Linux Audio

Check our new training course

Loading...
v6.9.4
   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
  55struct ip6_ra_chain *ip6_ra_chain;
  56DEFINE_RWLOCK(ip6_ra_lock);
  57
  58DEFINE_STATIC_KEY_FALSE(ip6_min_hopcount);
  59
  60int 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
 102struct ipv6_txoptions *ipv6_update_options(struct sock *sk,
 103					   struct ipv6_txoptions *opt)
 104{
 105	if (inet_test_bit(IS_ICSK, sk)) {
 106		if (opt &&
 107		    !((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) &&
 108		    inet_sk(sk)->inet_daddr != LOOPBACK4_IPV6) {
 109			struct inet_connection_sock *icsk = inet_csk(sk);
 110			icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen;
 111			icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
 112		}
 113	}
 114	opt = xchg((__force struct ipv6_txoptions **)&inet6_sk(sk)->opt,
 115		   opt);
 116	sk_dst_reset(sk);
 117
 118	return opt;
 119}
 120
 121static 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
 141static 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
 164static 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
 205static 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(sock_net(sk)->core.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);
 231out_free_gsf:
 232	kfree(gsf);
 233	return ret;
 234}
 235
 236static 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(sock_net(sk)->core.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
 275out_free_p:
 276	kfree(p);
 277	return ret;
 278}
 279
 280static 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
 300static 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
 320static int ipv6_set_opt_hdr(struct sock *sk, int optname, sockptr_t optval,
 321		int optlen)
 322{
 323	struct ipv6_pinfo *np = inet6_sk(sk);
 324	struct ipv6_opt_hdr *new = NULL;
 325	struct net *net = sock_net(sk);
 326	struct ipv6_txoptions *opt;
 327	int err;
 328
 329	/* hop-by-hop / destination options are privileged option */
 330	if (optname != IPV6_RTHDR && !sockopt_ns_capable(net->user_ns, CAP_NET_RAW))
 331		return -EPERM;
 332
 333	/* remove any sticky options header with a zero option
 334	 * length, per RFC3542.
 335	 */
 336	if (optlen > 0) {
 337		if (sockptr_is_null(optval))
 338			return -EINVAL;
 339		if (optlen < sizeof(struct ipv6_opt_hdr) ||
 340		    optlen & 0x7 ||
 341		    optlen > 8 * 255)
 342			return -EINVAL;
 343
 344		new = memdup_sockptr(optval, optlen);
 345		if (IS_ERR(new))
 346			return PTR_ERR(new);
 347		if (unlikely(ipv6_optlen(new) > optlen)) {
 348			kfree(new);
 349			return -EINVAL;
 350		}
 351	}
 352
 353	opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
 354	opt = ipv6_renew_options(sk, opt, optname, new);
 355	kfree(new);
 356	if (IS_ERR(opt))
 357		return PTR_ERR(opt);
 358
 359	/* routing header option needs extra check */
 360	err = -EINVAL;
 361	if (optname == IPV6_RTHDR && opt && opt->srcrt) {
 362		struct ipv6_rt_hdr *rthdr = opt->srcrt;
 363		switch (rthdr->type) {
 364#if IS_ENABLED(CONFIG_IPV6_MIP6)
 365		case IPV6_SRCRT_TYPE_2:
 366			if (rthdr->hdrlen != 2 || rthdr->segments_left != 1)
 367				goto sticky_done;
 368			break;
 369#endif
 370		case IPV6_SRCRT_TYPE_4:
 371		{
 372			struct ipv6_sr_hdr *srh =
 373				(struct ipv6_sr_hdr *)opt->srcrt;
 374
 375			if (!seg6_validate_srh(srh, optlen, false))
 376				goto sticky_done;
 377			break;
 378		}
 379		default:
 380			goto sticky_done;
 381		}
 382	}
 383
 384	err = 0;
 385	opt = ipv6_update_options(sk, opt);
 386sticky_done:
 387	if (opt) {
 388		atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
 389		txopt_put(opt);
 390	}
 391	return err;
 392}
 393
 394int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
 395		       sockptr_t optval, unsigned int optlen)
 396{
 397	struct ipv6_pinfo *np = inet6_sk(sk);
 398	struct net *net = sock_net(sk);
 399	int val, valbool;
 400	int retv = -ENOPROTOOPT;
 401	bool needs_rtnl = setsockopt_needs_rtnl(optname);
 402
 403	if (sockptr_is_null(optval))
 404		val = 0;
 405	else {
 406		if (optlen >= sizeof(int)) {
 407			if (copy_from_sockptr(&val, optval, sizeof(val)))
 408				return -EFAULT;
 409		} else
 410			val = 0;
 411	}
 412
 413	valbool = (val != 0);
 414
 415	if (ip6_mroute_opt(optname))
 416		return ip6_mroute_setsockopt(sk, optname, optval, optlen);
 417
 418	/* Handle options that can be set without locking the socket. */
 419	switch (optname) {
 420	case IPV6_UNICAST_HOPS:
 421		if (optlen < sizeof(int))
 422			return -EINVAL;
 423		if (val > 255 || val < -1)
 424			return -EINVAL;
 425		WRITE_ONCE(np->hop_limit, val);
 426		return 0;
 427	case IPV6_MULTICAST_LOOP:
 428		if (optlen < sizeof(int))
 429			return -EINVAL;
 430		if (val != valbool)
 431			return -EINVAL;
 432		inet6_assign_bit(MC6_LOOP, sk, valbool);
 433		return 0;
 434	case IPV6_MULTICAST_HOPS:
 435		if (sk->sk_type == SOCK_STREAM)
 436			return retv;
 437		if (optlen < sizeof(int))
 438			return -EINVAL;
 439		if (val > 255 || val < -1)
 440			return -EINVAL;
 441		WRITE_ONCE(np->mcast_hops,
 442			   val == -1 ? IPV6_DEFAULT_MCASTHOPS : val);
 443		return 0;
 444	case IPV6_MTU:
 445		if (optlen < sizeof(int))
 446			return -EINVAL;
 447		if (val && val < IPV6_MIN_MTU)
 448			return -EINVAL;
 449		WRITE_ONCE(np->frag_size, val);
 450		return 0;
 451	case IPV6_MINHOPCOUNT:
 452		if (optlen < sizeof(int))
 453			return -EINVAL;
 454		if (val < 0 || val > 255)
 455			return -EINVAL;
 456
 457		if (val)
 458			static_branch_enable(&ip6_min_hopcount);
 459
 460		/* tcp_v6_err() and tcp_v6_rcv() might read min_hopcount
 461		 * while we are changing it.
 462		 */
 463		WRITE_ONCE(np->min_hopcount, val);
 464		return 0;
 465	case IPV6_RECVERR_RFC4884:
 466		if (optlen < sizeof(int))
 467			return -EINVAL;
 468		if (val < 0 || val > 1)
 469			return -EINVAL;
 470		inet6_assign_bit(RECVERR6_RFC4884, sk, valbool);
 471		return 0;
 472	case IPV6_MULTICAST_ALL:
 473		if (optlen < sizeof(int))
 474			return -EINVAL;
 475		inet6_assign_bit(MC6_ALL, sk, valbool);
 476		return 0;
 477	case IPV6_AUTOFLOWLABEL:
 478		inet6_assign_bit(AUTOFLOWLABEL, sk, valbool);
 479		inet6_set_bit(AUTOFLOWLABEL_SET, sk);
 480		return 0;
 481	case IPV6_DONTFRAG:
 482		inet6_assign_bit(DONTFRAG, sk, valbool);
 483		return 0;
 484	case IPV6_RECVERR:
 485		if (optlen < sizeof(int))
 486			return -EINVAL;
 487		inet6_assign_bit(RECVERR6, sk, valbool);
 488		if (!val)
 489			skb_errqueue_purge(&sk->sk_error_queue);
 490		return 0;
 491	case IPV6_ROUTER_ALERT_ISOLATE:
 492		if (optlen < sizeof(int))
 493			return -EINVAL;
 494		inet6_assign_bit(RTALERT_ISOLATE, sk, valbool);
 495		return 0;
 496	case IPV6_MTU_DISCOVER:
 497		if (optlen < sizeof(int))
 498			return -EINVAL;
 499		if (val < IPV6_PMTUDISC_DONT || val > IPV6_PMTUDISC_OMIT)
 500			return -EINVAL;
 501		WRITE_ONCE(np->pmtudisc, val);
 502		return 0;
 503	case IPV6_FLOWINFO_SEND:
 504		if (optlen < sizeof(int))
 505			return -EINVAL;
 506		inet6_assign_bit(SNDFLOW, sk, valbool);
 507		return 0;
 508	case IPV6_ADDR_PREFERENCES:
 509		if (optlen < sizeof(int))
 510			return -EINVAL;
 511		return ip6_sock_set_addr_preferences(sk, val);
 512	case IPV6_MULTICAST_IF:
 513		if (sk->sk_type == SOCK_STREAM)
 514			return -ENOPROTOOPT;
 515		if (optlen < sizeof(int))
 516			return -EINVAL;
 517		if (val) {
 518			struct net_device *dev;
 519			int bound_dev_if, midx;
 520
 521			rcu_read_lock();
 522
 523			dev = dev_get_by_index_rcu(net, val);
 524			if (!dev) {
 525				rcu_read_unlock();
 526				return -ENODEV;
 527			}
 528			midx = l3mdev_master_ifindex_rcu(dev);
 529
 530			rcu_read_unlock();
 531
 532			bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
 533			if (bound_dev_if &&
 534			    bound_dev_if != val &&
 535			    (!midx || midx != bound_dev_if))
 536				return -EINVAL;
 537		}
 538		WRITE_ONCE(np->mcast_oif, val);
 539		return 0;
 540	case IPV6_UNICAST_IF:
 541	{
 542		struct net_device *dev;
 543		int ifindex;
 544
 545		if (optlen != sizeof(int))
 546			return -EINVAL;
 547
 548		ifindex = (__force int)ntohl((__force __be32)val);
 549		if (!ifindex) {
 550			WRITE_ONCE(np->ucast_oif, 0);
 551			return 0;
 552		}
 553
 554		dev = dev_get_by_index(net, ifindex);
 555		if (!dev)
 556			return -EADDRNOTAVAIL;
 557		dev_put(dev);
 558
 559		if (READ_ONCE(sk->sk_bound_dev_if))
 560			return -EINVAL;
 561
 562		WRITE_ONCE(np->ucast_oif, ifindex);
 563		return 0;
 564	}
 565	}
 566	if (needs_rtnl)
 567		rtnl_lock();
 568	sockopt_lock_sock(sk);
 569
 570	/* Another thread has converted the socket into IPv4 with
 571	 * IPV6_ADDRFORM concurrently.
