net: Fix data-races around sysctl_optmem_max.
[sfrench/cifs-2.6.git] / net / ipv6 / ipv6_sockglue.c
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_sk(sk)->is_icsk) {
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 && !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 static 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         if (needs_rtnl)
419                 rtnl_lock();
420         lock_sock(sk);
421
422         switch (optname) {
423
424         case IPV6_ADDRFORM:
425                 if (optlen < sizeof(int))
426                         goto e_inval;
427                 if (val == PF_INET) {
428                         struct ipv6_txoptions *opt;
429                         struct sk_buff *pktopt;
430
431                         if (sk->sk_type == SOCK_RAW)
432                                 break;
433
434                         if (sk->sk_protocol == IPPROTO_UDP ||
435                             sk->sk_protocol == IPPROTO_UDPLITE) {
436                                 struct udp_sock *up = udp_sk(sk);
437                                 if (up->pending == AF_INET6) {
438                                         retv = -EBUSY;
439                                         break;
440                                 }
441                         } else if (sk->sk_protocol == IPPROTO_TCP) {
442                                 if (sk->sk_prot != &tcpv6_prot) {
443                                         retv = -EBUSY;
444                                         break;
445                                 }
446                         } else {
447                                 break;
448                         }
449
450                         if (sk->sk_state != TCP_ESTABLISHED) {
451                                 retv = -ENOTCONN;
452                                 break;
453                         }
454
455                         if (ipv6_only_sock(sk) ||
456                             !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) {
457                                 retv = -EADDRNOTAVAIL;
458                                 break;
459                         }
460
461                         fl6_free_socklist(sk);
462                         __ipv6_sock_mc_close(sk);
463                         __ipv6_sock_ac_close(sk);
464
465                         /*
466                          * Sock is moving from IPv6 to IPv4 (sk_prot), so
467                          * remove it from the refcnt debug socks count in the
468                          * original family...
469                          */
470                         sk_refcnt_debug_dec(sk);
471
472                         if (sk->sk_protocol == IPPROTO_TCP) {
473                                 struct inet_connection_sock *icsk = inet_csk(sk);
474
475                                 sock_prot_inuse_add(net, sk->sk_prot, -1);
476                                 sock_prot_inuse_add(net, &tcp_prot, 1);
477
478                                 /* Paired with READ_ONCE(sk->sk_prot) in net/ipv6/af_inet6.c */
479                                 WRITE_ONCE(sk->sk_prot, &tcp_prot);
480                                 icsk->icsk_af_ops = &ipv4_specific;
481                                 sk->sk_socket->ops = &inet_stream_ops;
482                                 sk->sk_family = PF_INET;
483                                 tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
484                         } else {
485                                 struct proto *prot = &udp_prot;
486
487                                 if (sk->sk_protocol == IPPROTO_UDPLITE)
488                                         prot = &udplite_prot;
489
490                                 sock_prot_inuse_add(net, sk->sk_prot, -1);
491                                 sock_prot_inuse_add(net, prot, 1);
492
493                                 /* Paired with READ_ONCE(sk->sk_prot) in net/ipv6/af_inet6.c */
494                                 WRITE_ONCE(sk->sk_prot, prot);
495                                 sk->sk_socket->ops = &inet_dgram_ops;
496                                 sk->sk_family = PF_INET;
497                         }
498                         opt = xchg((__force struct ipv6_txoptions **)&np->opt,
499                                    NULL);
500                         if (opt) {
501                                 atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
502                                 txopt_put(opt);
503                         }
504                         pktopt = xchg(&np->pktoptions, NULL);
505                         kfree_skb(pktopt);
506
507                         /*
508                          * ... and add it to the refcnt debug socks count
509                          * in the new family. -acme
510                          */
511                         sk_refcnt_debug_inc(sk);
512                         module_put(THIS_MODULE);
513                         retv = 0;
514                         break;
515                 }
516                 goto e_inval;
517
518         case IPV6_V6ONLY:
519                 if (optlen < sizeof(int) ||
520                     inet_sk(sk)->inet_num)
521                         goto e_inval;
522                 sk->sk_ipv6only = valbool;
523                 retv = 0;
524                 break;
525
526         case IPV6_RECVPKTINFO:
527                 if (optlen < sizeof(int))
528                         goto e_inval;
529                 np->rxopt.bits.rxinfo = valbool;
530                 retv = 0;
531                 break;
532
533         case IPV6_2292PKTINFO:
534                 if (optlen < sizeof(int))
535                         goto e_inval;
536                 np->rxopt.bits.rxoinfo = valbool;
537                 retv = 0;
538                 break;
539
540         case IPV6_RECVHOPLIMIT:
541                 if (optlen < sizeof(int))
542                         goto e_inval;
543                 np->rxopt.bits.rxhlim = valbool;
544                 retv = 0;
