// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   *	IPv6 BSD socket options interface

   *	Linux INET6 implementation

   *
   *	Authors:

   *	Pedro Roque		<roque@di.fc.ul.pt>

   *
   *	Based on linux/net/ipv4/ip_sockglue.c
   *

   *	FIXME: Make the setsockopt code POSIX compliant: That is
   *

   *	o	Truncate getsockopt returns
   *	o	Return an optlen of the truncated length if need be
   *
   *	Changes:
   *	David L Stevens <dlstevens@us.ibm.com>:
   *		- added multicast source filtering API for MLDv2
   */
  
  #include <linux/module.h>

  #include <linux/capability.h>

  #include <linux/errno.h>
  #include <linux/types.h>
  #include <linux/socket.h>
  #include <linux/sockios.h>

  #include <linux/net.h>
  #include <linux/in6.h>

  #include <linux/mroute6.h>

  #include <linux/netdevice.h>
  #include <linux/if_arp.h>
  #include <linux/init.h>
  #include <linux/sysctl.h>
  #include <linux/netfilter.h>

  #include <linux/slab.h>

  
  #include <net/sock.h>
  #include <net/snmp.h>
  #include <net/ipv6.h>
  #include <net/ndisc.h>
  #include <net/protocol.h>
  #include <net/transp_v6.h>
  #include <net/ip6_route.h>
  #include <net/addrconf.h>
  #include <net/inet_common.h>
  #include <net/tcp.h>
  #include <net/udp.h>

  #include <net/udplite.h>

  #include <net/xfrm.h>

  #include <net/compat.h>

  #include <net/seg6.h>

  #include <linux/uaccess.h>

  struct ip6_ra_chain *ip6_ra_chain;
  DEFINE_RWLOCK(ip6_ra_lock);

  int ip6_ra_control(struct sock *sk, int sel)

  {
  	struct ip6_ra_chain *ra, *new_ra, **rap;
  
  	/* RA packet may be delivered ONLY to IPPROTO_RAW socket */

  	if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num != IPPROTO_RAW)

  		return -ENOPROTOOPT;

  	new_ra = (sel >= 0) ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;

  	if (sel >= 0 && !new_ra)
  		return -ENOMEM;

  
  	write_lock_bh(&ip6_ra_lock);

  	for (rap = &ip6_ra_chain; (ra = *rap) != NULL; rap = &ra->next) {

  		if (ra->sk == sk) {

  			if (sel >= 0) {

  				write_unlock_bh(&ip6_ra_lock);

  				kfree(new_ra);

  				return -EADDRINUSE;
  			}
  
  			*rap = ra->next;
  			write_unlock_bh(&ip6_ra_lock);

  			sock_put(sk);
  			kfree(ra);
  			return 0;
  		}
  	}

  	if (!new_ra) {

  		write_unlock_bh(&ip6_ra_lock);
  		return -ENOBUFS;
  	}
  	new_ra->sk = sk;
  	new_ra->sel = sel;

  	new_ra->next = ra;
  	*rap = new_ra;
  	sock_hold(sk);
  	write_unlock_bh(&ip6_ra_lock);
  	return 0;
  }

  struct ipv6_txoptions *ipv6_update_options(struct sock *sk,
  					   struct ipv6_txoptions *opt)
  {
  	if (inet_sk(sk)->is_icsk) {
  		if (opt &&
  		    !((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) &&

  		    inet_sk(sk)->inet_daddr != LOOPBACK4_IPV6) {

  			struct inet_connection_sock *icsk = inet_csk(sk);
  			icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen;
  			icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
  		}