 572	 */
 573	if (unlikely(sk->sk_family != AF_INET6))
 574		goto unlock;
 575
 576	switch (optname) {
 577
 578	case IPV6_ADDRFORM:
 579		if (optlen < sizeof(int))
 580			goto e_inval;
 581		if (val == PF_INET) {
 582			if (sk->sk_type == SOCK_RAW)
 583				break;
 584
 585			if (sk->sk_protocol == IPPROTO_UDP ||
 586			    sk->sk_protocol == IPPROTO_UDPLITE) {
 587				struct udp_sock *up = udp_sk(sk);
 588				if (up->pending == AF_INET6) {
 589					retv = -EBUSY;
 590					break;
 591				}
 592			} else if (sk->sk_protocol == IPPROTO_TCP) {
 593				if (sk->sk_prot != &tcpv6_prot) {
 594					retv = -EBUSY;
 595					break;
 596				}
 597			} else {
 598				break;
 599			}
 600
 601			if (sk->sk_state != TCP_ESTABLISHED) {
 602				retv = -ENOTCONN;
 603				break;
 604			}
 605
 606			if (ipv6_only_sock(sk) ||
 607			    !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) {
 608				retv = -EADDRNOTAVAIL;
 609				break;
 610			}
 611
 612			__ipv6_sock_mc_close(sk);
 613			__ipv6_sock_ac_close(sk);
 614
 615			if (sk->sk_protocol == IPPROTO_TCP) {
 616				struct inet_connection_sock *icsk = inet_csk(sk);
 617
 618				sock_prot_inuse_add(net, sk->sk_prot, -1);
 619				sock_prot_inuse_add(net, &tcp_prot, 1);
 620
 621				/* Paired with READ_ONCE(sk->sk_prot) in inet6_stream_ops */
 622				WRITE_ONCE(sk->sk_prot, &tcp_prot);
 623				/* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
 624				WRITE_ONCE(icsk->icsk_af_ops, &ipv4_specific);
 625				WRITE_ONCE(sk->sk_socket->ops, &inet_stream_ops);
 626				WRITE_ONCE(sk->sk_family, PF_INET);
 627				tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
 628			} else {
 629				struct proto *prot = &udp_prot;
 630
 631				if (sk->sk_protocol == IPPROTO_UDPLITE)
 632					prot = &udplite_prot;
 633
 634				sock_prot_inuse_add(net, sk->sk_prot, -1);
 635				sock_prot_inuse_add(net, prot, 1);
 636
 637				/* Paired with READ_ONCE(sk->sk_prot) in inet6_dgram_ops */
 638				WRITE_ONCE(sk->sk_prot, prot);
 639				WRITE_ONCE(sk->sk_socket->ops, &inet_dgram_ops);
 640				WRITE_ONCE(sk->sk_family, PF_INET);
 641			}
 642
 643			/* Disable all options not to allocate memory anymore,
 644			 * but there is still a race.  See the lockless path
 645			 * in udpv6_sendmsg() and ipv6_local_rxpmtu().
 646			 */
 647			np->rxopt.all = 0;
 648
 649			inet6_cleanup_sock(sk);
 650
 651			module_put(THIS_MODULE);
 652			retv = 0;
 653			break;
 654		}
 655		goto e_inval;
 656
 657	case IPV6_V6ONLY:
 658		if (optlen < sizeof(int) ||
 659		    inet_sk(sk)->inet_num)
 660			goto e_inval;
 661		sk->sk_ipv6only = valbool;
 662		retv = 0;
 663		break;
 664
 665	case IPV6_RECVPKTINFO:
 666		if (optlen < sizeof(int))
 667			goto e_inval;
 668		np->rxopt.bits.rxinfo = valbool;
 669		retv = 0;
 670		break;
 671
 672	case IPV6_2292PKTINFO:
 673		if (optlen < sizeof(int))
 674			goto e_inval;
 675		np->rxopt.bits.rxoinfo = valbool;
 676		retv = 0;
 677		break;
 678
 679	case IPV6_RECVHOPLIMIT:
 680		if (optlen < sizeof(int))
 681			goto e_inval;
 682		np->rxopt.bits.rxhlim = valbool;
 683		retv = 0;
 684		break;
 685
 686	case IPV6_2292HOPLIMIT:
 687		if (optlen < sizeof(int))
 688			goto e_inval;
 689		np->rxopt.bits.rxohlim = valbool;
 690		retv = 0;
 691		break;
 692
 693	case IPV6_RECVRTHDR:
 694		if (optlen < sizeof(int))
 695			goto e_inval;
 696		np->rxopt.bits.srcrt = valbool;
 697		retv = 0;
 698		break;
 699
 700	case IPV6_2292RTHDR:
 701		if (optlen < sizeof(int))
 702			goto e_inval;
 703		np->rxopt.bits.osrcrt = valbool;
 704		retv = 0;
 705		break;
 706
 707	case IPV6_RECVHOPOPTS:
 708		if (optlen < sizeof(int))
 709			goto e_inval;
 710		np->rxopt.bits.hopopts = valbool;
 711		retv = 0;
 712		break;
 713
 714	case IPV6_2292HOPOPTS:
 715		if (optlen < sizeof(int))
 716			goto e_inval;
 717		np->rxopt.bits.ohopopts = valbool;
 718		retv = 0;
 719		break;
 720
 721	case IPV6_RECVDSTOPTS:
 722		if (optlen < sizeof(int))
 723			goto e_inval;
 724		np->rxopt.bits.dstopts = valbool;
 725		retv = 0;
 726		break;
 727
 728	case IPV6_2292DSTOPTS:
 729		if (optlen < sizeof(int))
 730			goto e_inval;
 731		np->rxopt.bits.odstopts = valbool;
 732		retv = 0;
 733		break;
 734
 735	case IPV6_TCLASS:
 736		if (optlen < sizeof(int))
 737			goto e_inval;
 738		if (val < -1 || val > 0xff)
 739			goto e_inval;
 740		/* RFC 3542, 6.5: default traffic class of 0x0 */
 741		if (val == -1)
 742			val = 0;
 743		if (sk->sk_type == SOCK_STREAM) {
 744			val &= ~INET_ECN_MASK;
 745			val |= np->tclass & INET_ECN_MASK;
 746		}
 747		if (np->tclass != val) {
 748			np->tclass = val;
 749			sk_dst_reset(sk);
 750		}
 751		retv = 0;
 752		break;
 753
 754	case IPV6_RECVTCLASS:
 755		if (optlen < sizeof(int))
 756			goto e_inval;
 757		np->rxopt.bits.rxtclass = valbool;
 758		retv = 0;
 759		break;
 760
 761	case IPV6_FLOWINFO:
 762		if (optlen < sizeof(int))
 763			goto e_inval;
 764		np->rxopt.bits.rxflow = valbool;
 765		retv = 0;
 766		break;
 767
 768	case IPV6_RECVPATHMTU:
 769		if (optlen < sizeof(int))
 770			goto e_inval;
 771		np->rxopt.bits.rxpmtu = valbool;
 772		retv = 0;
 773		break;
 774
 775	case IPV6_TRANSPARENT:
 776		if (valbool && !sockopt_ns_capable(net->user_ns, CAP_NET_RAW) &&
 777		    !sockopt_ns_capable(net->user_ns, CAP_NET_ADMIN)) {
 778			retv = -EPERM;
 779			break;
 780		}
 781		if (optlen < sizeof(int))
 782			goto e_inval;
 783		/* we don't have a separate transparent bit for IPV6 we use the one in the IPv4 socket */
 784		inet_assign_bit(TRANSPARENT, sk, valbool);
 785		retv = 0;
 786		break;
 787
 788	case IPV6_FREEBIND:
 789		if (optlen < sizeof(int))
 790			goto e_inval;
 791		/* we also don't have a separate freebind bit for IPV6 */
 792		inet_assign_bit(FREEBIND, sk, valbool);
 793		retv = 0;
 794		break;
 795
 796	case IPV6_RECVORIGDSTADDR:
 797		if (optlen < sizeof(int))
 798			goto e_inval;
 799		np->rxopt.bits.rxorigdstaddr = valbool;
 800		retv = 0;
 801		break;
 802
 803	case IPV6_HOPOPTS:
 804	case IPV6_RTHDRDSTOPTS:
 805	case IPV6_RTHDR:
 806	case IPV6_DSTOPTS:
 807		retv = ipv6_set_opt_hdr(sk, optname, optval, optlen);
 808		break;
 809
 810	case IPV6_PKTINFO:
 811	{
 812		struct in6_pktinfo pkt;
 813
 814		if (optlen == 0)
 815			goto e_inval;
 816		else if (optlen < sizeof(struct in6_pktinfo) ||
 817			 sockptr_is_null(optval))
 818			goto e_inval;
 819
 820		if (copy_from_sockptr(&pkt, optval, sizeof(pkt))) {
 821			retv = -EFAULT;
 822			break;
 823		}
 824		if (!sk_dev_equal_l3scope(sk, pkt.ipi6_ifindex))
 825			goto e_inval;
 826
 827		np->sticky_pktinfo.ipi6_ifindex = pkt.ipi6_ifindex;
 828		np->sticky_pktinfo.ipi6_addr = pkt.ipi6_addr;
 829		retv = 0;
 830		break;
 831	}
 832
 833	case IPV6_2292PKTOPTIONS:
 834	{
 835		struct ipv6_txoptions *opt = NULL;
 836		struct msghdr msg;
 837		struct flowi6 fl6;
 838		struct ipcm6_cookie ipc6;
 839
 840		memset(&fl6, 0, sizeof(fl6));
 841		fl6.flowi6_oif = sk->sk_bound_dev_if;
 842		fl6.flowi6_mark = sk->sk_mark;
 843
 844		if (optlen == 0)
 845			goto update;
 846
 847		/* 1K is probably excessive
 848		 * 1K is surely not enough, 2K per standard header is 16K.