545                 break;
546
547         case IPV6_2292HOPLIMIT:
548                 if (optlen < sizeof(int))
549                         goto e_inval;
550                 np->rxopt.bits.rxohlim = valbool;
551                 retv = 0;
552                 break;
553
554         case IPV6_RECVRTHDR:
555                 if (optlen < sizeof(int))
556                         goto e_inval;
557                 np->rxopt.bits.srcrt = valbool;
558                 retv = 0;
559                 break;
560
561         case IPV6_2292RTHDR:
562                 if (optlen < sizeof(int))
563                         goto e_inval;
564                 np->rxopt.bits.osrcrt = valbool;
565                 retv = 0;
566                 break;
567
568         case IPV6_RECVHOPOPTS:
569                 if (optlen < sizeof(int))
570                         goto e_inval;
571                 np->rxopt.bits.hopopts = valbool;
572                 retv = 0;
573                 break;
574
575         case IPV6_2292HOPOPTS:
576                 if (optlen < sizeof(int))
577                         goto e_inval;
578                 np->rxopt.bits.ohopopts = valbool;
579                 retv = 0;
580                 break;
581
582         case IPV6_RECVDSTOPTS:
583                 if (optlen < sizeof(int))
584                         goto e_inval;
585                 np->rxopt.bits.dstopts = valbool;
586                 retv = 0;
587                 break;
588
589         case IPV6_2292DSTOPTS:
590                 if (optlen < sizeof(int))
591                         goto e_inval;
592                 np->rxopt.bits.odstopts = valbool;
593                 retv = 0;
594                 break;
595
596         case IPV6_TCLASS:
597                 if (optlen < sizeof(int))
598                         goto e_inval;
599                 if (val < -1 || val > 0xff)
600                         goto e_inval;
601                 /* RFC 3542, 6.5: default traffic class of 0x0 */
602                 if (val == -1)
603                         val = 0;
604                 if (sk->sk_type == SOCK_STREAM) {
605                         val &= ~INET_ECN_MASK;
606                         val |= np->tclass & INET_ECN_MASK;
607                 }
608                 if (np->tclass != val) {
609                         np->tclass = val;
610                         sk_dst_reset(sk);
611                 }
612                 retv = 0;
613                 break;
614
615         case IPV6_RECVTCLASS:
616                 if (optlen < sizeof(int))
617                         goto e_inval;
618                 np->rxopt.bits.rxtclass = valbool;
619                 retv = 0;
620                 break;
621
622         case IPV6_FLOWINFO:
623                 if (optlen < sizeof(int))
624                         goto e_inval;
625                 np->rxopt.bits.rxflow = valbool;
626                 retv = 0;
627                 break;
628
629         case IPV6_RECVPATHMTU:
630                 if (optlen < sizeof(int))
631                         goto e_inval;
632                 np->rxopt.bits.rxpmtu = valbool;
633                 retv = 0;
634                 break;
635
636         case IPV6_TRANSPARENT:
637                 if (valbool && !ns_capable(net->user_ns, CAP_NET_RAW) &&
638                     !ns_capable(net->user_ns, CAP_NET_ADMIN)) {
639                         retv = -EPERM;
640                         break;
641                 }
642                 if (optlen < sizeof(int))
643                         goto e_inval;
644                 /* we don't have a separate transparent bit for IPV6 we use the one in the IPv4 socket */
645                 inet_sk(sk)->transparent = valbool;
646                 retv = 0;
647                 break;
648
649         case IPV6_FREEBIND:
650                 if (optlen < sizeof(int))
651                         goto e_inval;
652                 /* we also don't have a separate freebind bit for IPV6 */
653                 inet_sk(sk)->freebind = valbool;
654                 retv = 0;
655                 break;
656
657         case IPV6_RECVORIGDSTADDR:
658                 if (optlen < sizeof(int))
659                         goto e_inval;
660                 np->rxopt.bits.rxorigdstaddr = valbool;
661                 retv = 0;
662                 break;
663
664         case IPV6_HOPOPTS:
665         case IPV6_RTHDRDSTOPTS:
666         case IPV6_RTHDR:
667         case IPV6_DSTOPTS:
668                 retv = ipv6_set_opt_hdr(sk, optname, optval, optlen);
669                 break;
670
671         case IPV6_PKTINFO:
672         {
673                 struct in6_pktinfo pkt;
674
675                 if (optlen == 0)
676                         goto e_inval;
677                 else if (optlen < sizeof(struct in6_pktinfo) ||
678                          sockptr_is_null(optval))
679                         goto e_inval;
680
681                 if (copy_from_sockptr(&pkt, optval, sizeof(pkt))) {
682                         retv = -EFAULT;
683                         break;
684                 }
685                 if (!sk_dev_equal_l3scope(sk, pkt.ipi6_ifindex))
686                         goto e_inval;
687
688                 np->sticky_pktinfo.ipi6_ifindex = pkt.ipi6_ifindex;
689                 np->sticky_pktinfo.ipi6_addr = pkt.ipi6_addr;
690                 retv = 0;
691                 break;
692         }
693
694         case IPV6_2292PKTOPTIONS:
695         {
696                 struct ipv6_txoptions *opt = NULL;
697                 struct msghdr msg;
698                 struct flowi6 fl6;
699                 struct ipcm6_cookie ipc6;
700
701                 memset(&fl6, 0, sizeof(fl6));
702                 fl6.flowi6_oif = sk->sk_bound_dev_if;
703                 fl6.flowi6_mark = sk->sk_mark;
704
705                 if (optlen == 0)
706                         goto update;
707
708                 /* 1K is probably excessive
709                  * 1K is surely not enough, 2K per standard header is 16K.
