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(size: 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(objp: 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(objp: 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(dst: &gr32, src: optval, size: 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(dst: greqs, src: optval, size: 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: &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, ifindex: greqs.gsr_interface,
191	addr: &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, pgsr: &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(src: optval, len: optlen);
217	if (IS_ERR(ptr: gsf))
218	return PTR_ERR(ptr: 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, list: gsf->gf_slist_flex);
231	out_free_gsf:
232	kfree(objp: 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(size: 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(dst: gf32, src: optval, size: 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, gsf: &(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}, list: gf32->gf_slist_flex);
274
275	out_free_p:
276	kfree(objp: 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(dst: &greq, src: optval, size: 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, ifindex: greq.gr_interface,
296	addr: &psin6->sin6_addr);
297	return ipv6_sock_mc_drop(sk, ifindex: greq.gr_interface, addr: &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(dst: &gr32, src: optval, size: 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, ifindex: gr32.gr_interface,
316	addr: &psin6->sin6_addr);
317	return ipv6_sock_mc_drop(sk, ifindex: gr32.gr_interface, addr: &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: 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(ns: 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(sockptr: 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(src: optval, len: optlen);
345	if (IS_ERR(ptr: new))
346	return PTR_ERR(ptr: new);
347	if (unlikely(ipv6_optlen(new) > optlen)) {
348	kfree(objp: 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, newtype: optname, newopt: new);
355	kfree(objp: new);
356	if (IS_ERR(ptr: opt))
357	return PTR_ERR(ptr: 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, len: optlen, reduced: 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(i: opt->tot_len, v: &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: 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(sockptr: optval))
404	val = 0;
405	else {
406	if (optlen >= sizeof(int)) {
407	if (copy_from_sockptr(dst: &val, src: optval, size: sizeof(val)))
408	return -EFAULT;
409	} else
410	val = 0;
411	}
412
413	valbool = (val != 0);
414
415	if (ip6_mroute_opt(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(list: &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	case IPV6_MTU_DISCOVER:
497	if (optlen < sizeof(int))
498	return -EINVAL;
499	if (val < IPV6_PMTUDISC_DONT || val > IPV6_PMTUDISC_OMIT)
500	return -EINVAL;
501	WRITE_ONCE(np->pmtudisc, val);
502	return 0;
503	case IPV6_FLOWINFO_SEND:
504	if (optlen < sizeof(int))
505	return -EINVAL;
506	inet6_assign_bit(SNDFLOW, sk, valbool);
507	return 0;
508	case IPV6_ADDR_PREFERENCES:
509	if (optlen < sizeof(int))
510	return -EINVAL;
511	return ip6_sock_set_addr_preferences(sk, val);
512	}
513	if (needs_rtnl)
514	rtnl_lock();
515	sockopt_lock_sock(sk);
516
517	/* Another thread has converted the socket into IPv4 with
518	* IPV6_ADDRFORM concurrently.
519	*/
520	if (unlikely(sk->sk_family != AF_INET6))
521	goto unlock;
522
523	switch (optname) {
524
525	case IPV6_ADDRFORM:
526	if (optlen < sizeof(int))
527	goto e_inval;
528	if (val == PF_INET) {
529	if (sk->sk_type == SOCK_RAW)
530	break;
531
532	if (sk->sk_protocol == IPPROTO_UDP ||
533	sk->sk_protocol == IPPROTO_UDPLITE) {
534	struct udp_sock *up = udp_sk(sk);
535	if (up->pending == AF_INET6) {
536	retv = -EBUSY;
537	break;
538	}
539	} else if (sk->sk_protocol == IPPROTO_TCP) {
540	if (sk->sk_prot != &tcpv6_prot) {
541	retv = -EBUSY;
542	break;
543	}
544	} else {
545	break;
546	}
547
548	if (sk->sk_state != TCP_ESTABLISHED) {
549	retv = -ENOTCONN;
550	break;
551	}
552
553	if (ipv6_only_sock(sk) ||
554	!ipv6_addr_v4mapped(a: &sk->sk_v6_daddr)) {
555	retv = -EADDRNOTAVAIL;
556	break;
557	}
558
559	__ipv6_sock_mc_close(sk);
560	__ipv6_sock_ac_close(sk);
561
562	if (sk->sk_protocol == IPPROTO_TCP) {
563	struct inet_connection_sock *icsk = inet_csk(sk);
564
565	sock_prot_inuse_add(net, prot: sk->sk_prot, val: -1);
566	sock_prot_inuse_add(net, prot: &tcp_prot, val: 1);
567
568	/* Paired with READ_ONCE(sk->sk_prot) in inet6_stream_ops */
569	WRITE_ONCE(sk->sk_prot, &tcp_prot);
570	/* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
571	WRITE_ONCE(icsk->icsk_af_ops, &ipv4_specific);
572	WRITE_ONCE(sk->sk_socket->ops, &inet_stream_ops);
573	WRITE_ONCE(sk->sk_family, PF_INET);
574	tcp_sync_mss(sk, pmtu: icsk->icsk_pmtu_cookie);
575	} else {
576	struct proto *prot = &udp_prot;
577
578	if (sk->sk_protocol == IPPROTO_UDPLITE)
579	prot = &udplite_prot;
580
581	sock_prot_inuse_add(net, prot: sk->sk_prot, val: -1);
582	sock_prot_inuse_add(net, prot, val: 1);
583
584	/* Paired with READ_ONCE(sk->sk_prot) in inet6_dgram_ops */
585	WRITE_ONCE(sk->sk_prot, prot);
586	WRITE_ONCE(sk->sk_socket->ops, &inet_dgram_ops);
587	WRITE_ONCE(sk->sk_family, PF_INET);
588	}
589
590	/* Disable all options not to allocate memory anymore,
591	* but there is still a race. See the lockless path
592	* in udpv6_sendmsg() and ipv6_local_rxpmtu().