 849		 */
 850		retv = -EINVAL;
 851		if (optlen > 64*1024)
 852			break;
 853
 854		opt = sock_kmalloc(sk, sizeof(*opt) + optlen, GFP_KERNEL);
 855		retv = -ENOBUFS;
 856		if (!opt)
 857			break;
 858
 859		memset(opt, 0, sizeof(*opt));
 860		refcount_set(&opt->refcnt, 1);
 861		opt->tot_len = sizeof(*opt) + optlen;
 862		retv = -EFAULT;
 863		if (copy_from_sockptr(opt + 1, optval, optlen))
 864			goto done;
 865
 866		msg.msg_controllen = optlen;
 867		msg.msg_control_is_user = false;
 868		msg.msg_control = (void *)(opt+1);
 869		ipc6.opt = opt;
 870
 871		retv = ip6_datagram_send_ctl(net, sk, &msg, &fl6, &ipc6);
 872		if (retv)
 873			goto done;
 874update:
 875		retv = 0;
 876		opt = ipv6_update_options(sk, opt);
 877done:
 878		if (opt) {
 879			atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
 880			txopt_put(opt);
 881		}
 882		break;
 883	}
 884
 885	case IPV6_ADD_MEMBERSHIP:
 886	case IPV6_DROP_MEMBERSHIP:
 887	{
 888		struct ipv6_mreq mreq;
 889
 890		if (optlen < sizeof(struct ipv6_mreq))
 891			goto e_inval;
 892
 893		retv = -EPROTO;
 894		if (inet_test_bit(IS_ICSK, sk))
 895			break;
 896
 897		retv = -EFAULT;
 898		if (copy_from_sockptr(&mreq, optval, sizeof(struct ipv6_mreq)))
 899			break;
 900
 901		if (optname == IPV6_ADD_MEMBERSHIP)
 902			retv = ipv6_sock_mc_join(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr);
 903		else
 904			retv = ipv6_sock_mc_drop(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr);
 905		break;
 906	}
 907	case IPV6_JOIN_ANYCAST:
 908	case IPV6_LEAVE_ANYCAST:
 909	{
 910		struct ipv6_mreq mreq;
 911
 912		if (optlen < sizeof(struct ipv6_mreq))
 913			goto e_inval;
 914
 915		retv = -EFAULT;
 916		if (copy_from_sockptr(&mreq, optval, sizeof(struct ipv6_mreq)))
 917			break;
 918
 919		if (optname == IPV6_JOIN_ANYCAST)
 920			retv = ipv6_sock_ac_join(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_acaddr);
 921		else
 922			retv = ipv6_sock_ac_drop(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_acaddr);
 923		break;
 924	}
 925	case MCAST_JOIN_GROUP:
 926	case MCAST_LEAVE_GROUP:
 927		if (in_compat_syscall())
 928			retv = compat_ipv6_mcast_join_leave(sk, optname, optval,
 929							    optlen);
 930		else
 931			retv = ipv6_mcast_join_leave(sk, optname, optval,
 932						     optlen);
 933		break;
 934	case MCAST_JOIN_SOURCE_GROUP:
 935	case MCAST_LEAVE_SOURCE_GROUP:
 936	case MCAST_BLOCK_SOURCE:
 937	case MCAST_UNBLOCK_SOURCE:
 938		retv = do_ipv6_mcast_group_source(sk, optname, optval, optlen);
 939		break;
 940	case MCAST_MSFILTER:
 941		if (in_compat_syscall())
 942			retv = compat_ipv6_set_mcast_msfilter(sk, optval,
 943							      optlen);
 944		else
 945			retv = ipv6_set_mcast_msfilter(sk, optval, optlen);
 946		break;
 947	case IPV6_ROUTER_ALERT:
 948		if (optlen < sizeof(int))
 949			goto e_inval;
 950		retv = ip6_ra_control(sk, val);
 951		if (retv == 0)
 952			inet6_assign_bit(RTALERT, sk, valbool);
 953		break;
 954	case IPV6_FLOWLABEL_MGR:
 955		retv = ipv6_flowlabel_opt(sk, optval, optlen);
 956		break;
 957	case IPV6_IPSEC_POLICY:
 958	case IPV6_XFRM_POLICY:
 959		retv = -EPERM;
 960		if (!sockopt_ns_capable(net->user_ns, CAP_NET_ADMIN))
 961			break;
 962		retv = xfrm_user_policy(sk, optname, optval, optlen);
 963		break;
 964
 965	case IPV6_RECVFRAGSIZE:
 966		np->rxopt.bits.recvfragsize = valbool;
 967		retv = 0;
 968		break;
 969	}
 970
 971unlock:
 972	sockopt_release_sock(sk);
 973	if (needs_rtnl)
 974		rtnl_unlock();
 975
 976	return retv;
 977
 978e_inval:
 979	retv = -EINVAL;
 980	goto unlock;
 981}
 982
 983int ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
 984		    unsigned int optlen)
 985{
 986	int err;
 987
 988	if (level == SOL_IP && sk->sk_type != SOCK_RAW)
 989		return udp_prot.setsockopt(sk, level, optname, optval, optlen);
 990
 991	if (level != SOL_IPV6)
 992		return -ENOPROTOOPT;
 993
 994	err = do_ipv6_setsockopt(sk, level, optname, optval, optlen);
 995#ifdef CONFIG_NETFILTER
 996	/* we need to exclude all possible ENOPROTOOPTs except default case */
 997	if (err == -ENOPROTOOPT && optname != IPV6_IPSEC_POLICY &&
 998			optname != IPV6_XFRM_POLICY)
 999		err = nf_setsockopt(sk, PF_INET6, optname, optval, optlen);
1000#endif
1001	return err;
1002}
1003EXPORT_SYMBOL(ipv6_setsockopt);
1004
1005static int ipv6_getsockopt_sticky(struct sock *sk, struct ipv6_txoptions *opt,
1006				  int optname, sockptr_t optval, int len)
1007{
1008	struct ipv6_opt_hdr *hdr;
1009
1010	if (!opt)
1011		return 0;
1012
1013	switch (optname) {
1014	case IPV6_HOPOPTS:
1015		hdr = opt->hopopt;
1016		break;
1017	case IPV6_RTHDRDSTOPTS:
1018		hdr = opt->dst0opt;
1019		break;
1020	case IPV6_RTHDR:
1021		hdr = (struct ipv6_opt_hdr *)opt->srcrt;
1022		break;
1023	case IPV6_DSTOPTS:
1024		hdr = opt->dst1opt;
1025		break;
1026	default:
1027		return -EINVAL;	/* should not happen */
1028	}
1029
1030	if (!hdr)
1031		return 0;
1032
1033	len = min_t(unsigned int, len, ipv6_optlen(hdr));
1034	if (copy_to_sockptr(optval, hdr, len))
1035		return -EFAULT;
1036	return len;
1037}
1038
1039static int ipv6_get_msfilter(struct sock *sk, sockptr_t optval,
1040			     sockptr_t optlen, int len)
1041{
1042	const int size0 = offsetof(struct group_filter, gf_slist_flex);
1043	struct group_filter gsf;
1044	int num;
1045	int err;
1046
1047	if (len < size0)
1048		return -EINVAL;
1049	if (copy_from_sockptr(&gsf, optval, size0))
1050		return -EFAULT;
1051	if (gsf.gf_group.ss_family != AF_INET6)
1052		return -EADDRNOTAVAIL;
1053	num = gsf.gf_numsrc;
1054	sockopt_lock_sock(sk);
1055	err = ip6_mc_msfget(sk, &gsf, optval, size0);
1056	if (!err) {
1057		if (num > gsf.gf_numsrc)
1058			num = gsf.gf_numsrc;
1059		len = GROUP_FILTER_SIZE(num);
1060		if (copy_to_sockptr(optlen, &len, sizeof(int)) ||
1061		    copy_to_sockptr(optval, &gsf, size0))
1062			err = -EFAULT;
1063	}
1064	sockopt_release_sock(sk);
1065	return err;
1066}
1067
1068static int compat_ipv6_get_msfilter(struct sock *sk, sockptr_t optval,
1069				    sockptr_t optlen, int len)
1070{
1071	const int size0 = offsetof(struct compat_group_filter, gf_slist_flex);
1072	struct compat_group_filter gf32;
1073	struct group_filter gf;
1074	int err;
1075	int num;
1076
1077	if (len < size0)
1078		return -EINVAL;
1079
1080	if (copy_from_sockptr(&gf32, optval, size0))
1081		return -EFAULT;
1082	gf.gf_interface = gf32.gf_interface;
1083	gf.gf_fmode = gf32.gf_fmode;
1084	num = gf.gf_numsrc = gf32.gf_numsrc;
1085	gf.gf_group = gf32.gf_group;
1086
1087	if (gf.gf_group.ss_family != AF_INET6)
1088		return -EADDRNOTAVAIL;
1089
1090	sockopt_lock_sock(sk);
1091	err = ip6_mc_msfget(sk, &gf, optval, size0);
1092	sockopt_release_sock(sk);
1093	if (err)
1094		return err;
1095	if (num > gf.gf_numsrc)
1096		num = gf.gf_numsrc;
1097	len = GROUP_FILTER_SIZE(num) - (sizeof(gf)-sizeof(gf32));
1098	if (copy_to_sockptr(optlen, &len, sizeof(int)) ||
1099	    copy_to_sockptr_offset(optval, offsetof(struct compat_group_filter, gf_fmode),
1100				   &gf.gf_fmode, sizeof(gf32.gf_fmode)) ||
1101	    copy_to_sockptr_offset(optval, offsetof(struct compat_group_filter, gf_numsrc),
1102				   &gf.gf_numsrc, sizeof(gf32.gf_numsrc)))
1103		return -EFAULT;
1104	return 0;
1105}
1106
1107int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
1108		       sockptr_t optval, sockptr_t optlen)
1109{
1110	struct ipv6_pinfo *np = inet6_sk(sk);
1111	int len;
1112	int val;
1113
1114	if (ip6_mroute_opt(optname))
1115		return ip6_mroute_getsockopt(sk, optname, optval, optlen);
1116
1117	if (copy_from_sockptr(&len, optlen, sizeof(int)))
1118		return -EFAULT;
1119	switch (optname) {
1120	case IPV6_ADDRFORM:
1121		if (sk->sk_protocol != IPPROTO_UDP &&
1122		    sk->sk_protocol != IPPROTO_UDPLITE &&
1123		    sk->sk_protocol != IPPROTO_TCP)
1124			return -ENOPROTOOPT;
1125		if (sk->sk_state != TCP_ESTABLISHED)
1126			return -ENOTCONN;
1127		val = sk->sk_family;
1128		break;
1129	case MCAST_MSFILTER:
1130		if (in_compat_syscall())
1131			return compat_ipv6_get_msfilter(sk, optval, optlen, len);
1132		return ipv6_get_msfilter(sk, optval, optlen, len);
1133	case IPV6_2292PKTOPTIONS:
1134	{
1135		struct msghdr msg;
1136		struct sk_buff *skb;
1137
1138		if (sk->sk_type != SOCK_STREAM)
1139			return -ENOPROTOOPT;
1140
1141		if (optval.is_kernel) {
1142			msg.msg_control_is_user = false;
1143			msg.msg_control = optval.kernel;
1144		} else {
1145			msg.msg_control_is_user = true;
1146			msg.msg_control_user = optval.user;
1147		}
1148		msg.msg_controllen = len;
1149		msg.msg_flags = 0;
1150
1151		sockopt_lock_sock(sk);
1152		skb = np->pktoptions;
1153		if (skb)
1154			ip6_datagram_recv_ctl(sk, &msg, skb);
1155		sockopt_release_sock(sk);
1156		if (!skb) {
1157			if (np->rxopt.bits.rxinfo) {
1158				int mcast_oif = READ_ONCE(np->mcast_oif);
1159				struct in6_pktinfo src_info;
1160
1161				src_info.ipi6_ifindex = mcast_oif ? :
1162					np->sticky_pktinfo.ipi6_ifindex;
1163				src_info.ipi6_addr = mcast_oif ? sk->sk_v6_daddr : np->sticky_pktinfo.ipi6_addr;
1164				put_cmsg(&msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
1165			}
1166			if (np->rxopt.bits.rxhlim) {
