400 	int retv = -ENOPROTOOPT;
401 	bool needs_rtnl = setsockopt_needs_rtnl(optname);
402 
403 	if (sockptr_is_null(optval))
404 		val = 0;
405 	else {
406 		if (optlen >= sizeof(int)) {
407 			if (copy_from_sockptr(&val, optval, sizeof(val)))
408 				return -EFAULT;
409 		} else
410 			val = 0;
411 	}
412 
413 	valbool = (val != 0);
414 
415 	if (ip6_mroute_opt(optname))
416 		return ip6_mroute_setsockopt(sk, optname, optval, optlen);
417 
418 	/* Handle options that can be set without locking the socket. */
419 	switch (optname) {
420 	case IPV6_UNICAST_HOPS:
421 		if (optlen < sizeof(int))
422 			return -EINVAL;
423 		if (val > 255 || val < -1)
424 			return -EINVAL;
425 		WRITE_ONCE(np->hop_limit, val);
426 		return 0;
427 	case IPV6_MULTICAST_LOOP:
428 		if (optlen < sizeof(int))
429 			return -EINVAL;
430 		if (val != valbool)
431 			return -EINVAL;
432 		inet6_assign_bit(MC6_LOOP, sk, valbool);
433 		return 0;
434 	case IPV6_MULTICAST_HOPS:
435 		if (sk->sk_type == SOCK_STREAM)
436 			return retv;
437 		if (optlen < sizeof(int))
438 			return -EINVAL;
439 		if (val > 255 || val < -1)
440 			return -EINVAL;
441 		WRITE_ONCE(np->mcast_hops,
442 			   val == -1 ? IPV6_DEFAULT_MCASTHOPS : val);
443 		return 0;
444 	case IPV6_MTU:
445 		if (optlen < sizeof(int))
446 			return -EINVAL;
447 		if (val && val < IPV6_MIN_MTU)
448 			return -EINVAL;
449 		WRITE_ONCE(np->frag_size, val);
450 		return 0;
451 	case IPV6_MINHOPCOUNT:
452 		if (optlen < sizeof(int))
453 			return -EINVAL;
454 		if (val < 0 || val > 255)
455 			return -EINVAL;
456 
457 		if (val)
458 			static_branch_enable(&ip6_min_hopcount);
459 
460 		/* tcp_v6_err() and tcp_v6_rcv() might read min_hopcount
461 		 * while we are changing it.
462 		 */
463 		WRITE_ONCE(np->min_hopcount, val);
464 		return 0;
465 	case IPV6_RECVERR_RFC4884:
466 		if (optlen < sizeof(int))
467 			return -EINVAL;
468 		if (val < 0 || val > 1)
469 			return -EINVAL;
470 		inet6_assign_bit(RECVERR6_RFC4884, sk, valbool);
471 		return 0;
472 	case IPV6_MULTICAST_ALL:
473 		if (optlen < sizeof(int))
474 			return -EINVAL;
475 		inet6_assign_bit(MC6_ALL, sk, valbool);
476 		return 0;
477 	case IPV6_AUTOFLOWLABEL:
478 		inet6_assign_bit(AUTOFLOWLABEL, sk, valbool);
479 		inet6_set_bit(AUTOFLOWLABEL_SET, sk);
480 		return 0;
481 	case IPV6_DONTFRAG:
482 		inet6_assign_bit(DONTFRAG, sk, valbool);
483 		return 0;
484 	case IPV6_RECVERR:
485 		if (optlen < sizeof(int))
486 			return -EINVAL;
487 		inet6_assign_bit(RECVERR6, sk, valbool);
488 		if (!val)
489 			skb_errqueue_purge(&sk->sk_error_queue);
490 		return 0;
491 	case IPV6_ROUTER_ALERT_ISOLATE:
492 		if (optlen < sizeof(int))
493 			return -EINVAL;
494 		inet6_assign_bit(RTALERT_ISOLATE, sk, valbool);
495 		return 0;
496 	}
497 	if (needs_rtnl)
498 		rtnl_lock();
499 	sockopt_lock_sock(sk);
500 
501 	/* Another thread has converted the socket into IPv4 with
502 	 * IPV6_ADDRFORM concurrently.