593	*/
594	np->rxopt.all = 0;
595
596	inet6_cleanup_sock(sk);
597
598	module_put(THIS_MODULE);
599	retv = 0;
600	break;
601	}
602	goto e_inval;
603
604	case IPV6_V6ONLY:
605	if (optlen < sizeof(int) ||
606	inet_sk(sk)->inet_num)
607	goto e_inval;
608	sk->sk_ipv6only = valbool;
609	retv = 0;
610	break;
611
612	case IPV6_RECVPKTINFO:
613	if (optlen < sizeof(int))
614	goto e_inval;
615	np->rxopt.bits.rxinfo = valbool;
616	retv = 0;
617	break;
618
619	case IPV6_2292PKTINFO:
620	if (optlen < sizeof(int))
621	goto e_inval;
622	np->rxopt.bits.rxoinfo = valbool;
623	retv = 0;
624	break;
625
626	case IPV6_RECVHOPLIMIT:
627	if (optlen < sizeof(int))
628	goto e_inval;
629	np->rxopt.bits.rxhlim = valbool;
630	retv = 0;
631	break;
632
633	case IPV6_2292HOPLIMIT:
634	if (optlen < sizeof(int))
635	goto e_inval;
636	np->rxopt.bits.rxohlim = valbool;
637	retv = 0;
638	break;
639
640	case IPV6_RECVRTHDR:
641	if (optlen < sizeof(int))
642	goto e_inval;
643	np->rxopt.bits.srcrt = valbool;
644	retv = 0;
645	break;
646
647	case IPV6_2292RTHDR:
648	if (optlen < sizeof(int))
649	goto e_inval;
650	np->rxopt.bits.osrcrt = valbool;
651	retv = 0;
652	break;
653
654	case IPV6_RECVHOPOPTS:
655	if (optlen < sizeof(int))
656	goto e_inval;
657	np->rxopt.bits.hopopts = valbool;
658	retv = 0;
659	break;
660
661	case IPV6_2292HOPOPTS:
662	if (optlen < sizeof(int))
663	goto e_inval;
664	np->rxopt.bits.ohopopts = valbool;
665	retv = 0;
666	break;
667
668	case IPV6_RECVDSTOPTS:
669	if (optlen < sizeof(int))
670	goto e_inval;
671	np->rxopt.bits.dstopts = valbool;
672	retv = 0;
673	break;
674
675	case IPV6_2292DSTOPTS:
676	if (optlen < sizeof(int))
677	goto e_inval;
678	np->rxopt.bits.odstopts = valbool;
679	retv = 0;
680	break;
681
682	case IPV6_TCLASS:
683	if (optlen < sizeof(int))
684	goto e_inval;
685	if (val < -1 || val > 0xff)
686	goto e_inval;
687	/* RFC 3542, 6.5: default traffic class of 0x0 */
688	if (val == -1)
689	val = 0;
690	if (sk->sk_type == SOCK_STREAM) {
691	val &= ~INET_ECN_MASK;
692	val |= np->tclass & INET_ECN_MASK;
693	}
694	if (np->tclass != val) {
695	np->tclass = val;
696	sk_dst_reset(sk);
697	}
698	retv = 0;
699	break;
700
701	case IPV6_RECVTCLASS:
702	if (optlen < sizeof(int))
703	goto e_inval;
704	np->rxopt.bits.rxtclass = valbool;
705	retv = 0;
706	break;
707
708	case IPV6_FLOWINFO:
709	if (optlen < sizeof(int))
710	goto e_inval;
711	np->rxopt.bits.rxflow = valbool;
712	retv = 0;
713	break;
714
715	case IPV6_RECVPATHMTU:
716	if (optlen < sizeof(int))
717	goto e_inval;
718	np->rxopt.bits.rxpmtu = valbool;
719	retv = 0;
720	break;
721
722	case IPV6_TRANSPARENT:
723	if (valbool && !sockopt_ns_capable(ns: net->user_ns, CAP_NET_RAW) &&
724	!sockopt_ns_capable(ns: net->user_ns, CAP_NET_ADMIN)) {
725	retv = -EPERM;
726	break;
727	}
728	if (optlen < sizeof(int))
729	goto e_inval;
730	/* we don't have a separate transparent bit for IPV6 we use the one in the IPv4 socket */
731	inet_assign_bit(TRANSPARENT, sk, valbool);
732	retv = 0;
733	break;
734
735	case IPV6_FREEBIND:
736	if (optlen < sizeof(int))
737	goto e_inval;
738	/* we also don't have a separate freebind bit for IPV6 */
739	inet_assign_bit(FREEBIND, sk, valbool);
740	retv = 0;
741	break;
742
743	case IPV6_RECVORIGDSTADDR:
744	if (optlen < sizeof(int))
745	goto e_inval;
746	np->rxopt.bits.rxorigdstaddr = valbool;
747	retv = 0;
748	break;
749
750	case IPV6_HOPOPTS:
751	case IPV6_RTHDRDSTOPTS:
752	case IPV6_RTHDR:
753	case IPV6_DSTOPTS:
754	retv = ipv6_set_opt_hdr(sk, optname, optval, optlen);
755	break;
756
757	case IPV6_PKTINFO:
758	{
759	struct in6_pktinfo pkt;
760
761	if (optlen == 0)
762	goto e_inval;
763	else if (optlen < sizeof(struct in6_pktinfo) ||
764	sockptr_is_null(sockptr: optval))
765	goto e_inval;
766
767	if (copy_from_sockptr(dst: &pkt, src: optval, size: sizeof(pkt))) {
768	retv = -EFAULT;
769	break;
770	}
771	if (!sk_dev_equal_l3scope(sk, dif: pkt.ipi6_ifindex))
772	goto e_inval;
773
774	np->sticky_pktinfo.ipi6_ifindex = pkt.ipi6_ifindex;
775	np->sticky_pktinfo.ipi6_addr = pkt.ipi6_addr;
776	retv = 0;
777	break;
778	}
779
780	case IPV6_2292PKTOPTIONS:
781	{
782	struct ipv6_txoptions *opt = NULL;
783	struct msghdr msg;
784	struct flowi6 fl6;
785	struct ipcm6_cookie ipc6;
786
787	memset(&fl6, 0, sizeof(fl6));
788	fl6.flowi6_oif = sk->sk_bound_dev_if;
789	fl6.flowi6_mark = sk->sk_mark;
790
791	if (optlen == 0)
792	goto update;
793
794	/* 1K is probably excessive
795	* 1K is surely not enough, 2K per standard header is 16K.
796	*/
797	retv = -EINVAL;
798	if (optlen > 64*1024)
799	break;
800
801	opt = sock_kmalloc(sk, size: sizeof(*opt) + optlen, GFP_KERNEL);
802	retv = -ENOBUFS;
803	if (!opt)
804	break;
805
806	memset(opt, 0, sizeof(*opt));
807	refcount_set(r: &opt->refcnt, n: 1);
808	opt->tot_len = sizeof(*opt) + optlen;
809	retv = -EFAULT;
810	if (copy_from_sockptr(dst: opt + 1, src: optval, size: optlen))
811	goto done;
812
813	msg.msg_controllen = optlen;
814	msg.msg_control_is_user = false;
815	msg.msg_control = (void *)(opt+1);
816	ipc6.opt = opt;
817
818	retv = ip6_datagram_send_ctl(net, sk, msg: &msg, fl6: &fl6, ipc6: &ipc6);
819	if (retv)
820	goto done;
821	update:
822	retv = 0;
823	opt = ipv6_update_options(sk, opt);
824	done:
825	if (opt) {
826	atomic_sub(i: opt->tot_len, v: &sk->sk_omem_alloc);
827	txopt_put(opt);
828	}
829	break;
830	}
831
832
833	case IPV6_UNICAST_IF:
834	{
835	struct net_device *dev = NULL;
836	int ifindex;
837
838	if (optlen != sizeof(int))
839	goto e_inval;
840
841	ifindex = (__force int)ntohl((__force __be32)val);
842	if (ifindex == 0) {
843	np->ucast_oif = 0;
844	retv = 0;
845	break;
846	}
847
848	dev = dev_get_by_index(net, ifindex);
849	retv = -EADDRNOTAVAIL;
850	if (!dev)
851	break;
852	dev_put(dev);
853
854	retv = -EINVAL;
855	if (sk->sk_bound_dev_if)
856	break;
857
858	np->ucast_oif = ifindex;
859	retv = 0;
860	break;
861	}
862
863	case IPV6_MULTICAST_IF:
864	if (sk->sk_type == SOCK_STREAM)
865	break;
866	if (optlen < sizeof(int))
867	goto e_inval;
868
869	if (val) {
870	struct net_device *dev;
871	int midx;
872
873	rcu_read_lock();
874
875	dev = dev_get_by_index_rcu(net, ifindex: val);
876	if (!dev) {
877	rcu_read_unlock();
878	retv = -ENODEV;
879	break;
880	}
881	midx = l3mdev_master_ifindex_rcu(dev);
882
883	rcu_read_unlock();
884
885	if (sk->sk_bound_dev_if &&
886	sk->sk_bound_dev_if != val &&
887	(!midx || midx != sk->sk_bound_dev_if))
888	goto e_inval;
889	}
890	np->mcast_oif = val;
891	retv = 0;
892	break;