710                  */
711                 retv = -EINVAL;
712                 if (optlen > 64*1024)
713                         break;
714
715                 opt = sock_kmalloc(sk, sizeof(*opt) + optlen, GFP_KERNEL);
716                 retv = -ENOBUFS;
717                 if (!opt)
718                         break;
719
720                 memset(opt, 0, sizeof(*opt));
721                 refcount_set(&opt->refcnt, 1);
722                 opt->tot_len = sizeof(*opt) + optlen;
723                 retv = -EFAULT;
724                 if (copy_from_sockptr(opt + 1, optval, optlen))
725                         goto done;
726
727                 msg.msg_controllen = optlen;
728                 msg.msg_control = (void *)(opt+1);
729                 ipc6.opt = opt;
730
731                 retv = ip6_datagram_send_ctl(net, sk, &msg, &fl6, &ipc6);
732                 if (retv)
733                         goto done;
734 update:
735                 retv = 0;
736                 opt = ipv6_update_options(sk, opt);
737 done:
738                 if (opt) {
739                         atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
740                         txopt_put(opt);
741                 }
742                 break;
743         }
744         case IPV6_UNICAST_HOPS:
745                 if (optlen < sizeof(int))
746                         goto e_inval;
747                 if (val > 255 || val < -1)
748                         goto e_inval;
749                 np->hop_limit = val;
750                 retv = 0;
751                 break;
752
753         case IPV6_MULTICAST_HOPS:
754                 if (sk->sk_type == SOCK_STREAM)
755                         break;
756                 if (optlen < sizeof(int))
757                         goto e_inval;
758                 if (val > 255 || val < -1)
759                         goto e_inval;
760                 np->mcast_hops = (val == -1 ? IPV6_DEFAULT_MCASTHOPS : val);
761                 retv = 0;
762                 break;
763
764         case IPV6_MULTICAST_LOOP:
765                 if (optlen < sizeof(int))
766                         goto e_inval;
767                 if (val != valbool)
768                         goto e_inval;
769                 np->mc_loop = valbool;
770                 retv = 0;
771                 break;
772
773         case IPV6_UNICAST_IF:
774         {
775                 struct net_device *dev = NULL;
776                 int ifindex;
777
778                 if (optlen != sizeof(int))
779                         goto e_inval;
780
781                 ifindex = (__force int)ntohl((__force __be32)val);
782                 if (ifindex == 0) {
783                         np->ucast_oif = 0;
784                         retv = 0;
785                         break;
786                 }
787
788                 dev = dev_get_by_index(net, ifindex);
789                 retv = -EADDRNOTAVAIL;
790                 if (!dev)
791                         break;
792                 dev_put(dev);
793
794                 retv = -EINVAL;
795                 if (sk->sk_bound_dev_if)
796                         break;
797
798                 np->ucast_oif = ifindex;
799                 retv = 0;
800                 break;
801         }
802
803         case IPV6_MULTICAST_IF:
804                 if (sk->sk_type == SOCK_STREAM)
805                         break;
806                 if (optlen < sizeof(int))
807                         goto e_inval;
808
809                 if (val) {
810                         struct net_device *dev;
811                         int midx;
812
813                         rcu_read_lock();
814
815                         dev = dev_get_by_index_rcu(net, val);
816                         if (!dev) {
817                                 rcu_read_unlock();
818                                 retv = -ENODEV;
819                                 break;
820                         }
821                         midx = l3mdev_master_ifindex_rcu(dev);
822
823                         rcu_read_unlock();
824
825                         if (sk->sk_bound_dev_if &&
826                             sk->sk_bound_dev_if != val &&
827                             (!midx || midx != sk->sk_bound_dev_if))
828                                 goto e_inval;
829                 }
830                 np->mcast_oif = val;
831                 retv = 0;
832                 break;
833         case IPV6_ADD_MEMBERSHIP:
834         case IPV6_DROP_MEMBERSHIP:
835         {
836                 struct ipv6_mreq mreq;
837
838                 if (optlen < sizeof(struct ipv6_mreq))
839                         goto e_inval;
840
841                 retv = -EPROTO;
842                 if (inet_sk(sk)->is_icsk)
843                         break;
844
845                 retv = -EFAULT;
846                 if (copy_from_sockptr(&mreq, optval, sizeof(struct ipv6_mreq)))
847                         break;
848
849                 if (optname == IPV6_ADD_MEMBERSHIP)
850                         retv = ipv6_sock_mc_join(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr);