1167				int hlim = READ_ONCE(np->mcast_hops);
1168
1169				put_cmsg(&msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
1170			}
1171			if (np->rxopt.bits.rxtclass) {
1172				int tclass = (int)ip6_tclass(np->rcv_flowinfo);
1173
1174				put_cmsg(&msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
1175			}
1176			if (np->rxopt.bits.rxoinfo) {
1177				int mcast_oif = READ_ONCE(np->mcast_oif);
1178				struct in6_pktinfo src_info;
1179
1180				src_info.ipi6_ifindex = mcast_oif ? :
1181					np->sticky_pktinfo.ipi6_ifindex;
1182				src_info.ipi6_addr = mcast_oif ? sk->sk_v6_daddr :
1183								 np->sticky_pktinfo.ipi6_addr;
1184				put_cmsg(&msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
1185			}
1186			if (np->rxopt.bits.rxohlim) {
1187				int hlim = READ_ONCE(np->mcast_hops);
1188
1189				put_cmsg(&msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
1190			}
1191			if (np->rxopt.bits.rxflow) {
1192				__be32 flowinfo = np->rcv_flowinfo;
1193
1194				put_cmsg(&msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
1195			}
1196		}
1197		len -= msg.msg_controllen;
1198		return copy_to_sockptr(optlen, &len, sizeof(int));
1199	}
1200	case IPV6_MTU:
1201	{
1202		struct dst_entry *dst;
1203
1204		val = 0;
1205		rcu_read_lock();
1206		dst = __sk_dst_get(sk);
1207		if (dst)
1208			val = dst_mtu(dst);
1209		rcu_read_unlock();
1210		if (!val)
1211			return -ENOTCONN;
1212		break;
1213	}
1214
1215	case IPV6_V6ONLY:
1216		val = sk->sk_ipv6only;
1217		break;
1218
1219	case IPV6_RECVPKTINFO:
1220		val = np->rxopt.bits.rxinfo;
1221		break;
1222
1223	case IPV6_2292PKTINFO:
1224		val = np->rxopt.bits.rxoinfo;
1225		break;
1226
1227	case IPV6_RECVHOPLIMIT:
1228		val = np->rxopt.bits.rxhlim;
1229		break;
1230
1231	case IPV6_2292HOPLIMIT:
1232		val = np->rxopt.bits.rxohlim;
1233		break;
1234
1235	case IPV6_RECVRTHDR:
1236		val = np->rxopt.bits.srcrt;
1237		break;
1238
1239	case IPV6_2292RTHDR:
1240		val = np->rxopt.bits.osrcrt;
1241		break;
1242
1243	case IPV6_HOPOPTS:
1244	case IPV6_RTHDRDSTOPTS:
1245	case IPV6_RTHDR:
1246	case IPV6_DSTOPTS:
1247	{
1248		struct ipv6_txoptions *opt;
1249
1250		sockopt_lock_sock(sk);
1251		opt = rcu_dereference_protected(np->opt,
1252						lockdep_sock_is_held(sk));
1253		len = ipv6_getsockopt_sticky(sk, opt, optname, optval, len);
1254		sockopt_release_sock(sk);
1255		/* check if ipv6_getsockopt_sticky() returns err code */
1256		if (len < 0)
1257			return len;
1258		return copy_to_sockptr(optlen, &len, sizeof(int));
1259	}
1260
1261	case IPV6_RECVHOPOPTS:
1262		val = np->rxopt.bits.hopopts;
1263		break;
1264
1265	case IPV6_2292HOPOPTS:
1266		val = np->rxopt.bits.ohopopts;
1267		break;
1268
1269	case IPV6_RECVDSTOPTS:
1270		val = np->rxopt.bits.dstopts;
1271		break;
1272
1273	case IPV6_2292DSTOPTS:
1274		val = np->rxopt.bits.odstopts;
1275		break;
1276
1277	case IPV6_TCLASS:
1278		val = np->tclass;
1279		break;
1280
1281	case IPV6_RECVTCLASS:
1282		val = np->rxopt.bits.rxtclass;
1283		break;
1284
1285	case IPV6_FLOWINFO:
1286		val = np->rxopt.bits.rxflow;
1287		break;
1288
1289	case IPV6_RECVPATHMTU:
1290		val = np->rxopt.bits.rxpmtu;
1291		break;
1292
1293	case IPV6_PATHMTU:
1294	{
1295		struct dst_entry *dst;
1296		struct ip6_mtuinfo mtuinfo;
1297
1298		if (len < sizeof(mtuinfo))
1299			return -EINVAL;
1300
1301		len = sizeof(mtuinfo);
1302		memset(&mtuinfo, 0, sizeof(mtuinfo));
1303
1304		rcu_read_lock();
1305		dst = __sk_dst_get(sk);
1306		if (dst)
1307			mtuinfo.ip6m_mtu = dst_mtu(dst);
1308		rcu_read_unlock();
1309		if (!mtuinfo.ip6m_mtu)
1310			return -ENOTCONN;
1311
1312		if (copy_to_sockptr(optlen, &len, sizeof(int)))
1313			return -EFAULT;
1314		if (copy_to_sockptr(optval, &mtuinfo, len))
1315			return -EFAULT;
1316
1317		return 0;
1318	}
1319
1320	case IPV6_TRANSPARENT:
1321		val = inet_test_bit(TRANSPARENT, sk);
1322		break;
1323
1324	case IPV6_FREEBIND:
1325		val = inet_test_bit(FREEBIND, sk);
1326		break;
1327
1328	case IPV6_RECVORIGDSTADDR:
1329		val = np->rxopt.bits.rxorigdstaddr;
1330		break;
1331
1332	case IPV6_UNICAST_HOPS:
1333	case IPV6_MULTICAST_HOPS:
1334	{
1335		struct dst_entry *dst;
1336
1337		if (optname == IPV6_UNICAST_HOPS)
1338			val = READ_ONCE(np->hop_limit);
1339		else
1340			val = READ_ONCE(np->mcast_hops);
1341
1342		if (val < 0) {
1343			rcu_read_lock();
1344			dst = __sk_dst_get(sk);
1345			if (dst)
1346				val = ip6_dst_hoplimit(dst);
1347			rcu_read_unlock();
1348		}
1349
1350		if (val < 0)
1351			val = READ_ONCE(sock_net(sk)->ipv6.devconf_all->hop_limit);
1352		break;
1353	}
1354
1355	case IPV6_MULTICAST_LOOP:
1356		val = inet6_test_bit(MC6_LOOP, sk);
1357		break;
1358
1359	case IPV6_MULTICAST_IF:
1360		val = READ_ONCE(np->mcast_oif);
1361		break;
1362
1363	case IPV6_MULTICAST_ALL:
1364		val = inet6_test_bit(MC6_ALL, sk);
1365		break;
1366
1367	case IPV6_UNICAST_IF:
1368		val = (__force int)htonl((__u32) READ_ONCE(np->ucast_oif));
1369		break;
1370
1371	case IPV6_MTU_DISCOVER:
1372		val = READ_ONCE(np->pmtudisc);
1373		break;
1374
1375	case IPV6_RECVERR:
1376		val = inet6_test_bit(RECVERR6, sk);
1377		break;
1378
1379	case IPV6_FLOWINFO_SEND:
1380		val = inet6_test_bit(SNDFLOW, sk);
1381		break;
1382
1383	case IPV6_FLOWLABEL_MGR:
1384	{
1385		struct in6_flowlabel_req freq;
1386		int flags;
1387
1388		if (len < sizeof(freq))
1389			return -EINVAL;
1390
1391		if (copy_from_sockptr(&freq, optval, sizeof(freq)))
1392			return -EFAULT;
1393
1394		if (freq.flr_action != IPV6_FL_A_GET)
1395			return -EINVAL;
1396
1397		len = sizeof(freq);
1398		flags = freq.flr_flags;
1399
1400		memset(&freq, 0, sizeof(freq));
1401
1402		val = ipv6_flowlabel_opt_get(sk, &freq, flags);
1403		if (val < 0)
1404			return val;
1405
1406		if (copy_to_sockptr(optlen, &len, sizeof(int)))
1407			return -EFAULT;
1408		if (copy_to_sockptr(optval, &freq, len))
1409			return -EFAULT;
1410
1411		return 0;
1412	}
1413
1414	case IPV6_ADDR_PREFERENCES:
1415		{
1416		u8 srcprefs = READ_ONCE(np->srcprefs);
1417		val = 0;
1418
1419		if (srcprefs & IPV6_PREFER_SRC_TMP)
1420			val |= IPV6_PREFER_SRC_TMP;
1421		else if (srcprefs & IPV6_PREFER_SRC_PUBLIC)
1422			val |= IPV6_PREFER_SRC_PUBLIC;
1423		else {
1424			/* XXX: should we return system default? */
1425			val |= IPV6_PREFER_SRC_PUBTMP_DEFAULT;
1426		}
1427
1428		if (srcprefs & IPV6_PREFER_SRC_COA)
1429			val |= IPV6_PREFER_SRC_COA;
1430		else
1431			val |= IPV6_PREFER_SRC_HOME;
1432		break;
1433		}
1434	case IPV6_MINHOPCOUNT:
1435		val = READ_ONCE(np->min_hopcount);
1436		break;
1437
1438	case IPV6_DONTFRAG:
1439		val = inet6_test_bit(DONTFRAG, sk);
1440		break;
1441
1442	case IPV6_AUTOFLOWLABEL:
1443		val = ip6_autoflowlabel(sock_net(sk), sk);
1444		break;
1445
1446	case IPV6_RECVFRAGSIZE:
1447		val = np->rxopt.bits.recvfragsize;
1448		break;
1449
1450	case IPV6_ROUTER_ALERT:
1451		val = inet6_test_bit(RTALERT, sk);
1452		break;
1453
1454	case IPV6_ROUTER_ALERT_ISOLATE:
1455		val = inet6_test_bit(RTALERT_ISOLATE, sk);
1456		break;
1457
1458	case IPV6_RECVERR_RFC4884:
1459		val = inet6_test_bit(RECVERR6_RFC4884, sk);
1460		break;
1461
1462	default:
1463		return -ENOPROTOOPT;
1464	}
1465	len = min_t(unsigned int, sizeof(int), len);
1466	if (copy_to_sockptr(optlen, &len, sizeof(int)))
1467		return -EFAULT;
1468	if (copy_to_sockptr(optval, &val, len))
1469		return -EFAULT;
1470	return 0;
1471}
1472
1473int ipv6_getsockopt(struct sock *sk, int level, int optname,
1474		    char __user *optval, int __user *optlen)
1475{
1476	int err;
1477
1478	if (level == SOL_IP && sk->sk_type != SOCK_RAW)
1479		return udp_prot.getsockopt(sk, level, optname, optval, optlen);
1480
1481	if (level != SOL_IPV6)
1482		return -ENOPROTOOPT;
1483
1484	err = do_ipv6_getsockopt(sk, level, optname,
1485				 USER_SOCKPTR(optval), USER_SOCKPTR(optlen));
1486#ifdef CONFIG_NETFILTER
1487	/* we need to exclude all possible ENOPROTOOPTs except default case */
1488	if (err == -ENOPROTOOPT && optname != IPV6_2292PKTOPTIONS) {
1489		int len;
1490
1491		if (get_user(len, optlen))
1492			return -EFAULT;
1493
1494		err = nf_getsockopt(sk, PF_INET6, optname, optval, &len);
1495		if (err >= 0)
1496			err = put_user(len, optlen);
1497	}
1498#endif
1499	return err;
1500}
1501EXPORT_SYMBOL(ipv6_getsockopt);
v6.13.7
   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
  55struct ip6_ra_chain *ip6_ra_chain;
  56DEFINE_RWLOCK(ip6_ra_lock);
  57
  58DEFINE_STATIC_KEY_FALSE(ip6_min_hopcount);
  59
  60int 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
 102struct 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
 120static bool setsockopt_needs_rtnl(int optname)
 121{
 122	switch (optname) {
 123	case IPV6_ADDRFORM:
 124	case IPV6_ADD_MEMBERSHIP:
 125	case IPV6_DROP_MEMBERSHIP:
 126	case IPV6_JOIN_ANYCAST:
 127	case IPV6_LEAVE_ANYCAST:
 128	case MCAST_JOIN_GROUP:
 129	case MCAST_LEAVE_GROUP:
 130	case MCAST_JOIN_SOURCE_GROUP:
 131	case MCAST_LEAVE_SOURCE_GROUP:
 132	case MCAST_BLOCK_SOURCE:
 133	case MCAST_UNBLOCK_SOURCE:
 134	case MCAST_MSFILTER:
 135		return true;
 136	}
 137	return false;
 138}
 139
 140static int copy_group_source_from_sockptr(struct group_source_req *greqs,
 141		sockptr_t optval, int optlen)
