xref: /linux/net/ipv6/ipv6_sockglue.c (revision 8be4d31cb8aaeea27bde4b7ddb26e28a89062ebf)
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 
ip6_ra_control(struct sock * sk,int sel)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 
ipv6_update_options(struct sock * sk,struct ipv6_txoptions * opt)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 = unrcu_pointer(xchg(&inet6_sk(sk)->opt, RCU_INITIALIZER(opt)));
115 	sk_dst_reset(sk);
116 
117 	return opt;
118 }
119 
copy_group_source_from_sockptr(struct group_source_req * greqs,sockptr_t optval,int optlen)120 static int copy_group_source_from_sockptr(struct group_source_req *greqs,
121 		sockptr_t optval, int optlen)
122 {
123 	if (in_compat_syscall()) {
124 		struct compat_group_source_req gr32;
125 
126 		if (optlen < sizeof(gr32))
127 			return -EINVAL;
128 		if (copy_from_sockptr(&gr32, optval, sizeof(gr32)))
129 			return -EFAULT;
130 		greqs->gsr_interface = gr32.gsr_interface;
131 		greqs->gsr_group = gr32.gsr_group;
132 		greqs->gsr_source = gr32.gsr_source;
133 	} else {
134 		if (optlen < sizeof(*greqs))
135 			return -EINVAL;
136 		if (copy_from_sockptr(greqs, optval, sizeof(*greqs)))
137 			return -EFAULT;
138 	}
139 
140 	return 0;
141 }
142 
do_ipv6_mcast_group_source(struct sock * sk,int optname,sockptr_t optval,int optlen)143 static int do_ipv6_mcast_group_source(struct sock *sk, int optname,
144 		sockptr_t optval, int optlen)
145 {
146 	struct group_source_req greqs;
147 	int omode, add;
148 	int ret;
149 
150 	ret = copy_group_source_from_sockptr(&greqs, optval, optlen);
151 	if (ret)
152 		return ret;
153 
154 	if (greqs.gsr_group.ss_family != AF_INET6 ||
155 	    greqs.gsr_source.ss_family != AF_INET6)
156 		return -EADDRNOTAVAIL;
157 
158 	if (optname == MCAST_BLOCK_SOURCE) {
159 		omode = MCAST_EXCLUDE;
160 		add = 1;
161 	} else if (optname == MCAST_UNBLOCK_SOURCE) {
162 		omode = MCAST_EXCLUDE;
163 		add = 0;
164 	} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
165 		struct sockaddr_in6 *psin6;
166 		int retv;
167 
168 		psin6 = (struct sockaddr_in6 *)&greqs.gsr_group;
169 		retv = ipv6_sock_mc_join_ssm(sk, greqs.gsr_interface,
170 					     &psin6->sin6_addr,
171 					     MCAST_INCLUDE);
172 		/* prior join w/ different source is ok */
173 		if (retv && retv != -EADDRINUSE)
174 			return retv;
175 		omode = MCAST_INCLUDE;
176 		add = 1;
177 	} else /* MCAST_LEAVE_SOURCE_GROUP */ {
178 		omode = MCAST_INCLUDE;
179 		add = 0;
180 	}
181 	return ip6_mc_source(add, omode, sk, &greqs);
182 }
183 
ipv6_set_mcast_msfilter(struct sock * sk,sockptr_t optval,int optlen)184 static int ipv6_set_mcast_msfilter(struct sock *sk, sockptr_t optval,
185 		int optlen)
186 {
187 	struct group_filter *gsf;
188 	int ret;
189 
190 	if (optlen < GROUP_FILTER_SIZE(0))
191 		return -EINVAL;
192 	if (optlen > READ_ONCE(sock_net(sk)->core.sysctl_optmem_max))
193 		return -ENOBUFS;
194 
195 	gsf = memdup_sockptr(optval, optlen);
196 	if (IS_ERR(gsf))
197 		return PTR_ERR(gsf);
198 
199 	/* numsrc >= (4G-140)/128 overflow in 32 bits */
200 	ret = -ENOBUFS;
201 	if (gsf->gf_numsrc >= 0x1ffffffU ||
202 	    gsf->gf_numsrc > sysctl_mld_max_msf)
203 		goto out_free_gsf;
204 
205 	ret = -EINVAL;
206 	if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen)
207 		goto out_free_gsf;
208 
209 	ret = ip6_mc_msfilter(sk, gsf, gsf->gf_slist_flex);
210 out_free_gsf:
211 	kfree(gsf);
212 	return ret;
213 }
214 
compat_ipv6_set_mcast_msfilter(struct sock * sk,sockptr_t optval,int optlen)215 static int compat_ipv6_set_mcast_msfilter(struct sock *sk, sockptr_t optval,
216 		int optlen)
217 {
218 	const int size0 = offsetof(struct compat_group_filter, gf_slist_flex);
219 	struct compat_group_filter *gf32;
220 	void *p;
221 	int ret;
222 	int n;
223 
224 	if (optlen < size0)
225 		return -EINVAL;
226 	if (optlen > READ_ONCE(sock_net(sk)->core.sysctl_optmem_max) - 4)
227 		return -ENOBUFS;
228 
229 	p = kmalloc(optlen + 4, GFP_KERNEL);
230 	if (!p)
231 		return -ENOMEM;
232 
233 	gf32 = p + 4; /* we want ->gf_group and ->gf_slist_flex aligned */
234 	ret = -EFAULT;
235 	if (copy_from_sockptr(gf32, optval, optlen))
236 		goto out_free_p;
237 
238 	/* numsrc >= (4G-140)/128 overflow in 32 bits */
239 	ret = -ENOBUFS;
240 	n = gf32->gf_numsrc;
241 	if (n >= 0x1ffffffU || n > sysctl_mld_max_msf)
242 		goto out_free_p;
243 
244 	ret = -EINVAL;
245 	if (offsetof(struct compat_group_filter, gf_slist_flex[n]) > optlen)
246 		goto out_free_p;
247 
248 	ret = ip6_mc_msfilter(sk, &(struct group_filter){
249 			.gf_interface = gf32->gf_interface,
250 			.gf_group = gf32->gf_group,
251 			.gf_fmode = gf32->gf_fmode,
252 			.gf_numsrc = gf32->gf_numsrc}, gf32->gf_slist_flex);
253 
254 out_free_p:
255 	kfree(p);
256 	return ret;
257 }
258 
ipv6_mcast_join_leave(struct sock * sk,int optname,sockptr_t optval,int optlen)259 static int ipv6_mcast_join_leave(struct sock *sk, int optname,
260 		sockptr_t optval, int optlen)
261 {
262 	struct sockaddr_in6 *psin6;
263 	struct group_req greq;
264 
265 	if (optlen < sizeof(greq))
266 		return -EINVAL;
267 	if (copy_from_sockptr(&greq, optval, sizeof(greq)))
268 		return -EFAULT;
269 