851                 else
852                         retv = ipv6_sock_mc_drop(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr);
853                 break;
854         }
855         case IPV6_JOIN_ANYCAST:
856         case IPV6_LEAVE_ANYCAST:
857         {
858                 struct ipv6_mreq mreq;
859
860                 if (optlen < sizeof(struct ipv6_mreq))
861                         goto e_inval;
862
863                 retv = -EFAULT;
864                 if (copy_from_sockptr(&mreq, optval, sizeof(struct ipv6_mreq)))
865                         break;
866
867                 if (optname == IPV6_JOIN_ANYCAST)
868                         retv = ipv6_sock_ac_join(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_acaddr);
869                 else
870                         retv = ipv6_sock_ac_drop(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_acaddr);
871                 break;
872         }
873         case IPV6_MULTICAST_ALL:
874                 if (optlen < sizeof(int))
875                         goto e_inval;
876                 np->mc_all = valbool;
877                 retv = 0;
878                 break;
879
880         case MCAST_JOIN_GROUP:
881         case MCAST_LEAVE_GROUP:
882                 if (in_compat_syscall())
883                         retv = compat_ipv6_mcast_join_leave(sk, optname, optval,
884                                                             optlen);
885                 else
886                         retv = ipv6_mcast_join_leave(sk, optname, optval,
887                                                      optlen);
888                 break;
889         case MCAST_JOIN_SOURCE_GROUP:
890         case MCAST_LEAVE_SOURCE_GROUP:
891         case MCAST_BLOCK_SOURCE:
892         case MCAST_UNBLOCK_SOURCE:
893                 retv = do_ipv6_mcast_group_source(sk, optname, optval, optlen);
894                 break;
895         case MCAST_MSFILTER:
896                 if (in_compat_syscall())
897                         retv = compat_ipv6_set_mcast_msfilter(sk, optval,
898                                                               optlen);
899                 else
900                         retv = ipv6_set_mcast_msfilter(sk, optval, optlen);
901                 break;
902         case IPV6_ROUTER_ALERT:
903                 if (optlen < sizeof(int))
904                         goto e_inval;
905                 retv = ip6_ra_control(sk, val);
906                 break;
907         case IPV6_ROUTER_ALERT_ISOLATE:
908                 if (optlen < sizeof(int))
909                         goto e_inval;
910                 np->rtalert_isolate = valbool;
911                 retv = 0;
912                 break;
913         case IPV6_MTU_DISCOVER:
914                 if (optlen < sizeof(int))
915                         goto e_inval;
916                 if (val < IPV6_PMTUDISC_DONT || val > IPV6_PMTUDISC_OMIT)
917                         goto e_inval;
918                 np->pmtudisc = val;
919                 retv = 0;
920                 break;
921         case IPV6_MTU:
922                 if (optlen < sizeof(int))
923                         goto e_inval;
924                 if (val && val < IPV6_MIN_MTU)
925                         goto e_inval;
926                 np->frag_size = val;
927                 retv = 0;
928                 break;
929         case IPV6_RECVERR:
930                 if (optlen < sizeof(int))
931                         goto e_inval;
932                 np->recverr = valbool;
933                 if (!val)
934                         skb_queue_purge(&sk->sk_error_queue);
935                 retv = 0;
936                 break;
937         case IPV6_FLOWINFO_SEND:
938                 if (optlen < sizeof(int))
939                         goto e_inval;
940                 np->sndflow = valbool;
941                 retv = 0;
942                 break;
943         case IPV6_FLOWLABEL_MGR:
944                 retv = ipv6_flowlabel_opt(sk, optval, optlen);
945                 break;
946         case IPV6_IPSEC_POLICY:
947         case IPV6_XFRM_POLICY:
948                 retv = -EPERM;
949                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
950                         break;
951                 retv = xfrm_user_policy(sk, optname, optval, optlen);
952                 break;
953
954         case IPV6_ADDR_PREFERENCES:
955                 if (optlen < sizeof(int))
956                         goto e_inval;
957                 retv = __ip6_sock_set_addr_preferences(sk, val);
958                 break;
959         case IPV6_MINHOPCOUNT:
960                 if (optlen < sizeof(int))
961                         goto e_inval;
962                 if (val < 0 || val > 255)
963                         goto e_inval;
964
965                 if (val)
966                         static_branch_enable(&ip6_min_hopcount);
967
968                 /* tcp_v6_err() and tcp_v6_rcv() might read min_hopcount
969                  * while we are changing it.