 142{
 143	if (in_compat_syscall()) {
 144		struct compat_group_source_req gr32;
 145
 146		if (optlen < sizeof(gr32))
 147			return -EINVAL;
 148		if (copy_from_sockptr(&gr32, optval, sizeof(gr32)))
 149			return -EFAULT;
 150		greqs->gsr_interface = gr32.gsr_interface;
 151		greqs->gsr_group = gr32.gsr_group;
 152		greqs->gsr_source = gr32.gsr_source;
 153	} else {
 154		if (optlen < sizeof(*greqs))
 155			return -EINVAL;
 156		if (copy_from_sockptr(greqs, optval, sizeof(*greqs)))
 157			return -EFAULT;
 158	}
 159
 160	return 0;
 161}
 162
 163static int do_ipv6_mcast_group_source(struct sock *sk, int optname,
 164		sockptr_t optval, int optlen)
 165{
 166	struct group_source_req greqs;
 167	int omode, add;
 168	int ret;
 169
 170	ret = copy_group_source_from_sockptr(&greqs, optval, optlen);
 171	if (ret)
 172		return ret;
 173
 174	if (greqs.gsr_group.ss_family != AF_INET6 ||
 175	    greqs.gsr_source.ss_family != AF_INET6)
 176		return -EADDRNOTAVAIL;
 177
 178	if (optname == MCAST_BLOCK_SOURCE) {
 179		omode = MCAST_EXCLUDE;
 180		add = 1;
 181	} else if (optname == MCAST_UNBLOCK_SOURCE) {
 182		omode = MCAST_EXCLUDE;
 183		add = 0;
 184	} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
 185		struct sockaddr_in6 *psin6;
 186		int retv;
 187
 188		psin6 = (struct sockaddr_in6 *)&greqs.gsr_group;
 189		retv = ipv6_sock_mc_join_ssm(sk, greqs.gsr_interface,
 190					     &psin6->sin6_addr,
 191					     MCAST_INCLUDE);
 192		/* prior join w/ different source is ok */
 193		if (retv && retv != -EADDRINUSE)
 194			return retv;
 195		omode = MCAST_INCLUDE;
 196		add = 1;
 197	} else /* MCAST_LEAVE_SOURCE_GROUP */ {
 198		omode = MCAST_INCLUDE;
 199		add = 0;
 200	}
 201	return ip6_mc_source(add, omode, sk, &greqs);
 202}
 203
 204static int ipv6_set_mcast_msfilter(struct sock *sk, sockptr_t optval,
 205		int optlen)
 206{
 207	struct group_filter *gsf;
 208	int ret;
 209
 210	if (optlen < GROUP_FILTER_SIZE(0))
 211		return -EINVAL;
 212	if (optlen > READ_ONCE(sock_net(sk)->core.sysctl_optmem_max))
 213		return -ENOBUFS;
 214
 215	gsf = memdup_sockptr(optval, optlen);
 216	if (IS_ERR(gsf))
 217		return PTR_ERR(gsf);
 218
 219	/* numsrc >= (4G-140)/128 overflow in 32 bits */
 220	ret = -ENOBUFS;
 221	if (gsf->gf_numsrc >= 0x1ffffffU ||
 222	    gsf->gf_numsrc > sysctl_mld_max_msf)
 223		goto out_free_gsf;
 224
 225	ret = -EINVAL;
 226	if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen)
 227		goto out_free_gsf;
 228
 229	ret = ip6_mc_msfilter(sk, gsf, gsf->gf_slist_flex);
 230out_free_gsf:
 231	kfree(gsf);
 232	return ret;
 233}
 234
 235static int compat_ipv6_set_mcast_msfilter(struct sock *sk, sockptr_t optval,
 236		int optlen)
 237{
 238	const int size0 = offsetof(struct compat_group_filter, gf_slist_flex);
 239	struct compat_group_filter *gf32;
 240	void *p;
 241	int ret;
 242	int n;
 243
 244	if (optlen < size0)
 245		return -EINVAL;
 246	if (optlen > READ_ONCE(sock_net(sk)->core.sysctl_optmem_max) - 4)
 247		return -ENOBUFS;
 248
 249	p = kmalloc(optlen + 4, GFP_KERNEL);
 250	if (!p)
 251		return -ENOMEM;
 252
 253	gf32 = p + 4; /* we want ->gf_group and ->gf_slist_flex aligned */
 254	ret = -EFAULT;
 255	if (copy_from_sockptr(gf32, optval, optlen))
 256		goto out_free_p;
 257
 258	/* numsrc >= (4G-140)/128 overflow in 32 bits */
 259	ret = -ENOBUFS;
 260	n = gf32->gf_numsrc;
 261	if (n >= 0x1ffffffU || n > sysctl_mld_max_msf)
 262		goto out_free_p;
 263
 264	ret = -EINVAL;
 265	if (offsetof(struct compat_group_filter, gf_slist_flex[n]) > optlen)
 266		goto out_free_p;
 267
 268	ret = ip6_mc_msfilter(sk, &(struct group_filter){
 269			.gf_interface = gf32->gf_interface,
 270			.gf_group = gf32->gf_group,
 271			.gf_fmode = gf32->gf_fmode,
 272			.gf_numsrc = gf32->gf_numsrc}, gf32->gf_slist_flex);
 273
 274out_free_p:
 275	kfree(p);
 276	return ret;
 277}
 278
 279static int ipv6_mcast_join_leave(struct sock *sk, int optname,
 280		sockptr_t optval, int optlen)
 281{
 282	struct sockaddr_in6 *psin6;
 283	struct group_req greq;
 284
 285	if (optlen < sizeof(greq))
 286		return -EINVAL;
 287	if (copy_from_sockptr(&greq, optval, sizeof(greq)))
 288		return -EFAULT;
 289
 290	if (greq.gr_group.ss_family != AF_INET6)
 291		return -EADDRNOTAVAIL;
 292	psin6 = (struct sockaddr_in6 *)&greq.gr_group;
 293	if (optname == MCAST_JOIN_GROUP)
 294		return ipv6_sock_mc_join(sk, greq.gr_interface,
 295					 &psin6->sin6_addr);
 296	return ipv6_sock_mc_drop(sk, greq.gr_interface, &psin6->sin6_addr);
 297}
 298
 299static int compat_ipv6_mcast_join_leave(struct sock *sk, int optname,
 300		sockptr_t optval, int optlen)
 301{
 302	struct compat_group_req gr32;
 303	struct sockaddr_in6 *psin6;
 304
 305	if (optlen < sizeof(gr32))
 306		return -EINVAL;
 307	if (copy_from_sockptr(&gr32, optval, sizeof(gr32)))
 308		return -EFAULT;
 309
 310	if (gr32.gr_group.ss_family != AF_INET6)
 311		return -EADDRNOTAVAIL;
 312	psin6 = (struct sockaddr_in6 *)&gr32.gr_group;
 313	if (optname == MCAST_JOIN_GROUP)
 314		return ipv6_sock_mc_join(sk, gr32.gr_interface,
 315					&psin6->sin6_addr);
 316	return ipv6_sock_mc_drop(sk, gr32.gr_interface, &psin6->sin6_addr);
 317}
 318
 319static int ipv6_set_opt_hdr(struct sock *sk, int optname, sockptr_t optval,
 320		int optlen)
 321{
 322	struct ipv6_pinfo *np = inet6_sk(sk);
 323	struct ipv6_opt_hdr *new = NULL;
 324	struct net *net = sock_net(sk);
 325	struct ipv6_txoptions *opt;
 326	int err;
 327
 328	/* hop-by-hop / destination options are privileged option */
 329	if (optname != IPV6_RTHDR && !sockopt_ns_capable(net->user_ns, CAP_NET_RAW))
 330		return -EPERM;
 331
 332	/* remove any sticky options header with a zero option
 333	 * length, per RFC3542.
 334	 */
 335	if (optlen > 0) {
 336		if (sockptr_is_null(optval))
 337			return -EINVAL;
 338		if (optlen < sizeof(struct ipv6_opt_hdr) ||
 339		    optlen & 0x7 ||
 340		    optlen > 8 * 255)
 341			return -EINVAL;
 342
 343		new = memdup_sockptr(optval, optlen);
 344		if (IS_ERR(new))
 345			return PTR_ERR(new);
 346		if (unlikely(ipv6_optlen(new) > optlen)) {
 347			kfree(new);
 348			return -EINVAL;
 349		}
 350	}
 351
 352	opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
 353	opt = ipv6_renew_options(sk, opt, optname, new);
 354	kfree(new);
 355	if (IS_ERR(opt))
 356		return PTR_ERR(opt);
 357
 358	/* routing header option needs extra check */
 359	err = -EINVAL;
 360	if (optname == IPV6_RTHDR && opt && opt->srcrt) {
 361		struct ipv6_rt_hdr *rthdr = opt->srcrt;
 362		switch (rthdr->type) {
 363#if IS_ENABLED(CONFIG_IPV6_MIP6)
 364		case IPV6_SRCRT_TYPE_2:
 365			if (rthdr->hdrlen != 2 || rthdr->segments_left != 1)
 366				goto sticky_done;
 367			break;
 368#endif
 369		case IPV6_SRCRT_TYPE_4:
 370		{
 371			struct ipv6_sr_hdr *srh =
 372				(struct ipv6_sr_hdr *)opt->srcrt;
 373
 374			if (!seg6_validate_srh(srh, optlen, false))
 375				goto sticky_done;
 376			break;
 377		}
 378		default:
 379			goto sticky_done;
 380		}
 381	}
 382
 383	err = 0;
 384	opt = ipv6_update_options(sk, opt);
 385sticky_done:
 386	if (opt) {
 387		atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
 388		txopt_put(opt);
 389	}
 390	return err;
 391}
 392
 393int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
 394		       sockptr_t optval, unsigned int optlen)
 395{
 396	struct ipv6_pinfo *np = inet6_sk(sk);
 397	struct net *net = sock_net(sk);
 398	int val, valbool;
 399	int retv = -ENOPROTOOPT;
 400	bool needs_rtnl = setsockopt_needs_rtnl(optname);
 401
 402	if (sockptr_is_null(optval))
 403		val = 0;
 404	else {
 405		if (optlen >= sizeof(int)) {
 406			if (copy_from_sockptr(&val, optval, sizeof(val)))
 407				return -EFAULT;
 408		} else
 409			val = 0;
 410	}
 411
 412	valbool = (val != 0);
 413
 414	if (ip6_mroute_opt(optname))
 415		return ip6_mroute_setsockopt(sk, optname, optval, optlen);
 416
 417	/* Handle options that can be set without locking the socket. */
 418	switch (optname) {
 419	case IPV6_UNICAST_HOPS:
 420		if (optlen < sizeof(int))
 421			return -EINVAL;
 422		if (val > 255 || val < -1)
 423			return -EINVAL;
 424		WRITE_ONCE(np->hop_limit, val);
 425		return 0;
 426	case IPV6_MULTICAST_LOOP:
 427		if (optlen < sizeof(int))
 428			return -EINVAL;
 429		if (val != valbool)
 430			return -EINVAL;
 431		inet6_assign_bit(MC6_LOOP, sk, valbool);
 432		return 0;
 433	case IPV6_MULTICAST_HOPS:
 434		if (sk->sk_type == SOCK_STREAM)
 435			return retv;
 436		if (optlen < sizeof(int))
 437			return -EINVAL;
 438		if (val > 255 || val < -1)
 439			return -EINVAL;
 440		WRITE_ONCE(np->mcast_hops,
 441			   val == -1 ? IPV6_DEFAULT_MCASTHOPS : val);
 442		return 0;
 443	case IPV6_MTU:
 444		if (optlen < sizeof(int))
 445			return -EINVAL;
 446		if (val && val < IPV6_MIN_MTU)
 447			return -EINVAL;
 448		WRITE_ONCE(np->frag_size, val);
 449		return 0;
 450	case IPV6_MINHOPCOUNT:
 451		if (optlen < sizeof(int))
 452			return -EINVAL;
 453		if (val < 0 || val > 255)
 454			return -EINVAL;
 455
 456		if (val)
 457			static_branch_enable(&ip6_min_hopcount);
 458
 459		/* tcp_v6_err() and tcp_v6_rcv() might read min_hopcount
 460		 * while we are changing it.