  	}

  	opt = xchg((__force struct ipv6_txoptions **)&inet6_sk(sk)->opt,
  		   opt);

  	sk_dst_reset(sk);
  
  	return opt;
  }

  static bool setsockopt_needs_rtnl(int optname)
  {
  	switch (optname) {

  	case IPV6_ADDRFORM:

  	case IPV6_ADD_MEMBERSHIP:
  	case IPV6_DROP_MEMBERSHIP:

  	case IPV6_JOIN_ANYCAST:
  	case IPV6_LEAVE_ANYCAST:

  	case MCAST_JOIN_GROUP:
  	case MCAST_LEAVE_GROUP:

  	case MCAST_JOIN_SOURCE_GROUP:
  	case MCAST_LEAVE_SOURCE_GROUP:
  	case MCAST_BLOCK_SOURCE:
  	case MCAST_UNBLOCK_SOURCE:
  	case MCAST_MSFILTER:

  		return true;
  	}
  	return false;
  }

  static int copy_group_source_from_sockptr(struct group_source_req *greqs,
  		sockptr_t optval, int optlen)

  {
  	if (in_compat_syscall()) {
  		struct compat_group_source_req gr32;
  
  		if (optlen < sizeof(gr32))
  			return -EINVAL;

  		if (copy_from_sockptr(&gr32, optval, sizeof(gr32)))

  			return -EFAULT;
  		greqs->gsr_interface = gr32.gsr_interface;
  		greqs->gsr_group = gr32.gsr_group;
  		greqs->gsr_source = gr32.gsr_source;
  	} else {
  		if (optlen < sizeof(*greqs))
  			return -EINVAL;

  		if (copy_from_sockptr(greqs, optval, sizeof(*greqs)))

  			return -EFAULT;
  	}
  
  	return 0;
  }

  static int do_ipv6_mcast_group_source(struct sock *sk, int optname,

  		sockptr_t optval, int optlen)

  {

  	struct group_source_req greqs;

  	int omode, add;

  	int ret;

  	ret = copy_group_source_from_sockptr(&greqs, optval, optlen);

  	if (ret)
  		return ret;

  	if (greqs.gsr_group.ss_family != AF_INET6 ||
  	    greqs.gsr_source.ss_family != AF_INET6)

  		return -EADDRNOTAVAIL;
  
  	if (optname == MCAST_BLOCK_SOURCE) {
  		omode = MCAST_EXCLUDE;
  		add = 1;
  	} else if (optname == MCAST_UNBLOCK_SOURCE) {
  		omode = MCAST_EXCLUDE;
  		add = 0;
  	} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
  		struct sockaddr_in6 *psin6;
  		int retv;

  		psin6 = (struct sockaddr_in6 *)&greqs.gsr_group;
  		retv = ipv6_sock_mc_join_ssm(sk, greqs.gsr_interface,

  					     &psin6->sin6_addr,
  					     MCAST_INCLUDE);
  		/* prior join w/ different source is ok */
  		if (retv && retv != -EADDRINUSE)
  			return retv;
  		omode = MCAST_INCLUDE;
  		add = 1;
  	} else /* MCAST_LEAVE_SOURCE_GROUP */ {
  		omode = MCAST_INCLUDE;
  		add = 0;
  	}

  	return ip6_mc_source(add, omode, sk, &greqs);

  }

  static int ipv6_set_mcast_msfilter(struct sock *sk, sockptr_t optval,

  		int optlen)
  {
  	struct group_filter *gsf;
  	int ret;
  
  	if (optlen < GROUP_FILTER_SIZE(0))
  		return -EINVAL;
  	if (optlen > sysctl_optmem_max)
  		return -ENOBUFS;

  	gsf = memdup_sockptr(optval, optlen);

  	if (IS_ERR(gsf))
  		return PTR_ERR(gsf);
  
  	/* numsrc >= (4G-140)/128 overflow in 32 bits */
  	ret = -ENOBUFS;
  	if (gsf->gf_numsrc >= 0x1ffffffU ||
  	    gsf->gf_numsrc > sysctl_mld_max_msf)
  		goto out_free_gsf;
  
  	ret = -EINVAL;
  	if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen)
  		goto out_free_gsf;
  
  	ret = ip6_mc_msfilter(sk, gsf, gsf->gf_slist);
  out_free_gsf:
  	kfree(gsf);
  	return ret;
  }