970                  */
971                 WRITE_ONCE(np->min_hopcount, val);
972                 retv = 0;
973                 break;
974         case IPV6_DONTFRAG:
975                 np->dontfrag = valbool;
976                 retv = 0;
977                 break;
978         case IPV6_AUTOFLOWLABEL:
979                 np->autoflowlabel = valbool;
980                 np->autoflowlabel_set = 1;
981                 retv = 0;
982                 break;
983         case IPV6_RECVFRAGSIZE:
984                 np->rxopt.bits.recvfragsize = valbool;
985                 retv = 0;
986                 break;
987         case IPV6_RECVERR_RFC4884:
988                 if (optlen < sizeof(int))
989                         goto e_inval;
990                 if (val < 0 || val > 1)
991                         goto e_inval;
992                 np->recverr_rfc4884 = valbool;
993                 retv = 0;
994                 break;
995         }
996
997         release_sock(sk);
998         if (needs_rtnl)
999                 rtnl_unlock();
1000
1001         return retv;
1002
1003 e_inval:
1004         release_sock(sk);
1005         if (needs_rtnl)
1006                 rtnl_unlock();
1007         return -EINVAL;
1008 }
1009
1010 int ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
1011                     unsigned int optlen)
1012 {
1013         int err;
1014
1015         if (level == SOL_IP && sk->sk_type != SOCK_RAW)
1016                 return udp_prot.setsockopt(sk, level, optname, optval, optlen);
1017
1018         if (level != SOL_IPV6)
1019                 return -ENOPROTOOPT;
1020
1021         err = do_ipv6_setsockopt(sk, level, optname, optval, optlen);
1022 #ifdef CONFIG_NETFILTER
1023         /* we need to exclude all possible ENOPROTOOPTs except default case */
1024         if (err == -ENOPROTOOPT && optname != IPV6_IPSEC_POLICY &&
1025                         optname != IPV6_XFRM_POLICY)
1026                 err = nf_setsockopt(sk, PF_INET6, optname, optval, optlen);
1027 #endif
1028         return err;
1029 }
1030 EXPORT_SYMBOL(ipv6_setsockopt);
1031
1032 static int ipv6_getsockopt_sticky(struct sock *sk, struct ipv6_txoptions *opt,
1033                                   int optname, char __user *optval, int len)
1034 {
1035         struct ipv6_opt_hdr *hdr;
1036
1037         if (!opt)
1038                 return 0;
1039
1040         switch (optname) {
1041         case IPV6_HOPOPTS:
1042                 hdr = opt->hopopt;
1043                 break;
1044         case IPV6_RTHDRDSTOPTS:
1045                 hdr = opt->dst0opt;
1046                 break;
1047         case IPV6_RTHDR:
1048                 hdr = (struct ipv6_opt_hdr *)opt->srcrt;
1049                 break;
1050         case IPV6_DSTOPTS:
1051                 hdr = opt->dst1opt;
1052                 break;
1053         default:
1054                 return -EINVAL; /* should not happen */
1055         }
1056
1057         if (!hdr)
1058                 return 0;
1059
1060         len = min_t(unsigned int, len, ipv6_optlen(hdr));
1061         if (copy_to_user(optval, hdr, len))
1062                 return -EFAULT;
1063         return len;
1064 }
1065
1066 static int ipv6_get_msfilter(struct sock *sk, void __user *optval,
1067                 int __user *optlen, int len)
1068 {
1069         const int size0 = offsetof(struct group_filter, gf_slist_flex);
1070         struct group_filter __user *p = optval;
1071         struct group_filter gsf;
1072         int num;
1073         int err;
1074
1075         if (len < size0)
1076                 return -EINVAL;
1077         if (copy_from_user(&gsf, p, size0))
1078                 return -EFAULT;
1079         if (gsf.gf_group.ss_family != AF_INET6)
1080                 return -EADDRNOTAVAIL;
1081         num = gsf.gf_numsrc;
1082         lock_sock(sk);
1083         err = ip6_mc_msfget(sk, &gsf, p->gf_slist_flex);
1084         if (!err) {
1085                 if (num > gsf.gf_numsrc)
1086                         num = gsf.gf_numsrc;
1087                 if (put_user(GROUP_FILTER_SIZE(num), optlen) ||
1088                     copy_to_user(p, &gsf, size0))
1089                         err = -EFAULT;
1090         }
1091         release_sock(sk);
1092         return err;
1093 }
1094
1095 static int compat_ipv6_get_msfilter(struct sock *sk, void __user *optval,
1096                 int __user *optlen)
1097 {
1098         const int size0 = offsetof(struct compat_group_filter, gf_slist_flex);
1099         struct compat_group_filter __user *p = optval;
1100         struct compat_group_filter gf32;
1101         struct group_filter gf;
1102         int len, err;
1103         int num;
1104
1105         if (get_user(len, optlen))
1106                 return -EFAULT;
1107         if (len < size0)
1108                 return -EINVAL;
1109
1110         if (copy_from_user(&gf32, p, size0))