 461		 */
 462		WRITE_ONCE(np->min_hopcount, val);
 463		return 0;
 464	case IPV6_RECVERR_RFC4884:
 465		if (optlen < sizeof(int))
 466			return -EINVAL;
 467		if (val < 0 || val > 1)
 468			return -EINVAL;
 469		inet6_assign_bit(RECVERR6_RFC4884, sk, valbool);
 470		return 0;
 471	case IPV6_MULTICAST_ALL:
 472		if (optlen < sizeof(int))
 473			return -EINVAL;
 474		inet6_assign_bit(MC6_ALL, sk, valbool);
 475		return 0;
 476	case IPV6_AUTOFLOWLABEL:
 477		inet6_assign_bit(AUTOFLOWLABEL, sk, valbool);
 478		inet6_set_bit(AUTOFLOWLABEL_SET, sk);
 479		return 0;
 480	case IPV6_DONTFRAG:
 481		inet6_assign_bit(DONTFRAG, sk, valbool);
 482		return 0;
 483	case IPV6_RECVERR:
 484		if (optlen < sizeof(int))
 485			return -EINVAL;
 486		inet6_assign_bit(RECVERR6, sk, valbool);
 487		if (!val)
 488			skb_errqueue_purge(&sk->sk_error_queue);
 489		return 0;
 490	case IPV6_ROUTER_ALERT_ISOLATE:
 491		if (optlen < sizeof(int))
 492			return -EINVAL;
 493		inet6_assign_bit(RTALERT_ISOLATE, sk, valbool);
 494		return 0;
 495	case IPV6_MTU_DISCOVER:
 496		if (optlen < sizeof(int))
 497			return -EINVAL;
 498		if (val < IPV6_PMTUDISC_DONT || val > IPV6_PMTUDISC_OMIT)
 499			return -EINVAL;
 500		WRITE_ONCE(np->pmtudisc, val);
 501		return 0;
 502	case IPV6_FLOWINFO_SEND:
 503		if (optlen < sizeof(int))
 504			return -EINVAL;
 505		inet6_assign_bit(SNDFLOW, sk, valbool);
 506		return 0;
 507	case IPV6_ADDR_PREFERENCES:
 508		if (optlen < sizeof(int))
 509			return -EINVAL;
 510		return ip6_sock_set_addr_preferences(sk, val);
 511	case IPV6_MULTICAST_IF:
 512		if (sk->sk_type == SOCK_STREAM)
 513			return -ENOPROTOOPT;
 514		if (optlen < sizeof(int))
 515			return -EINVAL;
 516		if (val) {
 517			struct net_device *dev;
 518			int bound_dev_if, midx;
 519
 520			rcu_read_lock();
 521
 522			dev = dev_get_by_index_rcu(net, val);
 523			if (!dev) {
 524				rcu_read_unlock();
 525				return -ENODEV;
 526			}
 527			midx = l3mdev_master_ifindex_rcu(dev);
 528
 529			rcu_read_unlock();
 530
 531			bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
 532			if (bound_dev_if &&
 533			    bound_dev_if != val &&
 534			    (!midx || midx != bound_dev_if))
 535				return -EINVAL;
 536		}
 537		WRITE_ONCE(np->mcast_oif, val);
 538		return 0;
 539	case IPV6_UNICAST_IF:
 540	{
 541		struct net_device *dev;
 542		int ifindex;
 543
 544		if (optlen != sizeof(int))
 545			return -EINVAL;
 546
 547		ifindex = (__force int)ntohl((__force __be32)val);
 548		if (!ifindex) {
 549			WRITE_ONCE(np->ucast_oif, 0);
 550			return 0;
 551		}
 552
 553		dev = dev_get_by_index(net, ifindex);
 554		if (!dev)
 555			return -EADDRNOTAVAIL;
 556		dev_put(dev);
 557
 558		if (READ_ONCE(sk->sk_bound_dev_if))
 559			return -EINVAL;
 560
 561		WRITE_ONCE(np->ucast_oif, ifindex);
 562		return 0;
 563	}
 564	}
 565	if (needs_rtnl)
 566		rtnl_lock();
 567	sockopt_lock_sock(sk);
 568
 569	/* Another thread has converted the socket into IPv4 with
 570	 * IPV6_ADDRFORM concurrently.
 571	 */
 572	if (unlikely(sk->sk_family != AF_INET6))
 573		goto unlock;
 574
 575	switch (optname) {
 576
 577	case IPV6_ADDRFORM:
 578		if (optlen < sizeof(int))
 579			goto e_inval;
 580		if (val == PF_INET) {
 581			if (sk->sk_type == SOCK_RAW)
 582				break;
 583
 584			if (sk->sk_protocol == IPPROTO_UDP ||
 585			    sk->sk_protocol == IPPROTO_UDPLITE) {
 586				struct udp_sock *up = udp_sk(sk);
 587				if (up->pending == AF_INET6) {
 588					retv = -EBUSY;
 589					break;
 590				}
 591			} else if (sk->sk_protocol == IPPROTO_TCP) {
 592				if (sk->sk_prot != &tcpv6_prot) {
 593					retv = -EBUSY;
 594					break;
 595				}
 596			} else {
 597				break;
 598			}
 599
 600			if (sk->sk_state != TCP_ESTABLISHED) {
 601				retv = -ENOTCONN;
 602				break;
 603			}
 604
 605			if (ipv6_only_sock(sk) ||
 606			    !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) {
 607				retv = -EADDRNOTAVAIL;
 608				break;
 609			}
 610
 611			__ipv6_sock_mc_close(sk);
 612			__ipv6_sock_ac_close(sk);
 613
 614			if (sk->sk_protocol == IPPROTO_TCP) {
 615				struct inet_connection_sock *icsk = inet_csk(sk);
 616
 617				sock_prot_inuse_add(net, sk->sk_prot, -1);
 618				sock_prot_inuse_add(net, &tcp_prot, 1);
 619
 620				/* Paired with READ_ONCE(sk->sk_prot) in inet6_stream_ops */
 621				WRITE_ONCE(sk->sk_prot, &tcp_prot);
 622				/* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
 623				WRITE_ONCE(icsk->icsk_af_ops, &ipv4_specific);
 624				WRITE_ONCE(sk->sk_socket->ops, &inet_stream_ops);
 625				WRITE_ONCE(sk->sk_family, PF_INET);
 626				tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
 627			} else {
 628				struct proto *prot = &udp_prot;
 629
 630				if (sk->sk_protocol == IPPROTO_UDPLITE)
 631					prot = &udplite_prot;
 632
 633				sock_prot_inuse_add(net, sk->sk_prot, -1);
 634				sock_prot_inuse_add(net, prot, 1);
 635
 636				/* Paired with READ_ONCE(sk->sk_prot) in inet6_dgram_ops */
 637				WRITE_ONCE(sk->sk_prot, prot);
 638				WRITE_ONCE(sk->sk_socket->ops, &inet_dgram_ops);
 639				WRITE_ONCE(sk->sk_family, PF_INET);
 640			}
 641
 642			/* Disable all options not to allocate memory anymore,
 643			 * but there is still a race.  See the lockless path
 644			 * in udpv6_sendmsg() and ipv6_local_rxpmtu().
 645			 */
 646			np->rxopt.all = 0;
 647
 648			inet6_cleanup_sock(sk);
 649
 650			module_put(THIS_MODULE);
 651			retv = 0;
 652			break;
 653		}
 654		goto e_inval;
 655
 656	case IPV6_V6ONLY:
 657		if (optlen < sizeof(int) ||
 658		    inet_sk(sk)->inet_num)
 659			goto e_inval;
 660		sk->sk_ipv6only = valbool;
 661		retv = 0;
 662		break;
 663
 664	case IPV6_RECVPKTINFO:
 665		if (optlen < sizeof(int))
 666			goto e_inval;
 667		np->rxopt.bits.rxinfo = valbool;
 668		retv = 0;
 669		break;
 670
 671	case IPV6_2292PKTINFO:
 672		if (optlen < sizeof(int))
 673			goto e_inval;
 674		np->rxopt.bits.rxoinfo = valbool;
 675		retv = 0;
 676		break;
 677
 678	case IPV6_RECVHOPLIMIT:
 679		if (optlen < sizeof(int))
 680			goto e_inval;
 681		np->rxopt.bits.rxhlim = valbool;
 682		retv = 0;
 683		break;
 684
 685	case IPV6_2292HOPLIMIT:
 686		if (optlen < sizeof(int))
 687			goto e_inval;
 688		np->rxopt.bits.rxohlim = valbool;
 689		retv = 0;
 690		break;
 691
 692	case IPV6_RECVRTHDR:
 693		if (optlen < sizeof(int))
 694			goto e_inval;
 695		np->rxopt.bits.srcrt = valbool;
 696		retv = 0;
 697		break;
 698
 699	case IPV6_2292RTHDR:
 700		if (optlen < sizeof(int))
 701			goto e_inval;
 702		np->rxopt.bits.osrcrt = valbool;
 703		retv = 0;
 704		break;
 705
 706	case IPV6_RECVHOPOPTS:
 707		if (optlen < sizeof(int))
 708			goto e_inval;
 709		np->rxopt.bits.hopopts = valbool;
 710		retv = 0;
 711		break;
 712
 713	case IPV6_2292HOPOPTS:
 714		if (optlen < sizeof(int))
 715			goto e_inval;
 716		np->rxopt.bits.ohopopts = valbool;
 717		retv = 0;
 718		break;
 719
 720	case IPV6_RECVDSTOPTS:
 721		if (optlen < sizeof(int))
 722			goto e_inval;
 723		np->rxopt.bits.dstopts = valbool;
 724		retv = 0;
 725		break;
 726
 727	case IPV6_2292DSTOPTS:
 728		if (optlen < sizeof(int))
 729			goto e_inval;
 730		np->rxopt.bits.odstopts = valbool;
 731		retv = 0;
 732		break;
 733
 734	case IPV6_TCLASS:
 735		if (optlen < sizeof(int))
 736			goto e_inval;
 737		if (val < -1 || val > 0xff)
 738			goto e_inval;
 739		/* RFC 3542, 6.5: default traffic class of 0x0 */
 740		if (val == -1)
 741			val = 0;
 742		if (sk->sk_type == SOCK_STREAM) {
 743			val &= ~INET_ECN_MASK;
 744			val |= np->tclass & INET_ECN_MASK;
 745		}
 746		if (np->tclass != val) {
 747			np->tclass = val;
 748			sk_dst_reset(sk);
 749		}
 750		retv = 0;
 751		break;
 752
 753	case IPV6_RECVTCLASS:
 754		if (optlen < sizeof(int))
 755			goto e_inval;
 756		np->rxopt.bits.rxtclass = valbool;
 757		retv = 0;
 758		break;
 759
 760	case IPV6_FLOWINFO:
 761		if (optlen < sizeof(int))
 762			goto e_inval;
 763		np->rxopt.bits.rxflow = valbool;
 764		retv = 0;
 765		break;
 766
 767	case IPV6_RECVPATHMTU:
 768		if (optlen < sizeof(int))
 769			goto e_inval;
 770		np->rxopt.bits.rxpmtu = valbool;
 771		retv = 0;
 772		break;
 773
 774	case IPV6_TRANSPARENT:
 775		if (valbool && !sockopt_ns_capable(net->user_ns, CAP_NET_RAW) &&
 776		    !sockopt_ns_capable(net->user_ns, CAP_NET_ADMIN)) {
 777			retv = -EPERM;
 778			break;
 779		}
 780		if (optlen < sizeof(int))
 781			goto e_inval;
 782		/* we don't have a separate transparent bit for IPV6 we use the one in the IPv4 socket */
 783		inet_assign_bit(TRANSPARENT, sk, valbool);
 784		retv = 0;
 785		break;
 786
 787	case IPV6_FREEBIND:
 788		if (optlen < sizeof(int))
 789			goto e_inval;
 790		/* we also don't have a separate freebind bit for IPV6 */
 791		inet_assign_bit(FREEBIND, sk, valbool);
 792		retv = 0;
 793		break;
 794
 795	case IPV6_RECVORIGDSTADDR:
 796		if (optlen < sizeof(int))
 797			goto e_inval;
 798		np->rxopt.bits.rxorigdstaddr = valbool;
 799		retv = 0;
 800		break;
 801
 802	case IPV6_HOPOPTS:
 803	case IPV6_RTHDRDSTOPTS:
 804	case IPV6_RTHDR:
 805	case IPV6_DSTOPTS:
 806		retv = ipv6_set_opt_hdr(sk, optname, optval, optlen);
 807		break;
 808
 809	case IPV6_PKTINFO:
 810	{
 811		struct in6_pktinfo pkt;
 812
 813		if (optlen == 0)
 814			goto e_inval;
 815		else if (optlen < sizeof(struct in6_pktinfo) ||
 816			 sockptr_is_null(optval))
 817			goto e_inval;
 818
 819		if (copy_from_sockptr(&pkt, optval, sizeof(pkt))) {
 820			retv = -EFAULT;
 821			break;
 822		}
 823		if (!sk_dev_equal_l3scope(sk, pkt.ipi6_ifindex))
 824			goto e_inval;
 825
 826		np->sticky_pktinfo.ipi6_ifindex = pkt.ipi6_ifindex;
 827		np->sticky_pktinfo.ipi6_addr = pkt.ipi6_addr;
 828		retv = 0;
 829		break;
 830	}
 831
 832	case IPV6_2292PKTOPTIONS:
 833	{
 834		struct ipv6_txoptions *opt = NULL;
 835		struct msghdr msg;
 836		struct flowi6 fl6;
 837		struct ipcm6_cookie ipc6;
 838
 839		memset(&fl6, 0, sizeof(fl6));
 840		fl6.flowi6_oif = sk->sk_bound_dev_if;
 841		fl6.flowi6_mark = sk->sk_mark;
 842
 843		if (optlen == 0)
 844			goto update;
 845
 846		/* 1K is probably excessive
 847		 * 1K is surely not enough, 2K per standard header is 16K.