503 	 */
504 	if (unlikely(sk->sk_family != AF_INET6))
505 		goto unlock;
506 
507 	switch (optname) {
508 
509 	case IPV6_ADDRFORM:
510 		if (optlen < sizeof(int))
511 			goto e_inval;
512 		if (val == PF_INET) {
513 			if (sk->sk_type == SOCK_RAW)
514 				break;
515 
516 			if (sk->sk_protocol == IPPROTO_UDP ||
517 			    sk->sk_protocol == IPPROTO_UDPLITE) {
518 				struct udp_sock *up = udp_sk(sk);
519 				if (up->pending == AF_INET6) {
520 					retv = -EBUSY;
521 					break;
522 				}
523 			} else if (sk->sk_protocol == IPPROTO_TCP) {
524 				if (sk->sk_prot != &tcpv6_prot) {
525 					retv = -EBUSY;
526 					break;
527 				}
528 			} else {
529 				break;
530 			}
531 
532 			if (sk->sk_state != TCP_ESTABLISHED) {
533 				retv = -ENOTCONN;
534 				break;
535 			}
536 
537 			if (ipv6_only_sock(sk) ||
538 			    !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) {
539 				retv = -EADDRNOTAVAIL;
540 				break;
541 			}
542 
543 			__ipv6_sock_mc_close(sk);
544 			__ipv6_sock_ac_close(sk);
545 
546 			if (sk->sk_protocol == IPPROTO_TCP) {
547 				struct inet_connection_sock *icsk = inet_csk(sk);
548 
549 				sock_prot_inuse_add(net, sk->sk_prot, -1);
550 				sock_prot_inuse_add(net, &tcp_prot, 1);
551 
552 				/* Paired with READ_ONCE(sk->sk_prot) in inet6_stream_ops */
553 				WRITE_ONCE(sk->sk_prot, &tcp_prot);
554 				/* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
555 				WRITE_ONCE(icsk->icsk_af_ops, &ipv4_specific);
556 				WRITE_ONCE(sk->sk_socket->ops, &inet_stream_ops);
557 				WRITE_ONCE(sk->sk_family, PF_INET);
558 				tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
559 			} else {
560 				struct proto *prot = &udp_prot;
561 
562 				if (sk->sk_protocol == IPPROTO_UDPLITE)
563 					prot = &udplite_prot;
564 
565 				sock_prot_inuse_add(net, sk->sk_prot, -1);
566 				sock_prot_inuse_add(net, prot, 1);
567 
568 				/* Paired with READ_ONCE(sk->sk_prot) in inet6_dgram_ops */
569 				WRITE_ONCE(sk->sk_prot, prot);
570 				WRITE_ONCE(sk->sk_socket->ops, &inet_dgram_ops);
571 				WRITE_ONCE(sk->sk_family, PF_INET);
572 			}
573 
574 			/* Disable all options not to allocate memory anymore,
575 			 * but there is still a race.  See the lockless path
576 			 * in udpv6_sendmsg() and ipv6_local_rxpmtu().
577 			 */
578 			np->rxopt.all = 0;
579 
580 			inet6_cleanup_sock(sk);
581 
582 			module_put(THIS_MODULE);
583 			retv = 0;
584 			break;
585 		}
586 		goto e_inval;
587 
588 	case IPV6_V6ONLY:
589 		if (optlen < sizeof(int) ||
590 		    inet_sk(sk)->inet_num)
591 			goto e_inval;
592 		sk->sk_ipv6only = valbool;
593 		retv = 0;
594 		break;
595 
596 	case IPV6_RECVPKTINFO:
597 		if (optlen < sizeof(int))
598 			goto e_inval;
599 		np->rxopt.bits.rxinfo = valbool;
600 		retv = 0;
601 		break;
602 
603 	case IPV6_2292PKTINFO:
604 		if (optlen < sizeof(int))
605 			goto e_inval;
606 		np->rxopt.bits.rxoinfo = valbool;
607 		retv = 0;
608 		break;
609 
610 	case IPV6_RECVHOPLIMIT:
611 		if (optlen < sizeof(int))
612 			goto e_inval;
613 		np->rxopt.bits.rxhlim = valbool;
614 		retv = 0;
615 		break;
616 
617 	case IPV6_2292HOPLIMIT:
618 		if (optlen < sizeof(int))
619 			goto e_inval;
620 		np->rxopt.bits.rxohlim = valbool;
621 		retv = 0;
622 		break;
623 
624 	case IPV6_RECVRTHDR:
625 		if (optlen < sizeof(int))
626 			goto e_inval;
627 		np->rxopt.bits.srcrt = valbool;
628 		retv = 0;
629 		break;
630 
631 	case IPV6_2292RTHDR:
632 		if (optlen < sizeof(int))
633 			goto e_inval;
634 		np->rxopt.bits.osrcrt = valbool;
635 		retv = 0;
636 		break;
637 