1111                 return -EFAULT;
1112         gf.gf_interface = gf32.gf_interface;
1113         gf.gf_fmode = gf32.gf_fmode;
1114         num = gf.gf_numsrc = gf32.gf_numsrc;
1115         gf.gf_group = gf32.gf_group;
1116
1117         if (gf.gf_group.ss_family != AF_INET6)
1118                 return -EADDRNOTAVAIL;
1119
1120         lock_sock(sk);
1121         err = ip6_mc_msfget(sk, &gf, p->gf_slist_flex);
1122         release_sock(sk);
1123         if (err)
1124                 return err;
1125         if (num > gf.gf_numsrc)
1126                 num = gf.gf_numsrc;
1127         len = GROUP_FILTER_SIZE(num) - (sizeof(gf)-sizeof(gf32));
1128         if (put_user(len, optlen) ||
1129             put_user(gf.gf_fmode, &p->gf_fmode) ||
1130             put_user(gf.gf_numsrc, &p->gf_numsrc))
1131                 return -EFAULT;
1132         return 0;
1133 }
1134
1135 static int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
1136                     char __user *optval, int __user *optlen, unsigned int flags)
1137 {
1138         struct ipv6_pinfo *np = inet6_sk(sk);
1139         int len;
1140         int val;
1141
1142         if (ip6_mroute_opt(optname))
1143                 return ip6_mroute_getsockopt(sk, optname, optval, optlen);
1144
1145         if (get_user(len, optlen))
1146                 return -EFAULT;
1147         switch (optname) {
1148         case IPV6_ADDRFORM:
1149                 if (sk->sk_protocol != IPPROTO_UDP &&
1150                     sk->sk_protocol != IPPROTO_UDPLITE &&
1151                     sk->sk_protocol != IPPROTO_TCP)
1152                         return -ENOPROTOOPT;
1153                 if (sk->sk_state != TCP_ESTABLISHED)
1154                         return -ENOTCONN;
1155                 val = sk->sk_family;
1156                 break;
1157         case MCAST_MSFILTER:
1158                 if (in_compat_syscall())
1159                         return compat_ipv6_get_msfilter(sk, optval, optlen);
1160                 return ipv6_get_msfilter(sk, optval, optlen, len);
1161         case IPV6_2292PKTOPTIONS:
1162         {
1163                 struct msghdr msg;
1164                 struct sk_buff *skb;
1165
1166                 if (sk->sk_type != SOCK_STREAM)
1167                         return -ENOPROTOOPT;
1168
1169                 msg.msg_control_user = optval;
1170                 msg.msg_controllen = len;
1171                 msg.msg_flags = flags;
1172                 msg.msg_control_is_user = true;
1173
1174                 lock_sock(sk);
1175                 skb = np->pktoptions;
1176                 if (skb)
1177                         ip6_datagram_recv_ctl(sk, &msg, skb);
1178                 release_sock(sk);
1179                 if (!skb) {
1180                         if (np->rxopt.bits.rxinfo) {
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 : np->sticky_pktinfo.ipi6_addr;
1185                                 put_cmsg(&msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
1186                         }
1187                         if (np->rxopt.bits.rxhlim) {
1188                                 int hlim = np->mcast_hops;
1189                                 put_cmsg(&msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
1190                         }
1191                         if (np->rxopt.bits.rxtclass) {
1192                                 int tclass = (int)ip6_tclass(np->rcv_flowinfo);
1193
1194                                 put_cmsg(&msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
1195                         }
1196                         if (np->rxopt.bits.rxoinfo) {
1197                                 struct in6_pktinfo src_info;
1198                                 src_info.ipi6_ifindex = np->mcast_oif ? np->mcast_oif :
1199                                         np->sticky_pktinfo.ipi6_ifindex;
1200                                 src_info.ipi6_addr = np->mcast_oif ? sk->sk_v6_daddr :
1201                                                                      np->sticky_pktinfo.ipi6_addr;
1202                                 put_cmsg(&msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
1203                         }
1204                         if (np->rxopt.bits.rxohlim) {
1205                                 int hlim = np->mcast_hops;
1206                                 put_cmsg(&msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
1207                         }
1208                         if (np->rxopt.bits.rxflow) {
1209                                 __be32 flowinfo = np->rcv_flowinfo;
1210
1211                                 put_cmsg(&msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
1212                         }
1213                 }
1214                 len -= msg.msg_controllen;
1215                 return put_user(len, optlen);
1216         }