 848		 */
 849		retv = -EINVAL;
 850		if (optlen > 64*1024)
 851			break;
 852
 853		opt = sock_kmalloc(sk, sizeof(*opt) + optlen, GFP_KERNEL);
 854		retv = -ENOBUFS;
 855		if (!opt)
 856			break;
 857
 858		memset(opt, 0, sizeof(*opt));
 859		refcount_set(&opt->refcnt, 1);
 860		opt->tot_len = sizeof(*opt) + optlen;
 861		retv = -EFAULT;
 862		if (copy_from_sockptr(opt + 1, optval, optlen))
 863			goto done;
 864
 865		msg.msg_controllen = optlen;
 866		msg.msg_control_is_user = false;
 867		msg.msg_control = (void *)(opt+1);
 868		ipc6.opt = opt;
 869
 870		retv = ip6_datagram_send_ctl(net, sk, &msg, &fl6, &ipc6);
 871		if (retv)
 872			goto done;
 873update:
 874		retv = 0;
 875		opt = ipv6_update_options(sk, opt);
 876done:
 877		if (opt) {
 878			atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
 879			txopt_put(opt);
 880		}
 881		break;
 882	}
 883
 884	case IPV6_ADD_MEMBERSHIP:
 885	case IPV6_DROP_MEMBERSHIP:
 886	{
 887		struct ipv6_mreq mreq;
 888
 889		if (optlen < sizeof(struct ipv6_mreq))
 890			goto e_inval;
 891
 892		retv = -EPROTO;
 893		if (inet_test_bit(IS_ICSK, sk))
 894			break;
 895
 896		retv = -EFAULT;
 897		if (copy_from_sockptr(&mreq, optval, sizeof(struct ipv6_mreq)))
 898			break;
 899
 900		if (optname == IPV6_ADD_MEMBERSHIP)
 901			retv = ipv6_sock_mc_join(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr);
 902		else
 903			retv = ipv6_sock_mc_drop(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr);
 904		break;
 905	}
 906	case IPV6_JOIN_ANYCAST:
 907	case IPV6_LEAVE_ANYCAST:
 908	{
 909		struct ipv6_mreq mreq;
 910
 911		if (optlen < sizeof(struct ipv6_mreq))
 912			goto e_inval;
 913
 914		retv = -EFAULT;
 915		if (copy_from_sockptr(&mreq, optval, sizeof(struct ipv6_mreq)))
 916			break;
 917
 918		if (optname == IPV6_JOIN_ANYCAST)
 919			retv = ipv6_sock_ac_join(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_acaddr);
 920		else
 921			retv = ipv6_sock_ac_drop(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_acaddr);
 922		break;
 923	}
 924	case MCAST_JOIN_GROUP:
 925	case MCAST_LEAVE_GROUP:
 926		if (in_compat_syscall())
 927			retv = compat_ipv6_mcast_join_leave(sk, optname, optval,
 928							    optlen);
 929		else
 930			retv = ipv6_mcast_join_leave(sk, optname, optval,
 931						     optlen);
 932		break;
 933	case MCAST_JOIN_SOURCE_GROUP:
 934	case MCAST_LEAVE_SOURCE_GROUP:
 935	case MCAST_BLOCK_SOURCE:
 936	case MCAST_UNBLOCK_SOURCE:
 937		retv = do_ipv6_mcast_group_source(sk, optname, optval, optlen);
 938		break;
 939	case MCAST_MSFILTER:
 940		if (in_compat_syscall())
 941			retv = compat_ipv6_set_mcast_msfilter(sk, optval,
 942							      optlen);
 943		else
 944			retv = ipv6_set_mcast_msfilter(sk, optval, optlen);
 945		break;
 946	case IPV6_ROUTER_ALERT:
 947		if (optlen < sizeof(int))
 948			goto e_inval;
 949		retv = ip6_ra_control(sk, val);
 950		if (retv == 0)
 951			inet6_assign_bit(RTALERT, sk, valbool);
 952		break;
 953	case IPV6_FLOWLABEL_MGR:
 954		retv = ipv6_flowlabel_opt(sk, optval, optlen);
 955		break;
 956	case IPV6_IPSEC_POLICY:
 957	case IPV6_XFRM_POLICY:
 958		retv = -EPERM;
 959		if (!sockopt_ns_capable(net->user_ns, CAP_NET_ADMIN))
 960			break;
 961		retv = xfrm_user_policy(sk, optname, optval, optlen);
 962		break;
 963
 964	case IPV6_RECVFRAGSIZE:
 965		np->rxopt.bits.recvfragsize = valbool;
 966		retv = 0;
 967		break;
 968	}
 969
 970unlock:
 971	sockopt_release_sock(sk);
 972	if (needs_rtnl)
 973		rtnl_unlock();
 974
 975	return retv;
 976
 977e_inval:
 978	retv = -EINVAL;
 979	goto unlock;
 980}
 981
 982int ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
 983		    unsigned int optlen)
 984{
 985	int err;
 986
 987	if (level == SOL_IP && sk->sk_type != SOCK_RAW)
 988		return ip_setsockopt(sk, level, optname, optval, optlen);
 989
 990	if (level != SOL_IPV6)
 991		return -ENOPROTOOPT;
 992
 993	err = do_ipv6_setsockopt(sk, level, optname, optval, optlen);
 994#ifdef CONFIG_NETFILTER
 995	/* we need to exclude all possible ENOPROTOOPTs except default case */
 996	if (err == -ENOPROTOOPT && optname != IPV6_IPSEC_POLICY &&
 997			optname != IPV6_XFRM_POLICY)
 998		err = nf_setsockopt(sk, PF_INET6, optname, optval, optlen);
 999#endif
1000	return err;
1001}
1002EXPORT_SYMBOL(ipv6_setsockopt);
1003
1004static int ipv6_getsockopt_sticky(struct sock *sk, struct ipv6_txoptions *opt,
1005				  int optname, sockptr_t optval, int len)
1006{
1007	struct ipv6_opt_hdr *hdr;
1008
1009	if (!opt)
1010		return 0;
1011
1012	switch (optname) {
1013	case IPV6_HOPOPTS:
1014		hdr = opt->hopopt;
1015		break;
1016	case IPV6_RTHDRDSTOPTS:
1017		hdr = opt->dst0opt;
1018		break;
1019	case IPV6_RTHDR:
1020		hdr = (struct ipv6_opt_hdr *)opt->srcrt;
1021		break;
1022	case IPV6_DSTOPTS:
1023		hdr = opt->dst1opt;
1024		break;
1025	default:
1026		return -EINVAL;	/* should not happen */
1027	}
1028
1029	if (!hdr)
1030		return 0;
1031
1032	len = min_t(unsigned int, len, ipv6_optlen(hdr));
1033	if (copy_to_sockptr(optval, hdr, len))
1034		return -EFAULT;
1035	return len;
1036}
1037
1038static int ipv6_get_msfilter(struct sock *sk, sockptr_t optval,
1039			     sockptr_t optlen, int len)
1040{
1041	const int size0 = offsetof(struct group_filter, gf_slist_flex);
1042	struct group_filter gsf;
1043	int num;
1044	int err;
1045
1046	if (len < size0)
1047		return -EINVAL;
1048	if (copy_from_sockptr(&gsf, optval, size0))
1049		return -EFAULT;
1050	if (gsf.gf_group.ss_family != AF_INET6)
1051		return -EADDRNOTAVAIL;
1052	num = gsf.gf_numsrc;
1053	sockopt_lock_sock(sk);
1054	err = ip6_mc_msfget(sk, &gsf, optval, size0);
1055	if (!err) {
1056		if (num > gsf.gf_numsrc)
1057			num = gsf.gf_numsrc;
1058		len = GROUP_FILTER_SIZE(num);
1059		if (copy_to_sockptr(optlen, &len, sizeof(int)) ||
1060		    copy_to_sockptr(optval, &gsf, size0))
1061			err = -EFAULT;
1062	}
1063	sockopt_release_sock(sk);
1064	return err;
1065}
1066
1067static int compat_ipv6_get_msfilter(struct sock *sk, sockptr_t optval,
1068				    sockptr_t optlen, int len)
1069{
1070	const int size0 = offsetof(struct compat_group_filter, gf_slist_flex);
1071	struct compat_group_filter gf32;
1072	struct group_filter gf;
1073	int err;
1074	int num;
1075
1076	if (len < size0)
1077		return -EINVAL;
1078
1079	if (copy_from_sockptr(&gf32, optval, size0))
1080		return -EFAULT;
1081	gf.gf_interface = gf32.gf_interface;
1082	gf.gf_fmode = gf32.gf_fmode;
1083	num = gf.gf_numsrc = gf32.gf_numsrc;
1084	gf.gf_group = gf32.gf_group;
1085
1086	if (gf.gf_group.ss_family != AF_INET6)
1087		return -EADDRNOTAVAIL;
1088
1089	sockopt_lock_sock(sk);
1090	err = ip6_mc_msfget(sk, &gf, optval, size0);
1091	sockopt_release_sock(sk);
1092	if (err)
1093		return err;
1094	if (num > gf.gf_numsrc)
1095		num = gf.gf_numsrc;
1096	len = GROUP_FILTER_SIZE(num) - (sizeof(gf)-sizeof(gf32));
1097	if (copy_to_sockptr(optlen, &len, sizeof(int)) ||
1098	    copy_to_sockptr_offset(optval, offsetof(struct compat_group_filter, gf_fmode),
1099				   &gf.gf_fmode, sizeof(gf32.gf_fmode)) ||
1100	    copy_to_sockptr_offset(optval, offsetof(struct compat_group_filter, gf_numsrc),
1101				   &gf.gf_numsrc, sizeof(gf32.gf_numsrc)))
1102		return -EFAULT;
1103	return 0;
1104}
1105
1106int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
1107		       sockptr_t optval, sockptr_t optlen)
1108{
1109	struct ipv6_pinfo *np = inet6_sk(sk);
1110	int len;
1111	int val;
1112
1113	if (ip6_mroute_opt(optname))
1114		return ip6_mroute_getsockopt(sk, optname, optval, optlen);
1115
1116	if (copy_from_sockptr(&len, optlen, sizeof(int)))
1117		return -EFAULT;
1118	switch (optname) {
1119	case IPV6_ADDRFORM:
1120		if (sk->sk_protocol != IPPROTO_UDP &&
1121		    sk->sk_protocol != IPPROTO_UDPLITE &&
1122		    sk->sk_protocol != IPPROTO_TCP)
1123			return -ENOPROTOOPT;
1124		if (sk->sk_state != TCP_ESTABLISHED)
1125			return -ENOTCONN;
1126		val = sk->sk_family;
1127		break;
1128	case MCAST_MSFILTER:
1129		if (in_compat_syscall())
1130			return compat_ipv6_get_msfilter(sk, optval, optlen, len);
1131		return ipv6_get_msfilter(sk, optval, optlen, len);
1132	case IPV6_2292PKTOPTIONS:
1133	{
1134		struct msghdr msg;
1135		struct sk_buff *skb;
1136
1137		if (sk->sk_type != SOCK_STREAM)
1138			return -ENOPROTOOPT;
1139
1140		if (optval.is_kernel) {
1141			msg.msg_control_is_user = false;
1142			msg.msg_control = optval.kernel;
1143		} else {
1144			msg.msg_control_is_user = true;
1145			msg.msg_control_user = optval.user;
1146		}
1147		msg.msg_controllen = len;
1148		msg.msg_flags = 0;
1149
1150		sockopt_lock_sock(sk);
1151		skb = np->pktoptions;
1152		if (skb)
1153			ip6_datagram_recv_ctl(sk, &msg, skb);
1154		sockopt_release_sock(sk);