893	case IPV6_ADD_MEMBERSHIP:
894	case IPV6_DROP_MEMBERSHIP:
895	{
896	struct ipv6_mreq mreq;
897
898	if (optlen < sizeof(struct ipv6_mreq))
899	goto e_inval;
900
901	retv = -EPROTO;
902	if (inet_test_bit(IS_ICSK, sk))
903	break;
904
905	retv = -EFAULT;
906	if (copy_from_sockptr(dst: &mreq, src: optval, size: sizeof(struct ipv6_mreq)))
907	break;
908
909	if (optname == IPV6_ADD_MEMBERSHIP)
910	retv = ipv6_sock_mc_join(sk, ifindex: mreq.ipv6mr_ifindex, addr: &mreq.ipv6mr_multiaddr);
911	else
912	retv = ipv6_sock_mc_drop(sk, ifindex: mreq.ipv6mr_ifindex, addr: &mreq.ipv6mr_multiaddr);
913	break;
914	}
915	case IPV6_JOIN_ANYCAST:
916	case IPV6_LEAVE_ANYCAST:
917	{
918	struct ipv6_mreq mreq;
919
920	if (optlen < sizeof(struct ipv6_mreq))
921	goto e_inval;
922
923	retv = -EFAULT;
924	if (copy_from_sockptr(dst: &mreq, src: optval, size: sizeof(struct ipv6_mreq)))
925	break;
926
927	if (optname == IPV6_JOIN_ANYCAST)
928	retv = ipv6_sock_ac_join(sk, ifindex: mreq.ipv6mr_ifindex, addr: &mreq.ipv6mr_acaddr);
929	else
930	retv = ipv6_sock_ac_drop(sk, ifindex: mreq.ipv6mr_ifindex, addr: &mreq.ipv6mr_acaddr);
931	break;
932	}
933	case MCAST_JOIN_GROUP:
934	case MCAST_LEAVE_GROUP:
935	if (in_compat_syscall())
936	retv = compat_ipv6_mcast_join_leave(sk, optname, optval,
937	optlen);
938	else
939	retv = ipv6_mcast_join_leave(sk, optname, optval,
940	optlen);
941	break;
942	case MCAST_JOIN_SOURCE_GROUP:
943	case MCAST_LEAVE_SOURCE_GROUP:
944	case MCAST_BLOCK_SOURCE:
945	case MCAST_UNBLOCK_SOURCE:
946	retv = do_ipv6_mcast_group_source(sk, optname, optval, optlen);
947	break;
948	case MCAST_MSFILTER:
949	if (in_compat_syscall())
950	retv = compat_ipv6_set_mcast_msfilter(sk, optval,
951	optlen);
952	else
953	retv = ipv6_set_mcast_msfilter(sk, optval, optlen);
954	break;
955	case IPV6_ROUTER_ALERT:
956	if (optlen < sizeof(int))
957	goto e_inval;
958	retv = ip6_ra_control(sk, sel: val);
959	break;
960	case IPV6_FLOWLABEL_MGR:
961	retv = ipv6_flowlabel_opt(sk, optval, optlen);
962	break;
963	case IPV6_IPSEC_POLICY:
964	case IPV6_XFRM_POLICY:
965	retv = -EPERM;
966	if (!sockopt_ns_capable(ns: net->user_ns, CAP_NET_ADMIN))
967	break;
968	retv = xfrm_user_policy(sk, optname, optval, optlen);
969	break;
970
971	case IPV6_RECVFRAGSIZE:
972	np->rxopt.bits.recvfragsize = valbool;
973	retv = 0;
974	break;
975	}
976
977	unlock:
978	sockopt_release_sock(sk);
979	if (needs_rtnl)
980	rtnl_unlock();
981
982	return retv;
983
984	e_inval:
985	retv = -EINVAL;
986	goto unlock;
987	}
988
989	int ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
990	unsigned int optlen)
991	{
992	int err;
993
994	if (level == SOL_IP && sk->sk_type != SOCK_RAW)
995	return udp_prot.setsockopt(sk, level, optname, optval, optlen);
996
997	if (level != SOL_IPV6)
998	return -ENOPROTOOPT;
999
1000	err = do_ipv6_setsockopt(sk, level, optname, optval, optlen);
1001	#ifdef CONFIG_NETFILTER
1002	/* we need to exclude all possible ENOPROTOOPTs except default case */
1003	if (err == -ENOPROTOOPT && optname != IPV6_IPSEC_POLICY &&
1004	optname != IPV6_XFRM_POLICY)
1005	err = nf_setsockopt(sk, PF_INET6, optval: optname, opt: optval, len: optlen);
1006	#endif
1007	return err;
1008	}
1009	EXPORT_SYMBOL(ipv6_setsockopt);
1010