638 	case IPV6_RECVHOPOPTS:
639 		if (optlen < sizeof(int))
640 			goto e_inval;
641 		np->rxopt.bits.hopopts = valbool;
642 		retv = 0;
643 		break;
644 
645 	case IPV6_2292HOPOPTS:
646 		if (optlen < sizeof(int))
647 			goto e_inval;
648 		np->rxopt.bits.ohopopts = valbool;
649 		retv = 0;
650 		break;
651 
652 	case IPV6_RECVDSTOPTS:
653 		if (optlen < sizeof(int))
654 			goto e_inval;
655 		np->rxopt.bits.dstopts = valbool;
656 		retv = 0;
657 		break;
658 
659 	case IPV6_2292DSTOPTS:
660 		if (optlen < sizeof(int))
661 			goto e_inval;
662 		np->rxopt.bits.odstopts = valbool;
663 		retv = 0;
664 		break;
665 
666 	case IPV6_TCLASS:
667 		if (optlen < sizeof(int))
668 			goto e_inval;
669 		if (val < -1 || val > 0xff)
670 			goto e_inval;
671 		/* RFC 3542, 6.5: default traffic class of 0x0 */
672 		if (val == -1)
673 			val = 0;
674 		if (sk->sk_type == SOCK_STREAM) {
675 			val &= ~INET_ECN_MASK;
676 			val |= np->tclass & INET_ECN_MASK;
677 		}
678 		if (np->tclass != val) {
679 			np->tclass = val;
680 			sk_dst_reset(sk);
681 		}
682 		retv = 0;
683 		break;
684 
685 	case IPV6_RECVTCLASS:
686 		if (optlen < sizeof(int))
687 			goto e_inval;
688 		np->rxopt.bits.rxtclass = valbool;
689 		retv = 0;
690 		break;
691 
692 	case IPV6_FLOWINFO:
693 		if (optlen < sizeof(int))
694 			goto e_inval;
695 		np->rxopt.bits.rxflow = valbool;
696 		retv = 0;
697 		break;
698 
699 	case IPV6_RECVPATHMTU:
700 		if (optlen < sizeof(int))
701 			goto e_inval;
702 		np->rxopt.bits.rxpmtu = valbool;
703 		retv = 0;
704 		break;
705 
706 	case IPV6_TRANSPARENT:
707 		if (valbool && !sockopt_ns_capable(net->user_ns, CAP_NET_RAW) &&
708 		    !sockopt_ns_capable(net->user_ns, CAP_NET_ADMIN)) {
709 			retv = -EPERM;
710 			break;
711 		}
712 		if (optlen < sizeof(int))
713 			goto e_inval;
714 		/* we don't have a separate transparent bit for IPV6 we use the one in the IPv4 socket */
715 		inet_assign_bit(TRANSPARENT, sk, valbool);
716 		retv = 0;
717 		break;
718 
719 	case IPV6_FREEBIND:
720 		if (optlen < sizeof(int))
721 			goto e_inval;
722 		/* we also don't have a separate freebind bit for IPV6 */
723 		inet_assign_bit(FREEBIND, sk, valbool);
724 		retv = 0;
725 		break;
726 
727 	case IPV6_RECVORIGDSTADDR:
728 		if (optlen < sizeof(int))
729 			goto e_inval;
730 		np->rxopt.bits.rxorigdstaddr = valbool;
731 		retv = 0;
732 		break;
733 
734 	case IPV6_HOPOPTS:
735 	case IPV6_RTHDRDSTOPTS:
736 	case IPV6_RTHDR:
737 	case IPV6_DSTOPTS:
738 		retv = ipv6_set_opt_hdr(sk, optname, optval, optlen);
739 		break;
740 
741 	case IPV6_PKTINFO:
742 	{
743 		struct in6_pktinfo pkt;
744 
745 		if (optlen == 0)
746 			goto e_inval;
747 		else if (optlen < sizeof(struct in6_pktinfo) ||
748 			 sockptr_is_null(optval))
749 			goto e_inval;
750 
751 		if (copy_from_sockptr(&pkt, optval, sizeof(pkt))) {
752 			retv = -EFAULT;
753 			break;
754 		}
755 		if (!sk_dev_equal_l3scope(sk, pkt.ipi6_ifindex))
756 			goto e_inval;
757 
758 		np->sticky_pktinfo.ipi6_ifindex = pkt.ipi6_ifindex;
759 		np->sticky_pktinfo.ipi6_addr = pkt.ipi6_addr;
760 		retv = 0;
761 		break;
762 	}
763 
764 	case IPV6_2292PKTOPTIONS:
765 	{
766 		struct ipv6_txoptions *opt = NULL;
767 		struct msghdr msg;
768 		struct flowi6 fl6;
769 		struct ipcm6_cookie ipc6;
770 
771 		memset(&fl6, 0, sizeof(fl6));
772 		fl6.flowi6_oif = sk->sk_bound_dev_if;
773 		fl6.flowi6_mark = sk->sk_mark;
774 
775 		if (optlen == 0)
776 			goto update;
777 
778 		/* 1K is probably excessive
779 		 * 1K is surely not enough, 2K per standard header is 16K.