270 	if (greq.gr_group.ss_family != AF_INET6)
271 		return -EADDRNOTAVAIL;
272 	psin6 = (struct sockaddr_in6 *)&greq.gr_group;
273 	if (optname == MCAST_JOIN_GROUP)
274 		return ipv6_sock_mc_join(sk, greq.gr_interface,
275 					 &psin6->sin6_addr);
276 	return ipv6_sock_mc_drop(sk, greq.gr_interface, &psin6->sin6_addr);
277 }
278 
compat_ipv6_mcast_join_leave(struct sock * sk,int optname,sockptr_t optval,int optlen)279 static int compat_ipv6_mcast_join_leave(struct sock *sk, int optname,
280 		sockptr_t optval, int optlen)
281 {
282 	struct compat_group_req gr32;
283 	struct sockaddr_in6 *psin6;
284 
285 	if (optlen < sizeof(gr32))
286 		return -EINVAL;
287 	if (copy_from_sockptr(&gr32, optval, sizeof(gr32)))
288 		return -EFAULT;
289 
290 	if (gr32.gr_group.ss_family != AF_INET6)
291 		return -EADDRNOTAVAIL;
292 	psin6 = (struct sockaddr_in6 *)&gr32.gr_group;
293 	if (optname == MCAST_JOIN_GROUP)
294 		return ipv6_sock_mc_join(sk, gr32.gr_interface,
295 					&psin6->sin6_addr);
296 	return ipv6_sock_mc_drop(sk, gr32.gr_interface, &psin6->sin6_addr);
297 }
298 
ipv6_set_opt_hdr(struct sock * sk,int optname,sockptr_t optval,int optlen)299 static int ipv6_set_opt_hdr(struct sock *sk, int optname, sockptr_t optval,
300 		int optlen)
301 {
302 	struct ipv6_pinfo *np = inet6_sk(sk);
303 	struct ipv6_opt_hdr *new = NULL;
304 	struct net *net = sock_net(sk);
305 	struct ipv6_txoptions *opt;
306 	int err;
307 
308 	/* hop-by-hop / destination options are privileged option */
309 	if (optname != IPV6_RTHDR && !sockopt_ns_capable(net->user_ns, CAP_NET_RAW))
310 		return -EPERM;
311 
312 	/* remove any sticky options header with a zero option
313 	 * length, per RFC3542.
314 	 */
315 	if (optlen > 0) {
316 		if (sockptr_is_null(optval))
317 			return -EINVAL;
318 		if (optlen < sizeof(struct ipv6_opt_hdr) ||
319 		    optlen & 0x7 ||
320 		    optlen > 8 * 255)
321 			return -EINVAL;
322 
323 		new = memdup_sockptr(optval, optlen);
324 		if (IS_ERR(new))
325 			return PTR_ERR(new);
326 		if (unlikely(ipv6_optlen(new) > optlen)) {
327 			kfree(new);
328 			return -EINVAL;
329 		}
330 	}
331 
332 	opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
333 	opt = ipv6_renew_options(sk, opt, optname, new);
334 	kfree(new);
335 	if (IS_ERR(opt))
336 		return PTR_ERR(opt);
337 
338 	/* routing header option needs extra check */
339 	err = -EINVAL;
340 	if (optname == IPV6_RTHDR && opt && opt->srcrt) {
341 		struct ipv6_rt_hdr *rthdr = opt->srcrt;
342 		switch (rthdr->type) {
343 #if IS_ENABLED(CONFIG_IPV6_MIP6)
344 		case IPV6_SRCRT_TYPE_2:
345 			if (rthdr->hdrlen != 2 || rthdr->segments_left != 1)
346 				goto sticky_done;
347 			break;
348 #endif
349 		case IPV6_SRCRT_TYPE_4:
350 		{
351 			struct ipv6_sr_hdr *srh =
352 				(struct ipv6_sr_hdr *)opt->srcrt;
353 
354 			if (!seg6_validate_srh(srh, optlen, false))
355 				goto sticky_done;
356 			break;
357 		}
358 		default:
359 			goto sticky_done;
360 		}
361 	}
362 
363 	err = 0;
364 	opt = ipv6_update_options(sk, opt);
365 sticky_done:
366 	if (opt) {
367 		atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
368 		txopt_put(opt);
369 	}
370 	return err;
371 }
372 
do_ipv6_setsockopt(struct sock * sk,int level,int optname,sockptr_t optval,unsigned int optlen)373 int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
374 		       sockptr_t optval, unsigned int optlen)
375 {
376 	struct ipv6_pinfo *np = inet6_sk(sk);
377 	struct net *net = sock_net(sk);
378 	int retv = -ENOPROTOOPT;
379 	int val, valbool;
380 
381 	if (sockptr_is_null(optval))
382 		val = 0;
383 	else {
384 		if (optlen >= sizeof(int)) {
385 			if (copy_from_sockptr(&val, optval, sizeof(val)))
386 				return -EFAULT;
387 		} else
388 			val = 0;
389 	}
390 
391 	valbool = (val != 0);
392 
393 	if (ip6_mroute_opt(optname))
394 		return ip6_mroute_setsockopt(sk, optname, optval, optlen);
395 
396 	/* Handle options that can be set without locking the socket. */
397 	switch (optname) {
398 	case IPV6_UNICAST_HOPS:
399 		if (optlen < sizeof(int))
400 			return -EINVAL;
401 		if (val > 255 || val < -1)
402 			return -EINVAL;
403 		WRITE_ONCE(np->hop_limit, val);
404 		return 0;
405 	case IPV6_MULTICAST_LOOP:
406 		if (optlen < sizeof(int))
407 			return -EINVAL;
408 		if (val != valbool)
409 			return -EINVAL;
410 		inet6_assign_bit(MC6_LOOP, sk, valbool);
411 		return 0;
412 	case IPV6_MULTICAST_HOPS:
413 		if (sk->sk_type == SOCK_STREAM)
414 			return retv;
415 		if (optlen < sizeof(int))
416 			return -EINVAL;
417 		if (val > 255 || val < -1)
418 			return -EINVAL;
419 		WRITE_ONCE(np->mcast_hops,
420 			   val == -1 ? IPV6_DEFAULT_MCASTHOPS : val);
421 		return 0;
422 	case IPV6_MTU:
423 		if (optlen < sizeof(int))
424 			return -EINVAL;
425 		if (val && val < IPV6_MIN_MTU)
426 			return -EINVAL;
427 		WRITE_ONCE(np->frag_size, val);
428 		return 0;
429 	case IPV6_MINHOPCOUNT:
430 		if (optlen < sizeof(int))
431 			return -EINVAL;
432 		if (val < 0 || val > 255)
433 			return -EINVAL;
434 
435 		if (val)
436 			static_branch_enable(&ip6_min_hopcount);
437 
438 		/* tcp_v6_err() and tcp_v6_rcv() might read min_hopcount
439 		 * while we are changing it.