1011	static int ipv6_getsockopt_sticky(struct sock *sk, struct ipv6_txoptions *opt,
1012	int optname, sockptr_t optval, int len)
1013	{
1014	struct ipv6_opt_hdr *hdr;
1015
1016	if (!opt)
1017	return 0;
1018
1019	switch (optname) {
1020	case IPV6_HOPOPTS:
1021	hdr = opt->hopopt;
1022	break;
1023	case IPV6_RTHDRDSTOPTS:
1024	hdr = opt->dst0opt;
1025	break;
1026	case IPV6_RTHDR:
1027	hdr = (struct ipv6_opt_hdr *)opt->srcrt;
1028	break;
1029	case IPV6_DSTOPTS:
1030	hdr = opt->dst1opt;
1031	break;
1032	default:
1033	return -EINVAL; /* should not happen */
1034	}
1035
1036	if (!hdr)
1037	return 0;
1038
1039	len = min_t(unsigned int, len, ipv6_optlen(hdr));
1040	if (copy_to_sockptr(dst: optval, src: hdr, size: len))
1041	return -EFAULT;
1042	return len;
1043	}
1044
1045	static int ipv6_get_msfilter(struct sock *sk, sockptr_t optval,
1046	sockptr_t optlen, int len)
1047	{
1048	const int size0 = offsetof(struct group_filter, gf_slist_flex);
1049	struct group_filter gsf;
1050	int num;
1051	int err;
1052
1053	if (len < size0)
1054	return -EINVAL;
1055	if (copy_from_sockptr(dst: &gsf, src: optval, size: size0))
1056	return -EFAULT;
1057	if (gsf.gf_group.ss_family != AF_INET6)
1058	return -EADDRNOTAVAIL;
1059	num = gsf.gf_numsrc;
1060	sockopt_lock_sock(sk);
1061	err = ip6_mc_msfget(sk, gsf: &gsf, optval, ss_offset: size0);
1062	if (!err) {
1063	if (num > gsf.gf_numsrc)
1064	num = gsf.gf_numsrc;
1065	len = GROUP_FILTER_SIZE(num);
1066	if (copy_to_sockptr(dst: optlen, src: &len, size: sizeof(int)) ||
1067	copy_to_sockptr(dst: optval, src: &gsf, size: size0))
1068	err = -EFAULT;
1069	}
1070	sockopt_release_sock(sk);
1071	return err;
1072	}
1073
1074	static int compat_ipv6_get_msfilter(struct sock *sk, sockptr_t optval,
1075	sockptr_t optlen, int len)
1076	{
1077	const int size0 = offsetof(struct compat_group_filter, gf_slist_flex);
1078	struct compat_group_filter gf32;
1079	struct group_filter gf;
1080	int err;
1081	int num;
1082
1083	if (len < size0)
1084	return -EINVAL;
1085
1086	if (copy_from_sockptr(dst: &gf32, src: optval, size: size0))
1087	return -EFAULT;
1088	gf.gf_interface = gf32.gf_interface;
1089	gf.gf_fmode = gf32.gf_fmode;
1090	num = gf.gf_numsrc = gf32.gf_numsrc;
1091	gf.gf_group = gf32.gf_group;
1092
1093	if (gf.gf_group.ss_family != AF_INET6)
1094	return -EADDRNOTAVAIL;
1095
1096	sockopt_lock_sock(sk);
1097	err = ip6_mc_msfget(sk, gsf: &gf, optval, ss_offset: size0);
1098	sockopt_release_sock(sk);
1099	if (err)
1100	return err;
1101	if (num > gf.gf_numsrc)
1102	num = gf.gf_numsrc;
1103	len = GROUP_FILTER_SIZE(num) - (sizeof(gf)-sizeof(gf32));
1104	if (copy_to_sockptr(dst: optlen, src: &len, size: sizeof(int)) ||
1105	copy_to_sockptr_offset(dst: optval, offsetof(struct compat_group_filter, gf_fmode),
1106	src: &gf.gf_fmode, size: sizeof(gf32.gf_fmode)) ||
1107	copy_to_sockptr_offset(dst: optval, offsetof(struct compat_group_filter, gf_numsrc),
1108	src: &gf.gf_numsrc, size: sizeof(gf32.gf_numsrc)))
1109	return -EFAULT;
1110	return 0;
1111	}
1112
1113	int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
1114	sockptr_t optval, sockptr_t optlen)
1115	{
1116	struct ipv6_pinfo *np = inet6_sk(sk: sk);
1117	int len;
1118	int val;
1119
1120	if (ip6_mroute_opt(opt: optname))