1155		if (!skb) {
1156			if (np->rxopt.bits.rxinfo) {
1157				int mcast_oif = READ_ONCE(np->mcast_oif);
1158				struct in6_pktinfo src_info;
1159
1160				src_info.ipi6_ifindex = mcast_oif ? :
1161					np->sticky_pktinfo.ipi6_ifindex;
1162				src_info.ipi6_addr = mcast_oif ? sk->sk_v6_daddr : np->sticky_pktinfo.ipi6_addr;
1163				put_cmsg(&msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
1164			}
1165			if (np->rxopt.bits.rxhlim) {
1166				int hlim = READ_ONCE(np->mcast_hops);
1167
1168				put_cmsg(&msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
1169			}
1170			if (np->rxopt.bits.rxtclass) {
1171				int tclass = (int)ip6_tclass(np->rcv_flowinfo);
1172
1173				put_cmsg(&msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
1174			}
1175			if (np->rxopt.bits.rxoinfo) {
1176				int mcast_oif = READ_ONCE(np->mcast_oif);
1177				struct in6_pktinfo src_info;
1178
1179				src_info.ipi6_ifindex = mcast_oif ? :
1180					np->sticky_pktinfo.ipi6_ifindex;
1181				src_info.ipi6_addr = mcast_oif ? sk->sk_v6_daddr :
1182								 np->sticky_pktinfo.ipi6_addr;
1183				put_cmsg(&msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
1184			}
1185			if (np->rxopt.bits.rxohlim) {
1186				int hlim = READ_ONCE(np->mcast_hops);
1187
1188				put_cmsg(&msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
1189			}
1190			if (np->rxopt.bits.rxflow) {
1191				__be32 flowinfo = np->rcv_flowinfo;
1192
1193				put_cmsg(&msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
1194			}
1195		}
1196		len -= msg.msg_controllen;
1197		return copy_to_sockptr(optlen, &len, sizeof(int));
1198	}
1199	case IPV6_MTU:
1200	{
1201		struct dst_entry *dst;
1202
1203		val = 0;
1204		rcu_read_lock();
1205		dst = __sk_dst_get(sk);
1206		if (dst)
1207			val = dst_mtu(dst);
1208		rcu_read_unlock();
1209		if (!val)
1210			return -ENOTCONN;
1211		break;
1212	}
1213
1214	case IPV6_V6ONLY:
1215		val = sk->sk_ipv6only;
1216		break;
1217
1218	case IPV6_RECVPKTINFO:
1219		val = np->rxopt.bits.rxinfo;
1220		break;
1221
1222	case IPV6_2292PKTINFO:
1223		val = np->rxopt.bits.rxoinfo;
1224		break;
1225
1226	case IPV6_RECVHOPLIMIT:
1227		val = np->rxopt.bits.rxhlim;
1228		break;
1229
1230	case IPV6_2292HOPLIMIT:
1231		val = np->rxopt.bits.rxohlim;
1232		break;
1233
1234	case IPV6_RECVRTHDR:
1235		val = np->rxopt.bits.srcrt;
1236		break;
1237
1238	case IPV6_2292RTHDR:
1239		val = np->rxopt.bits.osrcrt;
1240		break;
1241
1242	case IPV6_HOPOPTS:
1243	case IPV6_RTHDRDSTOPTS:
1244	case IPV6_RTHDR:
1245	case IPV6_DSTOPTS:
1246	{
1247		struct ipv6_txoptions *opt;
1248
1249		sockopt_lock_sock(sk);
1250		opt = rcu_dereference_protected(np->opt,
1251						lockdep_sock_is_held(sk));
1252		len = ipv6_getsockopt_sticky(sk, opt, optname, optval, len);
1253		sockopt_release_sock(sk);
1254		/* check if ipv6_getsockopt_sticky() returns err code */
1255		if (len < 0)
1256			return len;
1257		return copy_to_sockptr(optlen, &len, sizeof(int));
1258	}
1259
1260	case IPV6_RECVHOPOPTS:
1261		val = np->rxopt.bits.hopopts;
1262		break;
1263
1264	case IPV6_2292HOPOPTS:
1265		val = np->rxopt.bits.ohopopts;
1266		break;
1267
1268	case IPV6_RECVDSTOPTS:
1269		val = np->rxopt.bits.dstopts;
1270		break;
1271
1272	case IPV6_2292DSTOPTS:
1273		val = np->rxopt.bits.odstopts;
1274		break;
1275
1276	case IPV6_TCLASS:
1277		val = np->tclass;
1278		break;
1279
1280	case IPV6_RECVTCLASS:
1281		val = np->rxopt.bits.rxtclass;
1282		break;
1283
1284	case IPV6_FLOWINFO:
1285		val = np->rxopt.bits.rxflow;
1286		break;
1287
1288	case IPV6_RECVPATHMTU:
1289		val = np->rxopt.bits.rxpmtu;
1290		break;
1291
1292	case IPV6_PATHMTU:
1293	{
1294		struct dst_entry *dst;
1295		struct ip6_mtuinfo mtuinfo;
1296
1297		if (len < sizeof(mtuinfo))
1298			return -EINVAL;
1299
1300		len = sizeof(mtuinfo);
1301		memset(&mtuinfo, 0, sizeof(mtuinfo));
1302
1303		rcu_read_lock();
1304		dst = __sk_dst_get(sk);
1305		if (dst)
1306			mtuinfo.ip6m_mtu = dst_mtu(dst);
1307		rcu_read_unlock();
1308		if (!mtuinfo.ip6m_mtu)
1309			return -ENOTCONN;
1310
1311		if (copy_to_sockptr(optlen, &len, sizeof(int)))
1312			return -EFAULT;
1313		if (copy_to_sockptr(optval, &mtuinfo, len))
1314			return -EFAULT;
1315
1316		return 0;
1317	}
1318
1319	case IPV6_TRANSPARENT:
1320		val = inet_test_bit(TRANSPARENT, sk);
1321		break;
1322
1323	case IPV6_FREEBIND:
1324		val = inet_test_bit(FREEBIND, sk);
1325		break;
1326
1327	case IPV6_RECVORIGDSTADDR:
1328		val = np->rxopt.bits.rxorigdstaddr;
1329		break;
1330
1331	case IPV6_UNICAST_HOPS:
1332	case IPV6_MULTICAST_HOPS:
1333	{
1334		struct dst_entry *dst;
1335
1336		if (optname == IPV6_UNICAST_HOPS)
1337			val = READ_ONCE(np->hop_limit);
1338		else
1339			val = READ_ONCE(np->mcast_hops);
1340
1341		if (val < 0) {
1342			rcu_read_lock();
1343			dst = __sk_dst_get(sk);
1344			if (dst)
1345				val = ip6_dst_hoplimit(dst);
1346			rcu_read_unlock();
1347		}
1348
1349		if (val < 0)
1350			val = READ_ONCE(sock_net(sk)->ipv6.devconf_all->hop_limit);
1351		break;
1352	}
1353
1354	case IPV6_MULTICAST_LOOP:
1355		val = inet6_test_bit(MC6_LOOP, sk);
1356		break;
1357
1358	case IPV6_MULTICAST_IF:
1359		val = READ_ONCE(np->mcast_oif);
1360		break;
1361
1362	case IPV6_MULTICAST_ALL:
1363		val = inet6_test_bit(MC6_ALL, sk);
1364		break;
1365
1366	case IPV6_UNICAST_IF:
1367		val = (__force int)htonl((__u32) READ_ONCE(np->ucast_oif));
1368		break;
1369
1370	case IPV6_MTU_DISCOVER:
1371		val = READ_ONCE(np->pmtudisc);
1372		break;
1373
1374	case IPV6_RECVERR:
1375		val = inet6_test_bit(RECVERR6, sk);
1376		break;
1377
1378	case IPV6_FLOWINFO_SEND:
1379		val = inet6_test_bit(SNDFLOW, sk);
1380		break;
1381
1382	case IPV6_FLOWLABEL_MGR:
1383	{
1384		struct in6_flowlabel_req freq;
1385		int flags;
1386
1387		if (len < sizeof(freq))
1388			return -EINVAL;
1389
1390		if (copy_from_sockptr(&freq, optval, sizeof(freq)))
1391			return -EFAULT;
1392
1393		if (freq.flr_action != IPV6_FL_A_GET)
1394			return -EINVAL;
1395
1396		len = sizeof(freq);
1397		flags = freq.flr_flags;
1398
1399		memset(&freq, 0, sizeof(freq));
1400
1401		val = ipv6_flowlabel_opt_get(sk, &freq, flags);
1402		if (val < 0)
1403			return val;
1404
1405		if (copy_to_sockptr(optlen, &len, sizeof(int)))
1406			return -EFAULT;
1407		if (copy_to_sockptr(optval, &freq, len))
1408			return -EFAULT;
1409
1410		return 0;
1411	}
1412
1413	case IPV6_ADDR_PREFERENCES:
1414		{
1415		u8 srcprefs = READ_ONCE(np->srcprefs);
1416		val = 0;
1417
1418		if (srcprefs & IPV6_PREFER_SRC_TMP)
1419			val |= IPV6_PREFER_SRC_TMP;
1420		else if (srcprefs & IPV6_PREFER_SRC_PUBLIC)
1421			val |= IPV6_PREFER_SRC_PUBLIC;
1422		else {
1423			/* XXX: should we return system default? */
1424			val |= IPV6_PREFER_SRC_PUBTMP_DEFAULT;
1425		}
1426
1427		if (srcprefs & IPV6_PREFER_SRC_COA)
1428			val |= IPV6_PREFER_SRC_COA;
1429		else
1430			val |= IPV6_PREFER_SRC_HOME;
1431		break;
1432		}
1433	case IPV6_MINHOPCOUNT:
1434		val = READ_ONCE(np->min_hopcount);
1435		break;
1436
1437	case IPV6_DONTFRAG:
1438		val = inet6_test_bit(DONTFRAG, sk);
1439		break;
1440
1441	case IPV6_AUTOFLOWLABEL:
1442		val = ip6_autoflowlabel(sock_net(sk), sk);
1443		break;
1444
1445	case IPV6_RECVFRAGSIZE:
1446		val = np->rxopt.bits.recvfragsize;
1447		break;
1448
1449	case IPV6_ROUTER_ALERT:
1450		val = inet6_test_bit(RTALERT, sk);
1451		break;
1452
1453	case IPV6_ROUTER_ALERT_ISOLATE:
1454		val = inet6_test_bit(RTALERT_ISOLATE, sk);
1455		break;
1456
1457	case IPV6_RECVERR_RFC4884:
1458		val = inet6_test_bit(RECVERR6_RFC4884, sk);
1459		break;
1460
1461	default:
1462		return -ENOPROTOOPT;
1463	}
1464	len = min_t(unsigned int, sizeof(int), len);
1465	if (copy_to_sockptr(optlen, &len, sizeof(int)))
1466		return -EFAULT;
1467	if (copy_to_sockptr(optval, &val, len))
1468		return -EFAULT;
1469	return 0;
1470}
1471
1472int ipv6_getsockopt(struct sock *sk, int level, int optname,
1473		    char __user *optval, int __user *optlen)
1474{
1475	int err;
1476
1477	if (level == SOL_IP && sk->sk_type != SOCK_RAW)
1478		return ip_getsockopt(sk, level, optname, optval, optlen);
1479
1480	if (level != SOL_IPV6)
1481		return -ENOPROTOOPT;
1482
1483	err = do_ipv6_getsockopt(sk, level, optname,
1484				 USER_SOCKPTR(optval), USER_SOCKPTR(optlen));
1485#ifdef CONFIG_NETFILTER
1486	/* we need to exclude all possible ENOPROTOOPTs except default case */
1487	if (err == -ENOPROTOOPT && optname != IPV6_2292PKTOPTIONS) {
1488		int len;
1489
1490		if (get_user(len, optlen))
1491			return -EFAULT;
1492
1493		err = nf_getsockopt(sk, PF_INET6, optname, optval, &len);
1494		if (err >= 0)
1495			err = put_user(len, optlen);
1496	}
1497#endif
1498	return err;
1499}
1500EXPORT_SYMBOL(ipv6_getsockopt);