440 		 */
441 		WRITE_ONCE(np->min_hopcount, val);
442 		return 0;
443 	case IPV6_RECVERR_RFC4884:
444 		if (optlen < sizeof(int))
445 			return -EINVAL;
446 		if (val < 0 || val > 1)
447 			return -EINVAL;
448 		inet6_assign_bit(RECVERR6_RFC4884, sk, valbool);
449 		return 0;
450 	case IPV6_MULTICAST_ALL:
451 		if (optlen < sizeof(int))
452 			return -EINVAL;
453 		inet6_assign_bit(MC6_ALL, sk, valbool);
454 		return 0;
455 	case IPV6_AUTOFLOWLABEL:
456 		inet6_assign_bit(AUTOFLOWLABEL, sk, valbool);
457 		inet6_set_bit(AUTOFLOWLABEL_SET, sk);
458 		return 0;
459 	case IPV6_DONTFRAG:
460 		inet6_assign_bit(DONTFRAG, sk, valbool);
461 		return 0;
462 	case IPV6_RECVERR:
463 		if (optlen < sizeof(int))
464 			return -EINVAL;
465 		inet6_assign_bit(RECVERR6, sk, valbool);
466 		if (!val)
467 			skb_errqueue_purge(&sk->sk_error_queue);
468 		return 0;
469 	case IPV6_ROUTER_ALERT_ISOLATE:
470 		if (optlen < sizeof(int))
471 			return -EINVAL;
472 		inet6_assign_bit(RTALERT_ISOLATE, sk, valbool);
473 		return 0;
474 	case IPV6_MTU_DISCOVER:
475 		if (optlen < sizeof(int))
476 			return -EINVAL;
477 		if (val < IPV6_PMTUDISC_DONT || val > IPV6_PMTUDISC_OMIT)
478 			return -EINVAL;
479 		WRITE_ONCE(np->pmtudisc, val);
480 		return 0;
481 	case IPV6_FLOWINFO_SEND:
482 		if (optlen < sizeof(int))
483 			return -EINVAL;
484 		inet6_assign_bit(SNDFLOW, sk, valbool);
485 		return 0;
486 	case IPV6_ADDR_PREFERENCES:
487 		if (optlen < sizeof(int))
488 			return -EINVAL;
489 		return ip6_sock_set_addr_preferences(sk, val);
490 	case IPV6_MULTICAST_IF:
491 		if (sk->sk_type == SOCK_STREAM)
492 			return -ENOPROTOOPT;
493 		if (optlen < sizeof(int))
494 			return -EINVAL;
495 		if (val) {
496 			struct net_device *dev;
497 			int bound_dev_if, midx;
498 
499 			rcu_read_lock();
500 
501 			dev = dev_get_by_index_rcu(net, val);
502 			if (!dev) {
503 				rcu_read_unlock();
504 				return -ENODEV;
505 			}
506 			midx = l3mdev_master_ifindex_rcu(dev);
507 
508 			rcu_read_unlock();
509 
510 			bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
511 			if (bound_dev_if &&
512 			    bound_dev_if != val &&
513 			    (!midx || midx != bound_dev_if))
514 				return -EINVAL;
515 		}
516 		WRITE_ONCE(np->mcast_oif, val);
517 		return 0;
518 	case IPV6_UNICAST_IF:
519 	{
520 		struct net_device *dev;
521 		int ifindex;
522 
523 		if (optlen != sizeof(int))
524 			return -EINVAL;
525 
526 		ifindex = (__force int)ntohl((__force __be32)val);
527 		if (!ifindex) {
528 			WRITE_ONCE(np->ucast_oif, 0);
529 			return 0;
530 		}
531 
532 		dev = dev_get_by_index(net, ifindex);
533 		if (!dev)
534 			return -EADDRNOTAVAIL;
535 		dev_put(dev);
536 
537 		if (READ_ONCE(sk->sk_bound_dev_if))
538 			return -EINVAL;
539 
540 		WRITE_ONCE(np->ucast_oif, ifindex);
541 		return 0;
542 	}
543 	}
544 
545 	sockopt_lock_sock(sk);
546 
547 	/* Another thread has converted the socket into IPv4 with
548 	 * IPV6_ADDRFORM concurrently.
549 	 */
550 	if (unlikely(sk->sk_family != AF_INET6))
551 		goto unlock;
552 
553 	switch (optname) {
554 
555 	case IPV6_ADDRFORM:
556 		if (optlen < sizeof(int))
557 			goto e_inval;
558 		if (val == PF_INET) {
559 			if (sk->sk_type == SOCK_RAW)
560 				break;
561 
562 			if (sk->sk_protocol == IPPROTO_UDP ||
563 			    sk->sk_protocol == IPPROTO_UDPLITE) {
564 				struct udp_sock *up = udp_sk(sk);
565 				if (up->pending == AF_INET6) {
566 					retv = -EBUSY;
567 					break;
568 				}
569 			} else if (sk->sk_protocol == IPPROTO_TCP) {
570 				if (sk->sk_prot != &tcpv6_prot) {
571 					retv = -EBUSY;
572 					break;
573 				}
574 			} else {
575 				break;
576 			}
577 
578 			if (sk->sk_state != TCP_ESTABLISHED) {
579 				retv = -ENOTCONN;
580 				break;
581 			}
582 
583 			if (ipv6_only_sock(sk) ||
584 			    !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) {
585 				retv = -EADDRNOTAVAIL;
586 				break;
587 			}
588 
589 			__ipv6_sock_mc_close(sk);
590 			__ipv6_sock_ac_close(sk);
591 
592 			if (sk->sk_protocol == IPPROTO_TCP) {
593 				struct inet_connection_sock *icsk = inet_csk(sk);
594 
595 				sock_prot_inuse_add(net, sk->sk_prot, -1);
596 				sock_prot_inuse_add(net, &tcp_prot, 1);
597 
598 				/* Paired with READ_ONCE(sk->sk_prot) in inet6_stream_ops */
599 				WRITE_ONCE(sk->sk_prot, &tcp_prot);
600 				/* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
601 				WRITE_ONCE(icsk->icsk_af_ops, &ipv4_specific);
602 				WRITE_ONCE(sk->sk_socket->ops, &inet_stream_ops);
603 				WRITE_ONCE(sk->sk_family, PF_INET);
604 				tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
605 			} else {
606 				struct proto *prot = &udp_prot;
607 
608 				if (sk->sk_protocol == IPPROTO_UDPLITE)
609 					prot = &udplite_prot;
610 
611 				sock_prot_inuse_add(net, sk->sk_prot, -1);
612 				sock_prot_inuse_add(net, prot, 1);
613 
614 				/* Paired with READ_ONCE(sk->sk_prot) in inet6_dgram_ops */
615 				WRITE_ONCE(sk->sk_prot, prot);
616 				WRITE_ONCE(sk->sk_socket->ops, &inet_dgram_ops);
617 				WRITE_ONCE(sk->sk_family, PF_INET);
618 			}
619 
620 			/* Disable all options not to allocate memory anymore,
621 			 * but there is still a race.  See the lockless path
622 			 * in udpv6_sendmsg() and ipv6_local_rxpmtu().