  static int compat_ipv6_set_mcast_msfilter(struct sock *sk, sockptr_t optval,

  		int optlen)
  {
  	const int size0 = offsetof(struct compat_group_filter, gf_slist);
  	struct compat_group_filter *gf32;
  	void *p;
  	int ret;
  	int n;
  
  	if (optlen < size0)
  		return -EINVAL;
  	if (optlen > sysctl_optmem_max - 4)
  		return -ENOBUFS;
  
  	p = kmalloc(optlen + 4, GFP_KERNEL);
  	if (!p)
  		return -ENOMEM;
  
  	gf32 = p + 4; /* we want ->gf_group and ->gf_slist aligned */
  	ret = -EFAULT;

  	if (copy_from_sockptr(gf32, optval, optlen))

  		goto out_free_p;
  
  	/* numsrc >= (4G-140)/128 overflow in 32 bits */
  	ret = -ENOBUFS;
  	n = gf32->gf_numsrc;
  	if (n >= 0x1ffffffU || n > sysctl_mld_max_msf)
  		goto out_free_p;
  
  	ret = -EINVAL;
  	if (offsetof(struct compat_group_filter, gf_slist[n]) > optlen)
  		goto out_free_p;

  	ret = ip6_mc_msfilter(sk, &(struct group_filter){
  			.gf_interface = gf32->gf_interface,
  			.gf_group = gf32->gf_group,
  			.gf_fmode = gf32->gf_fmode,
  			.gf_numsrc = gf32->gf_numsrc}, gf32->gf_slist);

  
  out_free_p:
  	kfree(p);
  	return ret;
  }

  static int ipv6_mcast_join_leave(struct sock *sk, int optname,

  		sockptr_t optval, int optlen)

  {
  	struct sockaddr_in6 *psin6;
  	struct group_req greq;
  
  	if (optlen < sizeof(greq))
  		return -EINVAL;

  	if (copy_from_sockptr(&greq, optval, sizeof(greq)))

  		return -EFAULT;
  
  	if (greq.gr_group.ss_family != AF_INET6)
  		return -EADDRNOTAVAIL;
  	psin6 = (struct sockaddr_in6 *)&greq.gr_group;
  	if (optname == MCAST_JOIN_GROUP)
  		return ipv6_sock_mc_join(sk, greq.gr_interface,
  					 &psin6->sin6_addr);
  	return ipv6_sock_mc_drop(sk, greq.gr_interface, &psin6->sin6_addr);
  }

  static int compat_ipv6_mcast_join_leave(struct sock *sk, int optname,

  		sockptr_t optval, int optlen)

  {
  	struct compat_group_req gr32;
  	struct sockaddr_in6 *psin6;

  
  	if (optlen < sizeof(gr32))
  		return -EINVAL;

  	if (copy_from_sockptr(&gr32, optval, sizeof(gr32)))

  		return -EFAULT;
  
  	if (gr32.gr_group.ss_family != AF_INET6)
  		return -EADDRNOTAVAIL;

  	psin6 = (struct sockaddr_in6 *)&gr32.gr_group;
  	if (optname == MCAST_JOIN_GROUP)

  		return ipv6_sock_mc_join(sk, gr32.gr_interface,

  					&psin6->sin6_addr);

  	return ipv6_sock_mc_drop(sk, gr32.gr_interface, &psin6->sin6_addr);

  }

  static int ipv6_set_opt_hdr(struct sock *sk, int optname, sockptr_t optval,

  		int optlen)
  {
  	struct ipv6_pinfo *np = inet6_sk(sk);
  	struct ipv6_opt_hdr *new = NULL;
  	struct net *net = sock_net(sk);
  	struct ipv6_txoptions *opt;
  	int err;
  
  	/* hop-by-hop / destination options are privileged option */
  	if (optname != IPV6_RTHDR && !ns_capable(net->user_ns, CAP_NET_RAW))
  		return -EPERM;
  