1217         case IPV6_MTU:
1218         {
1219                 struct dst_entry *dst;
1220
1221                 val = 0;
1222                 rcu_read_lock();
1223                 dst = __sk_dst_get(sk);
1224                 if (dst)
1225                         val = dst_mtu(dst);
1226                 rcu_read_unlock();
1227                 if (!val)
1228                         return -ENOTCONN;
1229                 break;
1230         }
1231
1232         case IPV6_V6ONLY:
1233                 val = sk->sk_ipv6only;
1234                 break;
1235
1236         case IPV6_RECVPKTINFO:
1237                 val = np->rxopt.bits.rxinfo;
1238                 break;
1239
1240         case IPV6_2292PKTINFO:
1241                 val = np->rxopt.bits.rxoinfo;
1242                 break;
1243
1244         case IPV6_RECVHOPLIMIT:
1245                 val = np->rxopt.bits.rxhlim;
1246                 break;
1247
1248         case IPV6_2292HOPLIMIT:
1249                 val = np->rxopt.bits.rxohlim;
1250                 break;
1251
1252         case IPV6_RECVRTHDR:
1253                 val = np->rxopt.bits.srcrt;
1254                 break;
1255
1256         case IPV6_2292RTHDR:
1257                 val = np->rxopt.bits.osrcrt;
1258                 break;
1259
1260         case IPV6_HOPOPTS:
1261         case IPV6_RTHDRDSTOPTS:
1262         case IPV6_RTHDR:
1263         case IPV6_DSTOPTS:
1264         {
1265                 struct ipv6_txoptions *opt;
1266
1267                 lock_sock(sk);
1268                 opt = rcu_dereference_protected(np->opt,
1269                                                 lockdep_sock_is_held(sk));
1270                 len = ipv6_getsockopt_sticky(sk, opt, optname, optval, len);
1271                 release_sock(sk);
1272                 /* check if ipv6_getsockopt_sticky() returns err code */
1273                 if (len < 0)
1274                         return len;
1275                 return put_user(len, optlen);
1276         }
1277
1278         case IPV6_RECVHOPOPTS:
1279                 val = np->rxopt.bits.hopopts;
1280                 break;
1281
1282         case IPV6_2292HOPOPTS:
1283                 val = np->rxopt.bits.ohopopts;
1284                 break;
1285
1286         case IPV6_RECVDSTOPTS:
1287                 val = np->rxopt.bits.dstopts;
1288                 break;
1289
1290         case IPV6_2292DSTOPTS:
1291                 val = np->rxopt.bits.odstopts;
1292                 break;
1293
1294         case IPV6_TCLASS:
1295                 val = np->tclass;
1296                 break;
1297
1298         case IPV6_RECVTCLASS:
1299                 val = np->rxopt.bits.rxtclass;
1300                 break;
1301
1302         case IPV6_FLOWINFO:
1303                 val = np->rxopt.bits.rxflow;
1304                 break;
1305
1306         case IPV6_RECVPATHMTU:
1307                 val = np->rxopt.bits.rxpmtu;
1308                 break;
1309
1310         case IPV6_PATHMTU:
1311         {
1312                 struct dst_entry *dst;
1313                 struct ip6_mtuinfo mtuinfo;
1314
1315                 if (len < sizeof(mtuinfo))
1316                         return -EINVAL;
1317
1318                 len = sizeof(mtuinfo);
1319                 memset(&mtuinfo, 0, sizeof(mtuinfo));
1320
1321                 rcu_read_lock();
1322                 dst = __sk_dst_get(sk);
1323                 if (dst)
1324                         mtuinfo.ip6m_mtu = dst_mtu(dst);
1325                 rcu_read_unlock();
1326                 if (!mtuinfo.ip6m_mtu)
1327                         return -ENOTCONN;
1328
1329                 if (put_user(len, optlen))
1330                         return -EFAULT;
1331                 if (copy_to_user(optval, &mtuinfo, len))
1332                         return -EFAULT;
1333
1334                 return 0;
1335         }
1336
1337         case IPV6_TRANSPARENT:
1338                 val = inet_sk(sk)->transparent;
1339                 break;
1340
1341         case IPV6_FREEBIND:
1342                 val = inet_sk(sk)->freebind;
1343                 break;
1344
1345         case IPV6_RECVORIGDSTADDR:
1346                 val = np->rxopt.bits.rxorigdstaddr;
1347                 break;
1348
1349         case IPV6_UNICAST_HOPS:
1350         case IPV6_MULTICAST_HOPS:
1351         {
1352                 struct dst_entry *dst;
1353
1354                 if (optname == IPV6_UNICAST_HOPS)
1355                         val = np->hop_limit;
1356                 else
1357                         val = np->mcast_hops;
1358
1359                 if (val < 0) {
1360                         rcu_read_lock();
1361                         dst = __sk_dst_get(sk);
1362                         if (dst)
1363                                 val = ip6_dst_hoplimit(dst);
1364                         rcu_read_unlock();
1365                 }
1366