623 			 */
624 			np->rxopt.all = 0;
625 
626 			inet6_cleanup_sock(sk);
627 
628 			module_put(THIS_MODULE);
629 			retv = 0;
630 			break;
631 		}
632 		goto e_inval;
633 
634 	case IPV6_V6ONLY:
635 		if (optlen < sizeof(int) ||
636 		    inet_sk(sk)->inet_num)
637 			goto e_inval;
638 		sk->sk_ipv6only = valbool;
639 		retv = 0;
640 		break;
641 
642 	case IPV6_RECVPKTINFO:
643 		if (optlen < sizeof(int))
644 			goto e_inval;
645 		np->rxopt.bits.rxinfo = valbool;
646 		retv = 0;
647 		break;
648 
649 	case IPV6_2292PKTINFO:
650 		if (optlen < sizeof(int))
651 			goto e_inval;
652 		np->rxopt.bits.rxoinfo = valbool;
653 		retv = 0;
654 		break;
655 
656 	case IPV6_RECVHOPLIMIT:
657 		if (optlen < sizeof(int))
658 			goto e_inval;
659 		np->rxopt.bits.rxhlim = valbool;
660 		retv = 0;
661 		break;
662 
663 	case IPV6_2292HOPLIMIT:
664 		if (optlen < sizeof(int))
665 			goto e_inval;
666 		np->rxopt.bits.rxohlim = valbool;
667 		retv = 0;
668 		break;
669 
670 	case IPV6_RECVRTHDR:
671 		if (optlen < sizeof(int))
672 			goto e_inval;
673 		np->rxopt.bits.srcrt = valbool;
674 		retv = 0;
675 		break;
676 
677 	case IPV6_2292RTHDR:
678 		if (optlen < sizeof(int))
679 			goto e_inval;
680 		np->rxopt.bits.osrcrt = valbool;
681 		retv = 0;
682 		break;
683 
684 	case IPV6_RECVHOPOPTS:
685 		if (optlen < sizeof(int))
686 			goto e_inval;
687 		np->rxopt.bits.hopopts = valbool;
688 		retv = 0;
689 		break;
690 
691 	case IPV6_2292HOPOPTS:
692 		if (optlen < sizeof(int))
693 			goto e_inval;
694 		np->rxopt.bits.ohopopts = valbool;
695 		retv = 0;
696 		break;
697 
698 	case IPV6_RECVDSTOPTS:
699 		if (optlen < sizeof(int))
700 			goto e_inval;
701 		np->rxopt.bits.dstopts = valbool;
702 		retv = 0;
703 		break;
704 
705 	case IPV6_2292DSTOPTS:
706 		if (optlen < sizeof(int))
707 			goto e_inval;
708 		np->rxopt.bits.odstopts = valbool;
709 		retv = 0;
710 		break;
711 
712 	case IPV6_TCLASS:
713 		if (optlen < sizeof(int))
714 			goto e_inval;
715 		if (val < -1 || val > 0xff)
716 			goto e_inval;
717 		/* RFC 3542, 6.5: default traffic class of 0x0 */
718 		if (val == -1)
719 			val = 0;
720 		if (sk->sk_type == SOCK_STREAM) {
721 			val &= ~INET_ECN_MASK;
722 			val |= np->tclass & INET_ECN_MASK;
723 		}
724 		if (np->tclass != val) {
725 			np->tclass = val;
726 			sk_dst_reset(sk);
727 		}
728 		retv = 0;
729 		break;
730 
731 	case IPV6_RECVTCLASS:
732 		if (optlen < sizeof(int))
733 			goto e_inval;
734 		np->rxopt.bits.rxtclass = valbool;
735 		retv = 0;
736 		break;
737 
738 	case IPV6_FLOWINFO:
739 		if (optlen < sizeof(int))
740 			goto e_inval;
741 		np->rxopt.bits.rxflow = valbool;
742 		retv = 0;
743 		break;
744 
745 	case IPV6_RECVPATHMTU:
746 		if (optlen < sizeof(int))
747 			goto e_inval;
748 		np->rxopt.bits.rxpmtu = valbool;
749 		retv = 0;
750 		break;
751 
752 	case IPV6_TRANSPARENT:
753 		if (valbool && !sockopt_ns_capable(net->user_ns, CAP_NET_RAW) &&
754 		    !sockopt_ns_capable(net->user_ns, CAP_NET_ADMIN)) {
755 			retv = -EPERM;
756 			break;
757 		}
758 		if (optlen < sizeof(int))
759 			goto e_inval;
760 		/* we don't have a separate transparent bit for IPV6 we use the one in the IPv4 socket */
761 		inet_assign_bit(TRANSPARENT, sk, valbool);
762 		retv = 0;
763 		break;
764 
765 	case IPV6_FREEBIND:
766 		if (optlen < sizeof(int))
767 			goto e_inval;
768 		/* we also don't have a separate freebind bit for IPV6 */
769 		inet_assign_bit(FREEBIND, sk, valbool);
770 		retv = 0;
771 		break;
772 
773 	case IPV6_RECVORIGDSTADDR:
774 		if (optlen < sizeof(int))
775 			goto e_inval;
776 		np->rxopt.bits.rxorigdstaddr = valbool;
777 		retv = 0;
778 		break;
779 
780 	case IPV6_HOPOPTS:
781 	case IPV6_RTHDRDSTOPTS:
782 	case IPV6_RTHDR:
783 	case IPV6_DSTOPTS:
784 		retv = ipv6_set_opt_hdr(sk, optname, optval, optlen);
785 		break;
786 
787 	case IPV6_PKTINFO:
788 	{
789 		struct in6_pktinfo pkt;
790 
791 		if (optlen == 0)
792 			goto e_inval;
793 		else if (optlen < sizeof(struct in6_pktinfo) ||
794 			 sockptr_is_null(optval))
795 			goto e_inval;
796 
797 		if (copy_from_sockptr(&pkt, optval, sizeof(pkt))) {
798 			retv = -EFAULT;
799 			break;
800 		}
801 		if (!sk_dev_equal_l3scope(sk, pkt.ipi6_ifindex))
802 			goto e_inval;
803 
804 		np->sticky_pktinfo.ipi6_ifindex = pkt.ipi6_ifindex;
805 		np->sticky_pktinfo.ipi6_addr = pkt.ipi6_addr;
806 		retv = 0;
807 		break;
808 	}
809 
810 	case IPV6_2292PKTOPTIONS:
811 	{
812 		struct ipv6_txoptions *opt = NULL;
813 		struct msghdr msg;
814 		struct flowi6 fl6;
815 		struct ipcm6_cookie ipc6;
816 
817 		memset(&fl6, 0, sizeof(fl6));
818 		fl6.flowi6_oif = sk->sk_bound_dev_if;
819 		fl6.flowi6_mark = sk->sk_mark;
820 
821 		if (optlen == 0)
822 			goto update;
823 
824 		/* 1K is probably excessive
825 		 * 1K is surely not enough, 2K per standard header is 16K.