  	/* remove any sticky options header with a zero option
  	 * length, per RFC3542.
  	 */
  	if (optlen > 0) {

  		if (sockptr_is_null(optval))

  			return -EINVAL;
  		if (optlen < sizeof(struct ipv6_opt_hdr) ||
  		    optlen & 0x7 ||
  		    optlen > 8 * 255)
  			return -EINVAL;

  		new = memdup_sockptr(optval, optlen);

  		if (IS_ERR(new))
  			return PTR_ERR(new);
  		if (unlikely(ipv6_optlen(new) > optlen)) {
  			kfree(new);
  			return -EINVAL;
  		}
  	}
  
  	opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
  	opt = ipv6_renew_options(sk, opt, optname, new);
  	kfree(new);
  	if (IS_ERR(opt))
  		return PTR_ERR(opt);
  
  	/* routing header option needs extra check */
  	err = -EINVAL;
  	if (optname == IPV6_RTHDR && opt && opt->srcrt) {
  		struct ipv6_rt_hdr *rthdr = opt->srcrt;
  		switch (rthdr->type) {
  #if IS_ENABLED(CONFIG_IPV6_MIP6)
  		case IPV6_SRCRT_TYPE_2:
  			if (rthdr->hdrlen != 2 || rthdr->segments_left != 1)
  				goto sticky_done;
  			break;
  #endif
  		case IPV6_SRCRT_TYPE_4:
  		{
  			struct ipv6_sr_hdr *srh =
  				(struct ipv6_sr_hdr *)opt->srcrt;
  
  			if (!seg6_validate_srh(srh, optlen, false))
  				goto sticky_done;
  			break;
  		}
  		default:
  			goto sticky_done;
  		}
  	}
  
  	err = 0;
  	opt = ipv6_update_options(sk, opt);
  sticky_done:
  	if (opt) {
  		atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
  		txopt_put(opt);
  	}
  	return err;
  }

  static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,

  		   sockptr_t optval, unsigned int optlen)

  {
  	struct ipv6_pinfo *np = inet6_sk(sk);

  	struct net *net = sock_net(sk);

  	int val, valbool;
  	int retv = -ENOPROTOOPT;

  	bool needs_rtnl = setsockopt_needs_rtnl(optname);

  	if (sockptr_is_null(optval))

  		val = 0;

  	else {
  		if (optlen >= sizeof(int)) {

  			if (copy_from_sockptr(&val, optval, sizeof(val)))

  				return -EFAULT;
  		} else
  			val = 0;
  	}

  	valbool = (val != 0);

  	if (ip6_mroute_opt(optname))

  		return ip6_mroute_setsockopt(sk, optname, optval, optlen);

  	if (needs_rtnl)
  		rtnl_lock();

  	lock_sock(sk);
  
  	switch (optname) {
  
  	case IPV6_ADDRFORM:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		if (val == PF_INET) {
  			struct ipv6_txoptions *opt;
  			struct sk_buff *pktopt;

  			if (sk->sk_type == SOCK_RAW)
  				break;

  			if (sk->sk_protocol == IPPROTO_UDP ||
  			    sk->sk_protocol == IPPROTO_UDPLITE) {
  				struct udp_sock *up = udp_sk(sk);
  				if (up->pending == AF_INET6) {
  					retv = -EBUSY;
  					break;
  				}

  			} else if (sk->sk_protocol == IPPROTO_TCP) {
  				if (sk->sk_prot != &tcpv6_prot) {
  					retv = -EBUSY;
  					break;
  				}
  			} else {

  				break;
  			}

  			if (sk->sk_state != TCP_ESTABLISHED) {
  				retv = -ENOTCONN;
  				break;
  			}
  
  			if (ipv6_only_sock(sk) ||

  			    !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) {

  				retv = -EADDRNOTAVAIL;
  				break;
  			}
  
  			fl6_free_socklist(sk);