1367                 if (val < 0)
1368                         val = sock_net(sk)->ipv6.devconf_all->hop_limit;
1369                 break;
1370         }
1371
1372         case IPV6_MULTICAST_LOOP:
1373                 val = np->mc_loop;
1374                 break;
1375
1376         case IPV6_MULTICAST_IF:
1377                 val = np->mcast_oif;
1378                 break;
1379
1380         case IPV6_MULTICAST_ALL:
1381                 val = np->mc_all;
1382                 break;
1383
1384         case IPV6_UNICAST_IF:
1385                 val = (__force int)htonl((__u32) np->ucast_oif);
1386                 break;
1387
1388         case IPV6_MTU_DISCOVER:
1389                 val = np->pmtudisc;
1390                 break;
1391
1392         case IPV6_RECVERR:
1393                 val = np->recverr;
1394                 break;
1395
1396         case IPV6_FLOWINFO_SEND:
1397                 val = np->sndflow;
1398                 break;
1399
1400         case IPV6_FLOWLABEL_MGR:
1401         {
1402                 struct in6_flowlabel_req freq;
1403                 int flags;
1404
1405                 if (len < sizeof(freq))
1406                         return -EINVAL;
1407
1408                 if (copy_from_user(&freq, optval, sizeof(freq)))
1409                         return -EFAULT;
1410
1411                 if (freq.flr_action != IPV6_FL_A_GET)
1412                         return -EINVAL;
1413
1414                 len = sizeof(freq);
1415                 flags = freq.flr_flags;
1416
1417                 memset(&freq, 0, sizeof(freq));
1418
1419                 val = ipv6_flowlabel_opt_get(sk, &freq, flags);
1420                 if (val < 0)
1421                         return val;
1422
1423                 if (put_user(len, optlen))
1424                         return -EFAULT;
1425                 if (copy_to_user(optval, &freq, len))
1426                         return -EFAULT;
1427
1428                 return 0;
1429         }
1430
1431         case IPV6_ADDR_PREFERENCES:
1432                 val = 0;
1433
1434                 if (np->srcprefs & IPV6_PREFER_SRC_TMP)
1435                         val |= IPV6_PREFER_SRC_TMP;
1436                 else if (np->srcprefs & IPV6_PREFER_SRC_PUBLIC)
1437                         val |= IPV6_PREFER_SRC_PUBLIC;
1438                 else {
1439                         /* XXX: should we return system default? */
1440                         val |= IPV6_PREFER_SRC_PUBTMP_DEFAULT;
1441                 }
1442
1443                 if (np->srcprefs & IPV6_PREFER_SRC_COA)
1444                         val |= IPV6_PREFER_SRC_COA;
1445                 else
1446                         val |= IPV6_PREFER_SRC_HOME;
1447                 break;
1448
1449         case IPV6_MINHOPCOUNT:
1450                 val = np->min_hopcount;
1451                 break;
1452
1453         case IPV6_DONTFRAG:
1454                 val = np->dontfrag;
1455                 break;
1456
1457         case IPV6_AUTOFLOWLABEL:
1458                 val = ip6_autoflowlabel(sock_net(sk), np);
1459                 break;
1460
1461         case IPV6_RECVFRAGSIZE:
1462                 val = np->rxopt.bits.recvfragsize;
1463                 break;
1464
1465         case IPV6_ROUTER_ALERT_ISOLATE:
1466                 val = np->rtalert_isolate;
1467                 break;
1468
1469         case IPV6_RECVERR_RFC4884:
1470                 val = np->recverr_rfc4884;
1471                 break;
1472
1473         default:
1474                 return -ENOPROTOOPT;
1475         }
1476         len = min_t(unsigned int, sizeof(int), len);
1477         if (put_user(len, optlen))
1478                 return -EFAULT;
1479         if (copy_to_user(optval, &val, len))
1480                 return -EFAULT;
1481         return 0;
1482 }
1483
1484 int ipv6_getsockopt(struct sock *sk, int level, int optname,
1485                     char __user *optval, int __user *optlen)
1486 {
1487         int err;
1488
1489         if (level == SOL_IP && sk->sk_type != SOCK_RAW)
1490                 return udp_prot.getsockopt(sk, level, optname, optval, optlen);
1491
1492         if (level != SOL_IPV6)
1493                 return -ENOPROTOOPT;
1494
1495         err = do_ipv6_getsockopt(sk, level, optname, optval, optlen, 0);
1496 #ifdef CONFIG_NETFILTER
1497         /* we need to exclude all possible ENOPROTOOPTs except default case */
1498         if (err == -ENOPROTOOPT && optname != IPV6_2292PKTOPTIONS) {
1499                 int len;
1500
1501                 if (get_user(len, optlen))
1502                         return -EFAULT;
1503
1504                 err = nf_getsockopt(sk, PF_INET6, optname, optval, &len);
1505                 if (err >= 0)
1506                         err = put_user(len, optlen);
1507         }
1508 #endif
1509         return err;
1510 }
1511 EXPORT_SYMBOL(ipv6_getsockopt);