826 		 */
827 		retv = -EINVAL;
828 		if (optlen > 64*1024)
829 			break;
830 
831 		opt = sock_kmalloc(sk, sizeof(*opt) + optlen, GFP_KERNEL);
832 		retv = -ENOBUFS;
833 		if (!opt)
834 			break;
835 
836 		memset(opt, 0, sizeof(*opt));
837 		refcount_set(&opt->refcnt, 1);
838 		opt->tot_len = sizeof(*opt) + optlen;
839 		retv = -EFAULT;
840 		if (copy_from_sockptr(opt + 1, optval, optlen))
841 			goto done;
842 
843 		msg.msg_controllen = optlen;
844 		msg.msg_control_is_user = false;
845 		msg.msg_control = (void *)(opt+1);
846 		ipc6.opt = opt;
847 
848 		retv = ip6_datagram_send_ctl(net, sk, &msg, &fl6, &ipc6);
849 		if (retv)
850 			goto done;
851 update:
852 		retv = 0;
853 		opt = ipv6_update_options(sk, opt);
854 done:
855 		if (opt) {
856 			atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
857 			txopt_put(opt);
858 		}
859 		break;
860 	}
861 
862 	case IPV6_ADD_MEMBERSHIP:
863 	case IPV6_DROP_MEMBERSHIP:
864 	{
865 		struct ipv6_mreq mreq;
866 
867 		if (optlen < sizeof(struct ipv6_mreq))
868 			goto e_inval;
869 
870 		retv = -EPROTO;
871 		if (inet_test_bit(IS_ICSK, sk))
872 			break;
873 
874 		retv = -EFAULT;
875 		if (copy_from_sockptr(&mreq, optval, sizeof(struct ipv6_mreq)))
876 			break;
877 
878 		if (optname == IPV6_ADD_MEMBERSHIP)
879 			retv = ipv6_sock_mc_join(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr);
880 		else
881 			retv = ipv6_sock_mc_drop(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr);
882 		break;
883 	}
884 	case IPV6_JOIN_ANYCAST:
885 	case IPV6_LEAVE_ANYCAST:
886 	{
887 		struct ipv6_mreq mreq;
888 
889 		if (optlen < sizeof(struct ipv6_mreq))
890 			goto e_inval;
891 
892 		retv = -EFAULT;
893 		if (copy_from_sockptr(&mreq, optval, sizeof(struct ipv6_mreq)))
894 			break;
895 
896 		if (optname == IPV6_JOIN_ANYCAST)
897 			retv = ipv6_sock_ac_join(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_acaddr);
898 		else
899 			retv = ipv6_sock_ac_drop(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_acaddr);
900 		break;
901 	}
902 	case MCAST_JOIN_GROUP:
903 	case MCAST_LEAVE_GROUP:
904 		if (in_compat_syscall())
905 			retv = compat_ipv6_mcast_join_leave(sk, optname, optval,
906 							    optlen);
907 		else
908 			retv = ipv6_mcast_join_leave(sk, optname, optval,
909 						     optlen);
910 		break;
911 	case MCAST_JOIN_SOURCE_GROUP:
912 	case MCAST_LEAVE_SOURCE_GROUP:
913 	case MCAST_BLOCK_SOURCE:
914 	case MCAST_UNBLOCK_SOURCE:
915 		retv = do_ipv6_mcast_group_source(sk, optname, optval, optlen);
916 		break;
917 	case MCAST_MSFILTER:
918 		if (in_compat_syscall())
919 			retv = compat_ipv6_set_mcast_msfilter(sk, optval,
920 							      optlen);
921 		else
922 			retv = ipv6_set_mcast_msfilter(sk, optval, optlen);
923 		break;
924 	case IPV6_ROUTER_ALERT:
925 		if (optlen < sizeof(int))
926 			goto e_inval;
927 		retv = ip6_ra_control(sk, val);
928 		if (retv == 0)
929 			inet6_assign_bit(RTALERT, sk, valbool);
930 		break;
931 	case IPV6_FLOWLABEL_MGR:
932 		retv = ipv6_flowlabel_opt(sk, optval, optlen);
933 		break;
934 	case IPV6_IPSEC_POLICY:
935 	case IPV6_XFRM_POLICY:
936 		retv = -EPERM;
937 		if (!sockopt_ns_capable(net->user_ns, CAP_NET_ADMIN))
938 			break;
939 		retv = xfrm_user_policy(sk, optname, optval, optlen);
940 		break;
941 
942 	case IPV6_RECVFRAGSIZE:
943 		np->rxopt.bits.recvfragsize = valbool;
944 		retv = 0;
945 		break;
946 	}
947 
948 unlock:
949 	sockopt_release_sock(sk);
950 
951 	return retv;
952 
953 e_inval:
954 	retv = -EINVAL;
955 	goto unlock;
956 }
957 
ipv6_setsockopt(struct sock * sk,int level,int optname,sockptr_t optval,unsigned int optlen)958 int ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
959 		    unsigned int optlen)
960 {
961 	int err;
962 
963 	if (level == SOL_IP && sk->sk_type != SOCK_RAW)
964 		return ip_setsockopt(sk, level, optname, optval, optlen);
965 
966 	if (level != SOL_IPV6)
967 		return -ENOPROTOOPT;
968 
969 	err = do_ipv6_setsockopt(sk, level, optname, optval, optlen);
970 #ifdef CONFIG_NETFILTER
971 	/* we need to exclude all possible ENOPROTOOPTs except default case */
972 	if (err == -ENOPROTOOPT && optname != IPV6_IPSEC_POLICY &&
973 			optname != IPV6_XFRM_POLICY)
974 		err = nf_setsockopt(sk, PF_INET6, optname, optval, optlen);
975 #endif
976 	return err;
977 }
978 EXPORT_SYMBOL(ipv6_setsockopt);
979 
ipv6_getsockopt_sticky(struct sock * sk,struct ipv6_txoptions * opt,int optname,sockptr_t optval,int len)980 static int ipv6_getsockopt_sticky(struct sock *sk, struct ipv6_txoptions *opt,
981 				  int optname, sockptr_t optval, int len)