780 		 */
781 		retv = -EINVAL;
782 		if (optlen > 64*1024)
783 			break;
784 
785 		opt = sock_kmalloc(sk, sizeof(*opt) + optlen, GFP_KERNEL);
786 		retv = -ENOBUFS;
787 		if (!opt)
788 			break;
789 
790 		memset(opt, 0, sizeof(*opt));
791 		refcount_set(&opt->refcnt, 1);
792 		opt->tot_len = sizeof(*opt) + optlen;
793 		retv = -EFAULT;
794 		if (copy_from_sockptr(opt + 1, optval, optlen))
795 			goto done;
796 
797 		msg.msg_controllen = optlen;
798 		msg.msg_control_is_user = false;
799 		msg.msg_control = (void *)(opt+1);
800 		ipc6.opt = opt;
801 
802 		retv = ip6_datagram_send_ctl(net, sk, &msg, &fl6, &ipc6);
803 		if (retv)
804 			goto done;
805 update:
806 		retv = 0;
807 		opt = ipv6_update_options(sk, opt);
808 done:
809 		if (opt) {
810 			atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
811 			txopt_put(opt);
812 		}
813 		break;
814 	}
815 
816 
817 	case IPV6_UNICAST_IF:
818 	{
819 		struct net_device *dev = NULL;
820 		int ifindex;
821 
822 		if (optlen != sizeof(int))
823 			goto e_inval;
824 
825 		ifindex = (__force int)ntohl((__force __be32)val);
826 		if (ifindex == 0) {
827 			np->ucast_oif = 0;
828 			retv = 0;
829 			break;
830 		}
831 
832 		dev = dev_get_by_index(net, ifindex);
833 		retv = -EADDRNOTAVAIL;
834 		if (!dev)
835 			break;
836 		dev_put(dev);
837 
838 		retv = -EINVAL;
839 		if (sk->sk_bound_dev_if)
840 			break;
841 
842 		np->ucast_oif = ifindex;
843 		retv = 0;
844 		break;
845 	}
846 
847 	case IPV6_MULTICAST_IF:
848 		if (sk->sk_type == SOCK_STREAM)
849 			break;
850 		if (optlen < sizeof(int))
851 			goto e_inval;
852 
853 		if (val) {
854 			struct net_device *dev;
855 			int midx;
856 
857 			rcu_read_lock();
858 
859 			dev = dev_get_by_index_rcu(net, val);
860 			if (!dev) {
861 				rcu_read_unlock();
862 				retv = -ENODEV;
863 				break;
864 			}
865 			midx = l3mdev_master_ifindex_rcu(dev);
866 
867 			rcu_read_unlock();
868 
869 			if (sk->sk_bound_dev_if &&
870 			    sk->sk_bound_dev_if != val &&
871 			    (!midx || midx != sk->sk_bound_dev_if))
872 				goto e_inval;
873 		}
874 		np->mcast_oif = val;
875 		retv = 0;
876 		break;
877 	case IPV6_ADD_MEMBERSHIP:
878 	case IPV6_DROP_MEMBERSHIP:
879 	{
880 		struct ipv6_mreq mreq;
881 
882 		if (optlen < sizeof(struct ipv6_mreq))
883 			goto e_inval;
884 
885 		retv = -EPROTO;
886 		if (inet_test_bit(IS_ICSK, sk))
887 			break;
888 
889 		retv = -EFAULT;
890 		if (copy_from_sockptr(&mreq, optval, sizeof(struct ipv6_mreq)))
891 			break;
892 
893 		if (optname == IPV6_ADD_MEMBERSHIP)
894 			retv = ipv6_sock_mc_join(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr);
895 		else
896 			retv = ipv6_sock_mc_drop(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr);
897 		break;
898 	}
899 	case IPV6_JOIN_ANYCAST:
900 	case IPV6_LEAVE_ANYCAST:
901 	{
902 		struct ipv6_mreq mreq;
903 
904 		if (optlen < sizeof(struct ipv6_mreq))
905 			goto e_inval;
906 
907 		retv = -EFAULT;
908 		if (copy_from_sockptr(&mreq, optval, sizeof(struct ipv6_mreq)))
909 			break;
910 
911 		if (optname == IPV6_JOIN_ANYCAST)
912 			retv = ipv6_sock_ac_join(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_acaddr);
913 		else
914 			retv = ipv6_sock_ac_drop(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_acaddr);
915 		break;
916 	}
917 	case MCAST_JOIN_GROUP:
918 	case MCAST_LEAVE_GROUP:
919 		if (in_compat_syscall())
920 			retv = compat_ipv6_mcast_join_leave(sk, optname, optval,
921 							    optlen);
922 		else
923 			retv = ipv6_mcast_join_leave(sk, optname, optval,
924 						     optlen);
925 		break;
926 	case MCAST_JOIN_SOURCE_GROUP:
927 	case MCAST_LEAVE_SOURCE_GROUP:
928 	case MCAST_BLOCK_SOURCE:
929 	case MCAST_UNBLOCK_SOURCE:
930 		retv = do_ipv6_mcast_group_source(sk, optname, optval, optlen);
931 		break;
932 	case MCAST_MSFILTER:
933 		if (in_compat_syscall())