  			__ipv6_sock_mc_close(sk);

  			__ipv6_sock_ac_close(sk);

  			/*
  			 * Sock is moving from IPv6 to IPv4 (sk_prot), so
  			 * remove it from the refcnt debug socks count in the
  			 * original family...
  			 */
  			sk_refcnt_debug_dec(sk);

  			if (sk->sk_protocol == IPPROTO_TCP) {

  				struct inet_connection_sock *icsk = inet_csk(sk);

  				local_bh_disable();

  				sock_prot_inuse_add(net, sk->sk_prot, -1);
  				sock_prot_inuse_add(net, &tcp_prot, 1);

  				local_bh_enable();
  				sk->sk_prot = &tcp_prot;

  				icsk->icsk_af_ops = &ipv4_specific;

  				sk->sk_socket->ops = &inet_stream_ops;
  				sk->sk_family = PF_INET;

  				tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);

  			} else {

  				struct proto *prot = &udp_prot;

  				if (sk->sk_protocol == IPPROTO_UDPLITE)

  					prot = &udplite_prot;

  				local_bh_disable();

  				sock_prot_inuse_add(net, sk->sk_prot, -1);
  				sock_prot_inuse_add(net, prot, 1);

  				local_bh_enable();

  				sk->sk_prot = prot;

  				sk->sk_socket->ops = &inet_dgram_ops;
  				sk->sk_family = PF_INET;
  			}

  			opt = xchg((__force struct ipv6_txoptions **)&np->opt,
  				   NULL);
  			if (opt) {
  				atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
  				txopt_put(opt);
  			}

  			pktopt = xchg(&np->pktoptions, NULL);

  			kfree_skb(pktopt);

  			/*
  			 * ... and add it to the refcnt debug socks count
  			 * in the new family. -acme
  			 */
  			sk_refcnt_debug_inc(sk);

  			module_put(THIS_MODULE);
  			retv = 0;
  			break;
  		}
  		goto e_inval;
  
  	case IPV6_V6ONLY:

  		if (optlen < sizeof(int) ||

  		    inet_sk(sk)->inet_num)

  			goto e_inval;

  		sk->sk_ipv6only = valbool;

  		retv = 0;
  		break;

  	case IPV6_RECVPKTINFO:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		np->rxopt.bits.rxinfo = valbool;
  		retv = 0;
  		break;

  	case IPV6_2292PKTINFO:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		np->rxopt.bits.rxoinfo = valbool;
  		retv = 0;
  		break;

  	case IPV6_RECVHOPLIMIT:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		np->rxopt.bits.rxhlim = valbool;
  		retv = 0;
  		break;

  	case IPV6_2292HOPLIMIT:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		np->rxopt.bits.rxohlim = valbool;
  		retv = 0;
  		break;
  
  	case IPV6_RECVRTHDR:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		np->rxopt.bits.srcrt = valbool;

  		retv = 0;
  		break;

  	case IPV6_2292RTHDR:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		np->rxopt.bits.osrcrt = valbool;

  		retv = 0;
  		break;
  
  	case IPV6_RECVHOPOPTS:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		np->rxopt.bits.hopopts = valbool;
  		retv = 0;
  		break;

  	case IPV6_2292HOPOPTS:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		np->rxopt.bits.ohopopts = valbool;
  		retv = 0;
  		break;
  
  	case IPV6_RECVDSTOPTS:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		np->rxopt.bits.dstopts = valbool;
  		retv = 0;
  		break;

  	case IPV6_2292DSTOPTS:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		np->rxopt.bits.odstopts = valbool;
  		retv = 0;
  		break;

  	case IPV6_TCLASS:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		if (val < -1 || val > 0xff)

  			goto e_inval;

  		/* RFC 3542, 6.5: default traffic class of 0x0 */
  		if (val == -1)
  			val = 0;

  		np->tclass = val;
  		retv = 0;
  		break;

  	case IPV6_RECVTCLASS:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		np->rxopt.bits.rxtclass = valbool;
  		retv = 0;
  		break;

  	case IPV6_FLOWINFO:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		np->rxopt.bits.rxflow = valbool;
  		retv = 0;
  		break;

  	case IPV6_RECVPATHMTU:
  		if (optlen < sizeof(int))
  			goto e_inval;
  		np->rxopt.bits.rxpmtu = valbool;
  		retv = 0;
  		break;