1121	return ip6_mroute_getsockopt(sk, optname, optval, optlen);
1122
1123	if (copy_from_sockptr(dst: &len, src: optlen, size: sizeof(int)))
1124	return -EFAULT;
1125	switch (optname) {
1126	case IPV6_ADDRFORM:
1127	if (sk->sk_protocol != IPPROTO_UDP &&
1128	sk->sk_protocol != IPPROTO_UDPLITE &&
1129	sk->sk_protocol != IPPROTO_TCP)
1130	return -ENOPROTOOPT;
1131	if (sk->sk_state != TCP_ESTABLISHED)
1132	return -ENOTCONN;
1133	val = sk->sk_family;
1134	break;
1135	case MCAST_MSFILTER:
1136	if (in_compat_syscall())
1137	return compat_ipv6_get_msfilter(sk, optval, optlen, len);
1138	return ipv6_get_msfilter(sk, optval, optlen, len);
1139	case IPV6_2292PKTOPTIONS:
1140	{
1141	struct msghdr msg;
1142	struct sk_buff *skb;
1143
1144	if (sk->sk_type != SOCK_STREAM)
1145	return -ENOPROTOOPT;
1146
1147	if (optval.is_kernel) {
1148	msg.msg_control_is_user = false;
1149	msg.msg_control = optval.kernel;
1150	} else {
1151	msg.msg_control_is_user = true;
1152	msg.msg_control_user = optval.user;
1153	}
1154	msg.msg_controllen = len;
1155	msg.msg_flags = 0;
1156
1157	sockopt_lock_sock(sk);
1158	skb = np->pktoptions;
1159	if (skb)
1160	ip6_datagram_recv_ctl(sk, msg: &msg, skb);
1161	sockopt_release_sock(sk);
1162	if (!skb) {
1163	if (np->rxopt.bits.rxinfo) {
1164	struct in6_pktinfo src_info;
1165	src_info.ipi6_ifindex = np->mcast_oif ? np->mcast_oif :
1166	np->sticky_pktinfo.ipi6_ifindex;
1167	src_info.ipi6_addr = np->mcast_oif ? sk->sk_v6_daddr : np->sticky_pktinfo.ipi6_addr;
1168	put_cmsg(&msg, SOL_IPV6, IPV6_PKTINFO, len: sizeof(src_info), data: &src_info);
1169	}
1170	if (np->rxopt.bits.rxhlim) {
1171	int hlim = READ_ONCE(np->mcast_hops);
1172
1173	put_cmsg(&msg, SOL_IPV6, IPV6_HOPLIMIT, len: sizeof(hlim), data: &hlim);
1174	}
1175	if (np->rxopt.bits.rxtclass) {
1176	int tclass = (int)ip6_tclass(flowinfo: np->rcv_flowinfo);
1177
1178	put_cmsg(&msg, SOL_IPV6, IPV6_TCLASS, len: sizeof(tclass), data: &tclass);
1179	}
1180	if (np->rxopt.bits.rxoinfo) {
1181	struct in6_pktinfo src_info;
1182	src_info.ipi6_ifindex = np->mcast_oif ? np->mcast_oif :
1183	np->sticky_pktinfo.ipi6_ifindex;
1184	src_info.ipi6_addr = np->mcast_oif ? sk->sk_v6_daddr :
1185	np->sticky_pktinfo.ipi6_addr;
1186	put_cmsg(&msg, SOL_IPV6, IPV6_2292PKTINFO, len: sizeof(src_info), data: &src_info);
1187	}
1188	if (np->rxopt.bits.rxohlim) {
1189	int hlim = READ_ONCE(np->mcast_hops);
1190
1191	put_cmsg(&msg, SOL_IPV6, IPV6_2292HOPLIMIT, len: sizeof(hlim), data: &hlim);
1192	}
1193	if (np->rxopt.bits.rxflow) {
1194	__be32 flowinfo = np->rcv_flowinfo;
1195
1196	put_cmsg(&msg, SOL_IPV6, IPV6_FLOWINFO, len: sizeof(flowinfo), data: &flowinfo);
1197	}
1198	}
1199	len -= msg.msg_controllen;
1200	return copy_to_sockptr(dst: optlen, src: &len, size: sizeof(int));
1201	}
1202	case IPV6_MTU:
1203	{
1204	struct dst_entry *dst;
1205
1206	val = 0;
1207	rcu_read_lock();
1208	dst = __sk_dst_get(sk);
1209	if (dst)
1210	val = dst_mtu(dst);
1211	rcu_read_unlock();
1212	if (!val)
1213	return -ENOTCONN;
1214	break;
1215	}
1216
1217	case IPV6_V6ONLY:
1218	val = sk->sk_ipv6only;
1219	break;
1220
1221	case IPV6_RECVPKTINFO:
1222	val = np->rxopt.bits.rxinfo;
1223	break;
1224
1225	case IPV6_2292PKTINFO:
1226	val = np->rxopt.bits.rxoinfo;