934 			retv = compat_ipv6_set_mcast_msfilter(sk, optval,
935 							      optlen);
936 		else
937 			retv = ipv6_set_mcast_msfilter(sk, optval, optlen);
938 		break;
939 	case IPV6_ROUTER_ALERT:
940 		if (optlen < sizeof(int))
941 			goto e_inval;
942 		retv = ip6_ra_control(sk, val);
943 		break;
944 	case IPV6_MTU_DISCOVER:
945 		if (optlen < sizeof(int))
946 			goto e_inval;
947 		if (val < IPV6_PMTUDISC_DONT || val > IPV6_PMTUDISC_OMIT)
948 			goto e_inval;
949 		np->pmtudisc = val;
950 		retv = 0;
951 		break;
952 	case IPV6_FLOWINFO_SEND:
953 		if (optlen < sizeof(int))
954 			goto e_inval;
955 		np->sndflow = valbool;
956 		retv = 0;
957 		break;
958 	case IPV6_FLOWLABEL_MGR:
959 		retv = ipv6_flowlabel_opt(sk, optval, optlen);
960 		break;
961 	case IPV6_IPSEC_POLICY:
962 	case IPV6_XFRM_POLICY:
963 		retv = -EPERM;
964 		if (!sockopt_ns_capable(net->user_ns, CAP_NET_ADMIN))
965 			break;
966 		retv = xfrm_user_policy(sk, optname, optval, optlen);
967 		break;
968 
969 	case IPV6_ADDR_PREFERENCES:
970 		if (optlen < sizeof(int))
971 			goto e_inval;
972 		retv = __ip6_sock_set_addr_preferences(sk, val);
973 		break;
974 	case IPV6_RECVFRAGSIZE:
975 		np->rxopt.bits.recvfragsize = valbool;
976 		retv = 0;
977 		break;
978 	}
979 
980 unlock:
981 	sockopt_release_sock(sk);
982 	if (needs_rtnl)
983 		rtnl_unlock();
984 
985 	return retv;
986 
987 e_inval:
988 	retv = -EINVAL;
989 	goto unlock;
990 }
991 
992 int ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
993 		    unsigned int optlen)
994 {
995 	int err;
996 
997 	if (level == SOL_IP && sk->sk_type != SOCK_RAW)
998 		return udp_prot.setsockopt(sk, level, optname, optval, optlen);
999 
1000 	if (level != SOL_IPV6)
1001 		return -ENOPROTOOPT;
1002 
1003 	err = do_ipv6_setsockopt(sk, level, optname, optval, optlen);
1004 #ifdef CONFIG_NETFILTER
1005 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1006 	if (err == -ENOPROTOOPT && optname != IPV6_IPSEC_POLICY &&
1007 			optname != IPV6_XFRM_POLICY)
1008 		err = nf_setsockopt(sk, PF_INET6, optname, optval, optlen);
1009 #endif
1010 	return err;
1011 }
1012 EXPORT_SYMBOL(ipv6_setsockopt);
1013 
1014 static int ipv6_getsockopt_sticky(struct sock *sk, struct ipv6_txoptions *opt,
1015 				  int optname, sockptr_t optval, int len)
1016 {
1017 	struct ipv6_opt_hdr *hdr;
1018 
1019 	if (!opt)
1020 		return 0;
1021 
1022 	switch (optname) {
1023 	case IPV6_HOPOPTS:
1024 		hdr = opt->hopopt;
1025 		break;
1026 	case IPV6_RTHDRDSTOPTS:
1027 		hdr = opt->dst0opt;
1028 		break;
1029 	case IPV6_RTHDR:
1030 		hdr = (struct ipv6_opt_hdr *)opt->srcrt;
1031 		break;
1032 	case IPV6_DSTOPTS:
1033 		hdr = opt->dst1opt;
1034 		break;
1035 	default:
1036 		return -EINVAL;	/* should not happen */
1037 	}
1038 
1039 	if (!hdr)
1040 		return 0;
1041 
1042 	len = min_t(unsigned int, len, ipv6_optlen(hdr));
1043 	if (copy_to_sockptr(optval, hdr, len))
1044 		return -EFAULT;
1045 	return len;
1046 }
1047 
1048 static int ipv6_get_msfilter(struct sock *sk, sockptr_t optval,
1049 			     sockptr_t optlen, int len)
1050 {
1051 	const int size0 = offsetof(struct group_filter, gf_slist_flex);
1052 	struct group_filter gsf;
1053 	int num;
1054 	int err;
1055 
1056 	if (len < size0)
1057 		return -EINVAL;
1058 	if (copy_from_sockptr(&gsf, optval, size0))
1059 		return -EFAULT;
1060 	if (gsf.gf_group.ss_family != AF_INET6)
1061 		return -EADDRNOTAVAIL;
1062 	num = gsf.gf_numsrc;
1063 	sockopt_lock_sock(sk);
1064 	err = ip6_mc_msfget(sk, &gsf, optval, size0);
1065 	if (!err) {
1066 		if (num > gsf.gf_numsrc)
1067 			num = gsf.gf_numsrc;
1068 		len = GROUP_FILTER_SIZE(num);
1069 		if (copy_to_sockptr(optlen, &len, sizeof(int)) ||
1070 		    copy_to_sockptr(optval, &gsf, size0))
1071 			err = -EFAULT;
1072 	}
1073 	sockopt_release_sock(sk);
1074 	return err;
1075 }
1076 