982 {
983 	struct ipv6_opt_hdr *hdr;
984 
985 	if (!opt)
986 		return 0;
987 
988 	switch (optname) {
989 	case IPV6_HOPOPTS:
990 		hdr = opt->hopopt;
991 		break;
992 	case IPV6_RTHDRDSTOPTS:
993 		hdr = opt->dst0opt;
994 		break;
995 	case IPV6_RTHDR:
996 		hdr = (struct ipv6_opt_hdr *)opt->srcrt;
997 		break;
998 	case IPV6_DSTOPTS:
999 		hdr = opt->dst1opt;
1000 		break;
1001 	default:
1002 		return -EINVAL;	/* should not happen */
1003 	}
1004 
1005 	if (!hdr)
1006 		return 0;
1007 
1008 	len = min_t(unsigned int, len, ipv6_optlen(hdr));
1009 	if (copy_to_sockptr(optval, hdr, len))
1010 		return -EFAULT;
1011 	return len;
1012 }
1013 
ipv6_get_msfilter(struct sock * sk,sockptr_t optval,sockptr_t optlen,int len)1014 static int ipv6_get_msfilter(struct sock *sk, sockptr_t optval,
1015 			     sockptr_t optlen, int len)
1016 {
1017 	const int size0 = offsetof(struct group_filter, gf_slist_flex);
1018 	struct group_filter gsf;
1019 	int num;
1020 	int err;
1021 
1022 	if (len < size0)
1023 		return -EINVAL;
1024 	if (copy_from_sockptr(&gsf, optval, size0))
1025 		return -EFAULT;
1026 	if (gsf.gf_group.ss_family != AF_INET6)
1027 		return -EADDRNOTAVAIL;
1028 	num = gsf.gf_numsrc;
1029 	sockopt_lock_sock(sk);
1030 	err = ip6_mc_msfget(sk, &gsf, optval, size0);
1031 	if (!err) {
1032 		if (num > gsf.gf_numsrc)
1033 			num = gsf.gf_numsrc;
1034 		len = GROUP_FILTER_SIZE(num);
1035 		if (copy_to_sockptr(optlen, &len, sizeof(int)) ||
1036 		    copy_to_sockptr(optval, &gsf, size0))
1037 			err = -EFAULT;
1038 	}
1039 	sockopt_release_sock(sk);
1040 	return err;
1041 }
1042 
compat_ipv6_get_msfilter(struct sock * sk,sockptr_t optval,sockptr_t optlen,int len)1043 static int compat_ipv6_get_msfilter(struct sock *sk, sockptr_t optval,
1044 				    sockptr_t optlen, int len)
1045 {
1046 	const int size0 = offsetof(struct compat_group_filter, gf_slist_flex);
1047 	struct compat_group_filter gf32;
1048 	struct group_filter gf;
1049 	int err;
1050 	int num;
1051 
1052 	if (len < size0)
1053 		return -EINVAL;
1054 
1055 	if (copy_from_sockptr(&gf32, optval, size0))
1056 		return -EFAULT;
1057 	gf.gf_interface = gf32.gf_interface;
1058 	gf.gf_fmode = gf32.gf_fmode;
1059 	num = gf.gf_numsrc = gf32.gf_numsrc;
1060 	gf.gf_group = gf32.gf_group;
1061 
1062 	if (gf.gf_group.ss_family != AF_INET6)
1063 		return -EADDRNOTAVAIL;
1064 
1065 	sockopt_lock_sock(sk);
1066 	err = ip6_mc_msfget(sk, &gf, optval, size0);
1067 	sockopt_release_sock(sk);
1068 	if (err)
1069 		return err;
1070 	if (num > gf.gf_numsrc)
1071 		num = gf.gf_numsrc;
1072 	len = GROUP_FILTER_SIZE(num) - (sizeof(gf)-sizeof(gf32));
1073 	if (copy_to_sockptr(optlen, &len, sizeof(int)) ||
1074 	    copy_to_sockptr_offset(optval, offsetof(struct compat_group_filter, gf_fmode),
1075 				   &gf.gf_fmode, sizeof(gf32.gf_fmode)) ||
1076 	    copy_to_sockptr_offset(optval, offsetof(struct compat_group_filter, gf_numsrc),
1077 				   &gf.gf_numsrc, sizeof(gf32.gf_numsrc)))
1078 		return -EFAULT;
1079 	return 0;
1080 }
1081 
do_ipv6_getsockopt(struct sock * sk,int level,int optname,sockptr_t optval,sockptr_t optlen)1082 int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
1083 		       sockptr_t optval, sockptr_t optlen)
1084 {
1085 	struct ipv6_pinfo *np = inet6_sk(sk);
1086 	int len;
1087 	int val;
1088 
1089 	if (ip6_mroute_opt(optname))
1090 		return ip6_mroute_getsockopt(sk, optname, optval, optlen);
1091 
1092 	if (copy_from_sockptr(&len, optlen, sizeof(int)))
1093 		return -EFAULT;
1094 	switch (optname) {
1095 	case IPV6_ADDRFORM:
1096 		if (sk->sk_protocol != IPPROTO_UDP &&
1097 		    sk->sk_protocol != IPPROTO_UDPLITE &&
1098 		    sk->sk_protocol != IPPROTO_TCP)
1099 			return -ENOPROTOOPT;
1100 		if (sk->sk_state != TCP_ESTABLISHED)
1101 			return -ENOTCONN;
1102 		val = sk->sk_family;
1103 		break;
1104 	case MCAST_MSFILTER:
1105 		if (in_compat_syscall())
1106 			return compat_ipv6_get_msfilter(sk, optval, optlen, len);
1107 		return ipv6_get_msfilter(sk, optval, optlen, len);
1108 	case IPV6_2292PKTOPTIONS:
1109 	{
1110 		struct msghdr msg;
1111 		struct sk_buff *skb;
1112 
1113 		if (sk->sk_type != SOCK_STREAM)
1114 			return -ENOPROTOOPT;
1115 
1116 		if (optval.is_kernel) {
1117 			msg.msg_control_is_user = false;
1118 			msg.msg_control = optval.kernel;
1119 		} else {
1120 			msg.msg_control_is_user = true;
1121 			msg.msg_control_user = optval.user;
1122 		}
1123 		msg.msg_controllen = len;
1124 		msg.msg_flags = 0;
1125 
1126 		sockopt_lock_sock(sk);
1127 		skb = np->pktoptions;
1128 		if (skb)