1227	break;
1228
1229	case IPV6_RECVHOPLIMIT:
1230	val = np->rxopt.bits.rxhlim;
1231	break;
1232
1233	case IPV6_2292HOPLIMIT:
1234	val = np->rxopt.bits.rxohlim;
1235	break;
1236
1237	case IPV6_RECVRTHDR:
1238	val = np->rxopt.bits.srcrt;
1239	break;
1240
1241	case IPV6_2292RTHDR:
1242	val = np->rxopt.bits.osrcrt;
1243	break;
1244
1245	case IPV6_HOPOPTS:
1246	case IPV6_RTHDRDSTOPTS:
1247	case IPV6_RTHDR:
1248	case IPV6_DSTOPTS:
1249	{
1250	struct ipv6_txoptions *opt;
1251
1252	sockopt_lock_sock(sk);
1253	opt = rcu_dereference_protected(np->opt,
1254	lockdep_sock_is_held(sk));
1255	len = ipv6_getsockopt_sticky(sk, opt, optname, optval, len);
1256	sockopt_release_sock(sk);
1257	/* check if ipv6_getsockopt_sticky() returns err code */
1258	if (len < 0)
1259	return len;
1260	return copy_to_sockptr(dst: optlen, src: &len, size: sizeof(int));
1261	}
1262
1263	case IPV6_RECVHOPOPTS:
1264	val = np->rxopt.bits.hopopts;
1265	break;
1266
1267	case IPV6_2292HOPOPTS:
1268	val = np->rxopt.bits.ohopopts;
1269	break;
1270
1271	case IPV6_RECVDSTOPTS:
1272	val = np->rxopt.bits.dstopts;
1273	break;
1274
1275	case IPV6_2292DSTOPTS:
1276	val = np->rxopt.bits.odstopts;
1277	break;
1278
1279	case IPV6_TCLASS:
1280	val = np->tclass;
1281	break;
1282
1283	case IPV6_RECVTCLASS:
1284	val = np->rxopt.bits.rxtclass;
1285	break;
1286
1287	case IPV6_FLOWINFO:
1288	val = np->rxopt.bits.rxflow;
1289	break;
1290
1291	case IPV6_RECVPATHMTU:
1292	val = np->rxopt.bits.rxpmtu;
1293	break;
1294
1295	case IPV6_PATHMTU:
1296	{
1297	struct dst_entry *dst;
1298	struct ip6_mtuinfo mtuinfo;
1299
1300	if (len < sizeof(mtuinfo))
1301	return -EINVAL;
1302
1303	len = sizeof(mtuinfo);
1304	memset(&mtuinfo, 0, sizeof(mtuinfo));
1305
1306	rcu_read_lock();
1307	dst = __sk_dst_get(sk);
1308	if (dst)
1309	mtuinfo.ip6m_mtu = dst_mtu(dst);
1310	rcu_read_unlock();
1311	if (!mtuinfo.ip6m_mtu)
1312	return -ENOTCONN;
1313
1314	if (copy_to_sockptr(dst: optlen, src: &len, size: sizeof(int)))
1315	return -EFAULT;
1316	if (copy_to_sockptr(dst: optval, src: &mtuinfo, size: len))
1317	return -EFAULT;
1318
1319	return 0;
1320	}
1321
1322	case IPV6_TRANSPARENT:
1323	val = inet_test_bit(TRANSPARENT, sk);
1324	break;
1325
1326	case IPV6_FREEBIND:
1327	val = inet_test_bit(FREEBIND, sk);
1328	break;
1329
1330	case IPV6_RECVORIGDSTADDR:
1331	val = np->rxopt.bits.rxorigdstaddr;
1332	break;
1333
1334	case IPV6_UNICAST_HOPS:
1335	case IPV6_MULTICAST_HOPS:
1336	{
1337	struct dst_entry *dst;
1338
1339	if (optname == IPV6_UNICAST_HOPS)
1340	val = READ_ONCE(np->hop_limit);
1341	else
1342	val = READ_ONCE(np->mcast_hops);
1343
1344	if (val < 0) {
1345	rcu_read_lock();
1346	dst = __sk_dst_get(sk);
1347	if (dst)
1348	val = ip6_dst_hoplimit(dst);
1349	rcu_read_unlock();
1350	}
1351
1352	if (val < 0)
1353	val = sock_net(sk)->ipv6.devconf_all->hop_limit;
1354	break;
1355	}
1356
1357	case IPV6_MULTICAST_LOOP:
1358	val = inet6_test_bit(MC6_LOOP, sk);
1359	break;
1360
1361	case IPV6_MULTICAST_IF:
1362	val = np->mcast_oif;
1363	break;
1364
1365	case IPV6_MULTICAST_ALL:
1366	val = inet6_test_bit(MC6_ALL, sk);
1367	break;
1368
1369	case IPV6_UNICAST_IF:
1370	val = (__force int)htonl((__u32) np->ucast_oif);
1371	break;
1372
1373	case IPV6_MTU_DISCOVER:
1374	val = READ_ONCE(np->pmtudisc);
1375	break;
1376
1377	case IPV6_RECVERR:
1378	val = inet6_test_bit(RECVERR6, sk);
1379	break;
1380
1381	case IPV6_FLOWINFO_SEND:
1382	val = inet6_test_bit(SNDFLOW, sk);
1383	break;
1384
1385	case IPV6_FLOWLABEL_MGR:
1386	{
1387	struct in6_flowlabel_req freq;
1388	int flags;
1389
1390	if (len < sizeof(freq))
1391	return -EINVAL;
1392
1393	if (copy_from_sockptr(dst: &freq, src: optval, size: sizeof(freq)))
1394	return -EFAULT;
1395
1396	if (freq.flr_action != IPV6_FL_A_GET)
1397	return -EINVAL;
1398
1399	len = sizeof(freq);
1400	flags = freq.flr_flags;
1401
1402	memset(&freq, 0, sizeof(freq));
1403
1404	val = ipv6_flowlabel_opt_get(sk, freq: &freq, flags);
1405	if (val < 0)
1406	return val;
1407
1408	if (copy_to_sockptr(dst: optlen, src: &len, size: sizeof(int)))
1409	return -EFAULT;
1410	if (copy_to_sockptr(dst: optval, src: &freq, size: len))
1411	return -EFAULT;
1412
1413	return 0;
1414	}
1415
1416	case IPV6_ADDR_PREFERENCES:
1417	{
1418	u8 srcprefs = READ_ONCE(np->srcprefs);
1419	val = 0;
1420
1421	if (srcprefs & IPV6_PREFER_SRC_TMP)
1422	val |= IPV6_PREFER_SRC_TMP;
1423	else if (srcprefs & IPV6_PREFER_SRC_PUBLIC)
1424	val |= IPV6_PREFER_SRC_PUBLIC;
1425	else {
1426	/* XXX: should we return system default? */
1427	val |= IPV6_PREFER_SRC_PUBTMP_DEFAULT;
1428	}
1429
1430	if (srcprefs & IPV6_PREFER_SRC_COA)
1431	val |= IPV6_PREFER_SRC_COA;
1432	else
1433	val |= IPV6_PREFER_SRC_HOME;
1434	break;
1435	}
1436	case IPV6_MINHOPCOUNT:
1437	val = READ_ONCE(np->min_hopcount);
1438	break;
1439
1440	case IPV6_DONTFRAG:
1441	val = inet6_test_bit(DONTFRAG, sk);
1442	break;
1443
1444	case IPV6_AUTOFLOWLABEL:
1445	val = ip6_autoflowlabel(net: sock_net(sk), sk);
1446	break;
1447
1448	case IPV6_RECVFRAGSIZE:
1449	val = np->rxopt.bits.recvfragsize;
1450	break;
1451
1452	case IPV6_ROUTER_ALERT_ISOLATE:
1453	val = inet6_test_bit(RTALERT_ISOLATE, sk);
1454	break;
1455
1456	case IPV6_RECVERR_RFC4884:
1457	val = inet6_test_bit(RECVERR6_RFC4884, sk);
1458	break;
1459
1460	default:
1461	return -ENOPROTOOPT;
1462	}
1463	len = min_t(unsigned int, sizeof(int), len);
1464	if (copy_to_sockptr(dst: optlen, src: &len, size: sizeof(int)))
1465	return -EFAULT;
1466	if (copy_to_sockptr(dst: optval, src: &val, size: len))
1467	return -EFAULT;
1468	return 0;
1469	}
1470
1471	int ipv6_getsockopt(struct sock *sk, int level, int optname,
1472	char __user *optval, int __user *optlen)
1473	{
1474	int err;
1475
1476	if (level == SOL_IP && sk->sk_type != SOCK_RAW)
1477	return udp_prot.getsockopt(sk, level, optname, optval, optlen);
1478
1479	if (level != SOL_IPV6)
1480	return -ENOPROTOOPT;
1481
1482	err = do_ipv6_getsockopt(sk, level, optname,
1483	optval: USER_SOCKPTR(p: optval), optlen: USER_SOCKPTR(p: optlen));
1484	#ifdef CONFIG_NETFILTER
1485	/* we need to exclude all possible ENOPROTOOPTs except default case */
1486	if (err == -ENOPROTOOPT && optname != IPV6_2292PKTOPTIONS) {
1487	int len;
1488
1489	if (get_user(len, optlen))
1490	return -EFAULT;
1491
1492	err = nf_getsockopt(sk, PF_INET6, optval: optname, opt: optval, len: &len);
1493	if (err >= 0)
1494	err = put_user(len, optlen);
1495	}
1496	#endif
1497	return err;
1498	}
1499	EXPORT_SYMBOL(ipv6_getsockopt);
1500