1077 static int compat_ipv6_get_msfilter(struct sock *sk, sockptr_t optval,
1078 				    sockptr_t optlen, int len)
1079 {
1080 	const int size0 = offsetof(struct compat_group_filter, gf_slist_flex);
1081 	struct compat_group_filter gf32;
1082 	struct group_filter gf;
1083 	int err;
1084 	int num;
1085 
1086 	if (len < size0)
1087 		return -EINVAL;
1088 
1089 	if (copy_from_sockptr(&gf32, optval, size0))
1090 		return -EFAULT;
1091 	gf.gf_interface = gf32.gf_interface;
1092 	gf.gf_fmode = gf32.gf_fmode;
1093 	num = gf.gf_numsrc = gf32.gf_numsrc;
1094 	gf.gf_group = gf32.gf_group;
1095 
1096 	if (gf.gf_group.ss_family != AF_INET6)
1097 		return -EADDRNOTAVAIL;
1098 
1099 	sockopt_lock_sock(sk);
1100 	err = ip6_mc_msfget(sk, &gf, optval, size0);
1101 	sockopt_release_sock(sk);
1102 	if (err)
1103 		return err;
1104 	if (num > gf.gf_numsrc)
1105 		num = gf.gf_numsrc;
1106 	len = GROUP_FILTER_SIZE(num) - (sizeof(gf)-sizeof(gf32));
1107 	if (copy_to_sockptr(optlen, &len, sizeof(int)) ||
1108 	    copy_to_sockptr_offset(optval, offsetof(struct compat_group_filter, gf_fmode),
1109 				   &gf.gf_fmode, sizeof(gf32.gf_fmode)) ||
1110 	    copy_to_sockptr_offset(optval, offsetof(struct compat_group_filter, gf_numsrc),
1111 				   &gf.gf_numsrc, sizeof(gf32.gf_numsrc)))
1112 		return -EFAULT;
1113 	return 0;
1114 }
1115 
1116 int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
1117 		       sockptr_t optval, sockptr_t optlen)
1118 {
1119 	struct ipv6_pinfo *np = inet6_sk(sk);
1120 	int len;
1121 	int val;
1122 
1123 	if (ip6_mroute_opt(optname))
1124 		return ip6_mroute_getsockopt(sk, optname, optval, optlen);
1125 
1126 	if (copy_from_sockptr(&len, optlen, sizeof(int)))
1127 		return -EFAULT;
1128 	switch (optname) {
1129 	case IPV6_ADDRFORM:
1130 		if (sk->sk_protocol != IPPROTO_UDP &&
1131 		    sk->sk_protocol != IPPROTO_UDPLITE &&
1132 		    sk->sk_protocol != IPPROTO_TCP)
1133 			return -ENOPROTOOPT;
1134 		if (sk->sk_state != TCP_ESTABLISHED)
1135 			return -ENOTCONN;
1136 		val = sk->sk_family;
1137 		break;
1138 	case MCAST_MSFILTER:
1139 		if (in_compat_syscall())
1140 			return compat_ipv6_get_msfilter(sk, optval, optlen, len);
1141 		return ipv6_get_msfilter(sk, optval, optlen, len);
1142 	case IPV6_2292PKTOPTIONS:
1143 	{
1144 		struct msghdr msg;
1145 		struct sk_buff *skb;
1146 
1147 		if (sk->sk_type != SOCK_STREAM)
1148 			return -ENOPROTOOPT;
1149 
1150 		if (optval.is_kernel) {
1151 			msg.msg_control_is_user = false;
1152 			msg.msg_control = optval.kernel;
1153 		} else {
1154 			msg.msg_control_is_user = true;
1155 			msg.msg_control_user = optval.user;
1156 		}
1157 		msg.msg_controllen = len;
1158 		msg.msg_flags = 0;
1159 
1160 		sockopt_lock_sock(sk);
1161 		skb = np->pktoptions;
1162 		if (skb)
1163 			ip6_datagram_recv_ctl(sk, &msg, skb);
1164 		sockopt_release_sock(sk);
1165 		if (!skb) {
1166 			if (np->rxopt.bits.rxinfo) {
1167 				struct in6_pktinfo src_info;
1168 				src_info.ipi6_ifindex = np->mcast_oif ? np->mcast_oif :
1169 					np->sticky_pktinfo.ipi6_ifindex;
1170 				src_info.ipi6_addr = np->mcast_oif ? sk->sk_v6_daddr : np->sticky_pktinfo.ipi6_addr;
1171 				put_cmsg(&msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
1172 			}
1173 			if (np->rxopt.bits.rxhlim) {
1174 				int hlim = READ_ONCE(np->mcast_hops);
1175 
1176 				put_cmsg(&msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
1177 			}
1178 			if (np->rxopt.bits.rxtclass) {
1179 				int tclass = (int)ip6_tclass(np->rcv_flowinfo);
1180 
1181 				put_cmsg(&msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
1182 			}
1183 			if (np->rxopt.bits.rxoinfo) {
1184 				struct in6_pktinfo src_info;
1185 				src_info.ipi6_ifindex = np->mcast_oif ? np->mcast_oif :
1186 					np->sticky_pktinfo.ipi6_ifindex;
1187 				src_info.ipi6_addr = np->mcast_oif ? sk->sk_v6_daddr :
1188 								     np->sticky_pktinfo.ipi6_addr;