1129 			ip6_datagram_recv_ctl(sk, &msg, skb);
1130 		sockopt_release_sock(sk);
1131 		if (!skb) {
1132 			if (np->rxopt.bits.rxinfo) {
1133 				int mcast_oif = READ_ONCE(np->mcast_oif);
1134 				struct in6_pktinfo src_info;
1135 
1136 				src_info.ipi6_ifindex = mcast_oif ? :
1137 					np->sticky_pktinfo.ipi6_ifindex;
1138 				src_info.ipi6_addr = mcast_oif ? sk->sk_v6_daddr : np->sticky_pktinfo.ipi6_addr;
1139 				put_cmsg(&msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
1140 			}
1141 			if (np->rxopt.bits.rxhlim) {
1142 				int hlim = READ_ONCE(np->mcast_hops);
1143 
1144 				put_cmsg(&msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
1145 			}
1146 			if (np->rxopt.bits.rxtclass) {
1147 				int tclass = (int)ip6_tclass(np->rcv_flowinfo);
1148 
1149 				put_cmsg(&msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
1150 			}
1151 			if (np->rxopt.bits.rxoinfo) {
1152 				int mcast_oif = READ_ONCE(np->mcast_oif);
1153 				struct in6_pktinfo src_info;
1154 
1155 				src_info.ipi6_ifindex = mcast_oif ? :
1156 					np->sticky_pktinfo.ipi6_ifindex;
1157 				src_info.ipi6_addr = mcast_oif ? sk->sk_v6_daddr :
1158 								 np->sticky_pktinfo.ipi6_addr;
1159 				put_cmsg(&msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
1160 			}
1161 			if (np->rxopt.bits.rxohlim) {
1162 				int hlim = READ_ONCE(np->mcast_hops);
1163 
1164 				put_cmsg(&msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
1165 			}
1166 			if (np->rxopt.bits.rxflow) {
1167 				__be32 flowinfo = np->rcv_flowinfo;
1168 
1169 				put_cmsg(&msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
1170 			}
1171 		}
1172 		len -= msg.msg_controllen;
1173 		return copy_to_sockptr(optlen, &len, sizeof(int));
1174 	}
1175 	case IPV6_MTU:
1176 	{
1177 		struct dst_entry *dst;
1178 
1179 		val = 0;
1180 		rcu_read_lock();
1181 		dst = __sk_dst_get(sk);
1182 		if (dst)
1183 			val = dst_mtu(dst);
1184 		rcu_read_unlock();
1185 		if (!val)
1186 			return -ENOTCONN;
1187 		break;
1188 	}
1189 
1190 	case IPV6_V6ONLY:
1191 		val = sk->sk_ipv6only;
1192 		break;
1193 
1194 	case IPV6_RECVPKTINFO:
1195 		val = np->rxopt.bits.rxinfo;
1196 		break;
1197 
1198 	case IPV6_2292PKTINFO:
1199 		val = np->rxopt.bits.rxoinfo;
1200 		break;
1201 
1202 	case IPV6_RECVHOPLIMIT:
1203 		val = np->rxopt.bits.rxhlim;
1204 		break;
1205 
1206 	case IPV6_2292HOPLIMIT:
1207 		val = np->rxopt.bits.rxohlim;
1208 		break;
1209 
1210 	case IPV6_RECVRTHDR:
1211 		val = np->rxopt.bits.srcrt;
1212 		break;
1213 
1214 	case IPV6_2292RTHDR:
1215 		val = np->rxopt.bits.osrcrt;
1216 		break;
1217 
1218 	case IPV6_HOPOPTS:
1219 	case IPV6_RTHDRDSTOPTS:
1220 	case IPV6_RTHDR:
1221 	case IPV6_DSTOPTS:
1222 	{
1223 		struct ipv6_txoptions *opt;
1224 
1225 		sockopt_lock_sock(sk);
1226 		opt = rcu_dereference_protected(np->opt,
1227 						lockdep_sock_is_held(sk));
1228 		len = ipv6_getsockopt_sticky(sk, opt, optname, optval, len);
1229 		sockopt_release_sock(sk);
1230 		/* check if ipv6_getsockopt_sticky() returns err code */
1231 		if (len < 0)
1232 			return len;
1233 		return copy_to_sockptr(optlen, &len, sizeof(int));
1234 	}
1235 
1236 	case IPV6_RECVHOPOPTS:
1237 		val = np->rxopt.bits.hopopts;
1238 		break;
1239 
1240 	case IPV6_2292HOPOPTS:
1241 		val = np->rxopt.bits.ohopopts;
1242 		break;
1243 
1244 	case IPV6_RECVDSTOPTS:
1245 		val = np->rxopt.bits.dstopts;
1246 		break;
1247 
1248 	case IPV6_2292DSTOPTS:
1249 		val = np->rxopt.bits.odstopts;
1250 		break;
1251 
1252 	case IPV6_TCLASS:
1253 		val = np->tclass;
1254 		break;
1255 
1256 	case IPV6_RECVTCLASS:
1257 		val = np->rxopt.bits.rxtclass;
1258 		break;
1259 
1260 	case IPV6_FLOWINFO:
1261 		val = np->rxopt.bits.rxflow;
1262 		break;
1263 
1264 	case IPV6_RECVPATHMTU:
1265 		val = np->rxopt.bits.rxpmtu;
1266 		break;
1267 
1268 	case IPV6_PATHMTU:
1269 	{
1270 		struct dst_entry *dst;
1271 		struct ip6_mtuinfo mtuinfo;
1272 
1273 		if (len < sizeof(mtuinfo))
1274 			return -EINVAL;
1275 
1276 		len = sizeof(mtuinfo);
1277 		memset(&mtuinfo, 0, sizeof(mtuinfo));
1278 
1279 		rcu_read_lock();
1280 		dst = __sk_dst_get(sk);
1281 		if (dst)
1282 			mtuinfo.ip6m_mtu = dst_mtu(dst);
1283 		rcu_read_unlock();
1284 		if (!mtuinfo.ip6m_mtu)
1285 			return -ENOTCONN;
1286 
1287 		if (copy_to_sockptr(optlen, &len, sizeof(int)))
1288 			return -EFAULT;
1289 		if (copy_to_sockptr(optval, &mtuinfo, len))
1290 			return -EFAULT;
1291 
1292 		return 0;
1293 	}
1294 
1295 	case IPV6_TRANSPARENT:
1296 		val = inet_test_bit(TRANSPARENT, sk);
1297 		break;
1298 
1299 	case IPV6_FREEBIND:
1300 		val = inet_test_bit(FREEBIND, sk);
1301 		break;
1302 
1303 	case IPV6_RECVORIGDSTADDR:
1304 		val = np->rxopt.bits.rxorigdstaddr;
1305 		break;
1306 
1307 	case IPV6_UNICAST_HOPS:
1308 	case IPV6_MULTICAST_HOPS:
1309 	{
1310 		struct dst_entry *dst;
1311 
1312 		if (optname == IPV6_UNICAST_HOPS)
1313 			val = READ_ONCE(np->hop_limit);
1314 		else
1315 			val = READ_ONCE(np->mcast_hops);
1316 
1317 		if (val < 0) {
1318 			rcu_read_lock();
1319 			dst = __sk_dst_get(sk);
1320 			if (dst)
1321 				val = ip6_dst_hoplimit(dst);
1322 			rcu_read_unlock();
1323 		}
1324 
1325 		if (val < 0)
1326 			val = READ_ONCE(sock_net(sk)->ipv6.devconf_all->hop_limit);
1327 		break;
1328 	}
1329 
1330 	case IPV6_MULTICAST_LOOP:
1331 		val = inet6_test_bit(MC6_LOOP, sk);
1332 		break;
1333 
1334 	case IPV6_MULTICAST_IF:
1335 		val = READ_ONCE(np->mcast_oif);
1336 		break;
1337 
1338 	case IPV6_MULTICAST_ALL:
1339 		val = inet6_test_bit(MC6_ALL, sk);
1340 		break;
1341 
1342 	case IPV6_UNICAST_IF:
1343 		val = (__force int)htonl((__u32) READ_ONCE(np->ucast_oif));
1344 		break;
1345 
1346 	case IPV6_MTU_DISCOVER:
1347 		val = READ_ONCE(np->pmtudisc);
1348 		break;
1349 
1350 	case IPV6_RECVERR:
1351 		val = inet6_test_bit(RECVERR6, sk);
1352 		break;
1353 
1354 	case IPV6_FLOWINFO_SEND:
1355 		val = inet6_test_bit(SNDFLOW, sk);
1356 		break;
1357 
1358 	case IPV6_FLOWLABEL_MGR:
1359 	{
1360 		struct in6_flowlabel_req freq;
1361 		int flags;
1362 
1363 		if (len < sizeof(freq))
1364 			return -EINVAL;
1365 
1366 		if (copy_from_sockptr(&freq, optval, sizeof(freq)))
1367 			return -EFAULT;
1368 
1369 		if (freq.flr_action != IPV6_FL_A_GET)
1370 			return -EINVAL;
1371 
1372 		len = sizeof(freq);
1373 		flags = freq.flr_flags;
1374 
1375 		memset(&freq, 0, sizeof(freq));
1376 
1377 		val = ipv6_flowlabel_opt_get(sk, &freq, flags);
1378 		if (val < 0)
1379 			return val;
1380 
1381 		if (copy_to_sockptr(optlen, &len, sizeof(int)))
1382 			return -EFAULT;
1383 		if (copy_to_sockptr(optval, &freq, len))
1384 			return -EFAULT;
1385 
1386 		return 0;
1387 	}
1388 
1389 	case IPV6_ADDR_PREFERENCES:
1390 		{
1391 		u8 srcprefs = READ_ONCE(np->srcprefs);
1392 		val = 0;
1393 
1394 		if (srcprefs & IPV6_PREFER_SRC_TMP)
1395 			val |= IPV6_PREFER_SRC_TMP;
1396 		else if (srcprefs & IPV6_PREFER_SRC_PUBLIC)
1397 			val |= IPV6_PREFER_SRC_PUBLIC;
1398 		else {
1399 			/* XXX: should we return system default? */
1400 			val |= IPV6_PREFER_SRC_PUBTMP_DEFAULT;
1401 		}
1402 
1403 		if (srcprefs & IPV6_PREFER_SRC_COA)
1404 			val |= IPV6_PREFER_SRC_COA;
1405 		else
1406 			val |= IPV6_PREFER_SRC_HOME;
1407 		break;
1408 		}
1409 	case IPV6_MINHOPCOUNT:
1410 		val = READ_ONCE(np->min_hopcount);
1411 		break;
1412 
1413 	case IPV6_DONTFRAG:
1414 		val = inet6_test_bit(DONTFRAG, sk);
1415 		break;
1416 
1417 	case IPV6_AUTOFLOWLABEL:
1418 		val = ip6_autoflowlabel(sock_net(sk), sk);
1419 		break;
1420 
1421 	case IPV6_RECVFRAGSIZE:
1422 		val = np->rxopt.bits.recvfragsize;
1423 		break;
1424 
1425 	case IPV6_ROUTER_ALERT:
1426 		val = inet6_test_bit(RTALERT, sk);
1427 		break;
1428 
1429 	case IPV6_ROUTER_ALERT_ISOLATE:
1430 		val = inet6_test_bit(RTALERT_ISOLATE, sk);
1431 		break;
1432 
1433 	case IPV6_RECVERR_RFC4884:
1434 		val = inet6_test_bit(RECVERR6_RFC4884, sk);
1435 		break;
1436 
1437 	default:
1438 		return -ENOPROTOOPT;
1439 	}
1440 	len = min_t(unsigned int, sizeof(int), len);
1441 	if (copy_to_sockptr(optlen, &len, sizeof(int)))
1442 		return -EFAULT;
1443 	if (copy_to_sockptr(optval, &val, len))
1444 		return -EFAULT;
1445 	return 0;
1446 }
1447 
ipv6_getsockopt(struct sock * sk,int level,int optname,char __user * optval,int __user * optlen)1448 int ipv6_getsockopt(struct sock *sk, int level, int optname,
1449 		    char __user *optval, int __user *optlen)
1450 {
1451 	int err;
1452 
1453 	if (level == SOL_IP && sk->sk_type != SOCK_RAW)
1454 		return ip_getsockopt(sk, level, optname, optval, optlen);
1455 
1456 	if (level != SOL_IPV6)
1457 		return -ENOPROTOOPT;
1458 
1459 	err = do_ipv6_getsockopt(sk, level, optname,
1460 				 USER_SOCKPTR(optval), USER_SOCKPTR(optlen));
1461 #ifdef CONFIG_NETFILTER
1462 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1463 	if (err == -ENOPROTOOPT && optname != IPV6_2292PKTOPTIONS) {
1464 		int len;
1465 
1466 		if (get_user(len, optlen))
1467 			return -EFAULT;
1468 
1469 		err = nf_getsockopt(sk, PF_INET6, optname, optval, &len);
1470 		if (err >= 0)
1471 			err = put_user(len, optlen);
1472 	}
1473 #endif
1474 	return err;
1475 }
1476 EXPORT_SYMBOL(ipv6_getsockopt);
1477