1189 				put_cmsg(&msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
1190 			}
1191 			if (np->rxopt.bits.rxohlim) {
1192 				int hlim = READ_ONCE(np->mcast_hops);
1193 
1194 				put_cmsg(&msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
1195 			}
1196 			if (np->rxopt.bits.rxflow) {
1197 				__be32 flowinfo = np->rcv_flowinfo;
1198 
1199 				put_cmsg(&msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
1200 			}
1201 		}
1202 		len -= msg.msg_controllen;
1203 		return copy_to_sockptr(optlen, &len, sizeof(int));
1204 	}
1205 	case IPV6_MTU:
1206 	{
1207 		struct dst_entry *dst;
1208 
1209 		val = 0;
1210 		rcu_read_lock();
1211 		dst = __sk_dst_get(sk);
1212 		if (dst)
1213 			val = dst_mtu(dst);
1214 		rcu_read_unlock();
1215 		if (!val)
1216 			return -ENOTCONN;
1217 		break;
1218 	}
1219 
1220 	case IPV6_V6ONLY:
1221 		val = sk->sk_ipv6only;
1222 		break;
1223 
1224 	case IPV6_RECVPKTINFO:
1225 		val = np->rxopt.bits.rxinfo;
1226 		break;
1227 
1228 	case IPV6_2292PKTINFO:
1229 		val = np->rxopt.bits.rxoinfo;
1230 		break;
1231 
1232 	case IPV6_RECVHOPLIMIT:
1233 		val = np->rxopt.bits.rxhlim;
1234 		break;
1235 
1236 	case IPV6_2292HOPLIMIT:
1237 		val = np->rxopt.bits.rxohlim;
1238 		break;
1239 
1240 	case IPV6_RECVRTHDR:
1241 		val = np->rxopt.bits.srcrt;
1242 		break;
1243 
1244 	case IPV6_2292RTHDR:
1245 		val = np->rxopt.bits.osrcrt;
1246 		break;
1247 
1248 	case IPV6_HOPOPTS:
1249 	case IPV6_RTHDRDSTOPTS:
1250 	case IPV6_RTHDR:
1251 	case IPV6_DSTOPTS:
1252 	{
1253 		struct ipv6_txoptions *opt;
1254 
1255 		sockopt_lock_sock(sk);
1256 		opt = rcu_dereference_protected(np->opt,
1257 						lockdep_sock_is_held(sk));
1258 		len = ipv6_getsockopt_sticky(sk, opt, optname, optval, len);
1259 		sockopt_release_sock(sk);
1260 		/* check if ipv6_getsockopt_sticky() returns err code */
1261 		if (len < 0)
1262 			return len;
1263 		return copy_to_sockptr(optlen, &len, sizeof(int));
1264 	}
1265 
1266 	case IPV6_RECVHOPOPTS:
1267 		val = np->rxopt.bits.hopopts;
1268 		break;
1269 
1270 	case IPV6_2292HOPOPTS:
1271 		val = np->rxopt.bits.ohopopts;
1272 		break;
1273 
1274 	case IPV6_RECVDSTOPTS:
1275 		val = np->rxopt.bits.dstopts;
1276 		break;
1277 
1278 	case IPV6_2292DSTOPTS:
1279 		val = np->rxopt.bits.odstopts;
1280 		break;
1281 
1282 	case IPV6_TCLASS:
1283 		val = np->tclass;
1284 		break;
1285 
1286 	case IPV6_RECVTCLASS:
1287 		val = np->rxopt.bits.rxtclass;
1288 		break;
1289 
1290 	case IPV6_FLOWINFO:
1291 		val = np->rxopt.bits.rxflow;
1292 		break;
1293 
1294 	case IPV6_RECVPATHMTU:
1295 		val = np->rxopt.bits.rxpmtu;
1296 		break;
1297 
1298 	case IPV6_PATHMTU:
1299 	{
1300 		struct dst_entry *dst;
1301 		struct ip6_mtuinfo mtuinfo;
1302 
1303 		if (len < sizeof(mtuinfo))
1304 			return -EINVAL;
1305 
1306 		len = sizeof(mtuinfo);
1307 		memset(&mtuinfo, 0, sizeof(mtuinfo));
1308 
1309 		rcu_read_lock();
1310 		dst = __sk_dst_get(sk);
1311 		if (dst)
1312 			mtuinfo.ip6m_mtu = dst_mtu(dst);
1313 		rcu_read_unlock();
1314 		if (!mtuinfo.ip6m_mtu)
1315 			return -ENOTCONN;
1316 
1317 		if (copy_to_sockptr(optlen, &len, sizeof(int)))
1318 			return -EFAULT;
1319 		if (copy_to_sockptr(optval, &mtuinfo, len))
1320 			return -EFAULT;
1321 
1322 		return 0;
1323 	}
1324 
1325 	case IPV6_TRANSPARENT:
1326 		val = inet_test_bit(TRANSPARENT, sk);
1327 		break;
1328 
1329 	case IPV6_FREEBIND:
1330 		val = inet_test_bit(FREEBIND, sk);
1331 		break;
1332 
1333 	case IPV6_RECVORIGDSTADDR:
1334 		val = np->rxopt.bits.rxorigdstaddr;
1335 		break;
1336 
1337 	case IPV6_UNICAST_HOPS:
1338 	case IPV6_MULTICAST_HOPS:
1339 	{
1340 		struct dst_entry *dst;
1341 
1342 		if (optname == IPV6_UNICAST_HOPS)
1343 			val = READ_ONCE(np->hop_limit);
1344 		else
1345 			val = READ_ONCE(np->mcast_hops);
1346 
1347 		if (val < 0) {
1348 			rcu_read_lock();
1349 			dst = __sk_dst_get(sk);
1350 			if (dst)
1351 				val = ip6_dst_hoplimit(dst);
1352 			rcu_read_unlock();
1353 		}
1354 
1355 		if (val < 0)
1356 			val = sock_net(sk)->ipv6.devconf_all->hop_limit;
1357 		break;
1358 	}
1359 
1360 	case IPV6_MULTICAST_LOOP:
1361 		val = inet6_test_bit(MC6_LOOP, sk);
1362 		break;
1363 
1364 	case IPV6_MULTICAST_IF:
1365 		val = np->mcast_oif;
1366 		break;
1367 
1368 	case IPV6_MULTICAST_ALL:
1369 		val = inet6_test_bit(MC6_ALL, sk);
1370 		break;
1371 
1372 	case IPV6_UNICAST_IF:
1373 		val = (__force int)htonl((__u32) np->ucast_oif);
1374 		break;
1375 
1376 	case IPV6_MTU_DISCOVER:
1377 		val = np->pmtudisc;
1378 		break;
1379 
1380 	case IPV6_RECVERR:
1381 		val = inet6_test_bit(RECVERR6, sk);
1382 		break;
1383 
1384 	case IPV6_FLOWINFO_SEND:
1385 		val = np->sndflow;
1386 		break;
1387 
1388 	case IPV6_FLOWLABEL_MGR:
1389 	{
1390 		struct in6_flowlabel_req freq;
1391 		int flags;
1392 
1393 		if (len < sizeof(freq))
1394 			return -EINVAL;
1395 
1396 		if (copy_from_sockptr(&freq, optval, sizeof(freq)))
1397 			return -EFAULT;
1398 
1399 		if (freq.flr_action != IPV6_FL_A_GET)
1400 			return -EINVAL;
1401 
1402 		len = sizeof(freq);
1403 		flags = freq.flr_flags;
1404 
1405 		memset(&freq, 0, sizeof(freq));
1406 
1407 		val = ipv6_flowlabel_opt_get(sk, &freq, flags);
1408 		if (val < 0)
1409 			return val;
1410 
1411 		if (copy_to_sockptr(optlen, &len, sizeof(int)))
1412 			return -EFAULT;
1413 		if (copy_to_sockptr(optval, &freq, len))
1414 			return -EFAULT;
1415 
1416 		return 0;
1417 	}
1418 
1419 	case IPV6_ADDR_PREFERENCES:
1420 		val = 0;
1421 
1422 		if (np->srcprefs & IPV6_PREFER_SRC_TMP)
1423 			val |= IPV6_PREFER_SRC_TMP;
1424 		else if (np->srcprefs & IPV6_PREFER_SRC_PUBLIC)
1425 			val |= IPV6_PREFER_SRC_PUBLIC;
1426 		else {
1427 			/* XXX: should we return system default? */
1428 			val |= IPV6_PREFER_SRC_PUBTMP_DEFAULT;
1429 		}
1430 
1431 		if (np->srcprefs & IPV6_PREFER_SRC_COA)
1432 			val |= IPV6_PREFER_SRC_COA;
1433 		else
1434 			val |= IPV6_PREFER_SRC_HOME;
1435 		break;
1436 
1437 	case IPV6_MINHOPCOUNT:
1438 		val = READ_ONCE(np->min_hopcount);
1439 		break;
1440 
1441 	case IPV6_DONTFRAG:
1442 		val = inet6_test_bit(DONTFRAG, sk);
1443 		break;
1444 
1445 	case IPV6_AUTOFLOWLABEL:
1446 		val = ip6_autoflowlabel(sock_net(sk), sk);
1447 		break;
1448 
1449 	case IPV6_RECVFRAGSIZE:
1450 		val = np->rxopt.bits.recvfragsize;
1451 		break;
1452 
1453 	case IPV6_ROUTER_ALERT_ISOLATE:
1454 		val = inet6_test_bit(RTALERT_ISOLATE, sk);
1455 		break;
1456 
1457 	case IPV6_RECVERR_RFC4884:
1458 		val = inet6_test_bit(RECVERR6_RFC4884, sk);
1459 		break;
1460 
1461 	default:
1462 		return -ENOPROTOOPT;
1463 	}
1464 	len = min_t(unsigned int, sizeof(int), len);
1465 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
1466 		return -EFAULT;
1467 	if (copy_to_sockptr(optval, &val, len))
1468 		return -EFAULT;
1469 	return 0;
1470 }
1471 
1472 int ipv6_getsockopt(struct sock *sk, int level, int optname,
1473 		    char __user *optval, int __user *optlen)
1474 {
1475 	int err;
1476 
1477 	if (level == SOL_IP && sk->sk_type != SOCK_RAW)
1478 		return udp_prot.getsockopt(sk, level, optname, optval, optlen);
1479 
1480 	if (level != SOL_IPV6)
1481 		return -ENOPROTOOPT;
1482 
1483 	err = do_ipv6_getsockopt(sk, level, optname,
1484 				 USER_SOCKPTR(optval), USER_SOCKPTR(optlen));
1485 #ifdef CONFIG_NETFILTER
1486 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1487 	if (err == -ENOPROTOOPT && optname != IPV6_2292PKTOPTIONS) {
1488 		int len;
1489 
1490 		if (get_user(len, optlen))
1491 			return -EFAULT;
1492 
1493 		err = nf_getsockopt(sk, PF_INET6, optname, optval, &len);
1494 		if (err >= 0)
1495 			err = put_user(len, optlen);
1496 	}
1497 #endif
1498 	return err;
1499 }
1500 EXPORT_SYMBOL(ipv6_getsockopt);
1501