  	case IPV6_TRANSPARENT:

  		if (valbool && !ns_capable(net->user_ns, CAP_NET_RAW) &&
  		    !ns_capable(net->user_ns, CAP_NET_ADMIN)) {

  			retv = -EPERM;
  			break;
  		}

  		if (optlen < sizeof(int))
  			goto e_inval;
  		/* we don't have a separate transparent bit for IPV6 we use the one in the IPv4 socket */
  		inet_sk(sk)->transparent = valbool;
  		retv = 0;
  		break;

  	case IPV6_FREEBIND:
  		if (optlen < sizeof(int))
  			goto e_inval;
  		/* we also don't have a separate freebind bit for IPV6 */
  		inet_sk(sk)->freebind = valbool;
  		retv = 0;
  		break;

  	case IPV6_RECVORIGDSTADDR:
  		if (optlen < sizeof(int))
  			goto e_inval;
  		np->rxopt.bits.rxorigdstaddr = valbool;
  		retv = 0;
  		break;

  	case IPV6_HOPOPTS:
  	case IPV6_RTHDRDSTOPTS:
  	case IPV6_RTHDR:
  	case IPV6_DSTOPTS:

  		retv = ipv6_set_opt_hdr(sk, optname, optval, optlen);

  		break;

  	case IPV6_PKTINFO:
  	{
  		struct in6_pktinfo pkt;
  
  		if (optlen == 0)
  			goto e_inval;

  		else if (optlen < sizeof(struct in6_pktinfo) ||
  			 sockptr_is_null(optval))

  			goto e_inval;

  		if (copy_from_sockptr(&pkt, optval, sizeof(pkt))) {
  			retv = -EFAULT;
  			break;

  		}

  		if (!sk_dev_equal_l3scope(sk, pkt.ipi6_ifindex))

  			goto e_inval;
  
  		np->sticky_pktinfo.ipi6_ifindex = pkt.ipi6_ifindex;

  		np->sticky_pktinfo.ipi6_addr = pkt.ipi6_addr;

  		retv = 0;
  		break;
  	}

  	case IPV6_2292PKTOPTIONS:

  	{
  		struct ipv6_txoptions *opt = NULL;
  		struct msghdr msg;

  		struct flowi6 fl6;

  		struct ipcm6_cookie ipc6;

  		memset(&fl6, 0, sizeof(fl6));
  		fl6.flowi6_oif = sk->sk_bound_dev_if;
  		fl6.flowi6_mark = sk->sk_mark;

  
  		if (optlen == 0)
  			goto update;
  
  		/* 1K is probably excessive
  		 * 1K is surely not enough, 2K per standard header is 16K.
  		 */
  		retv = -EINVAL;
  		if (optlen > 64*1024)
  			break;
  
  		opt = sock_kmalloc(sk, sizeof(*opt) + optlen, GFP_KERNEL);
  		retv = -ENOBUFS;

  		if (!opt)

  			break;
  
  		memset(opt, 0, sizeof(*opt));

  		refcount_set(&opt->refcnt, 1);

  		opt->tot_len = sizeof(*opt) + optlen;
  		retv = -EFAULT;

  		if (copy_from_sockptr(opt + 1, optval, optlen))

  			goto done;
  
  		msg.msg_controllen = optlen;

  		msg.msg_control = (void *)(opt+1);

  		ipc6.opt = opt;

  		retv = ip6_datagram_send_ctl(net, sk, &msg, &fl6, &ipc6);

  		if (retv)
  			goto done;
  update:
  		retv = 0;

  		opt = ipv6_update_options(sk, opt);

  done:

  		if (opt) {
  			atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
  			txopt_put(opt);
  		}

  		break;
  	}
  	case IPV6_UNICAST_HOPS:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		if (val > 255 || val < -1)
  			goto e_inval;
  		np->hop_limit = val;
  		retv = 0;
  		break;
  
  	case IPV6_MULTICAST_HOPS:
  		if (sk->sk_type == SOCK_STREAM)

  			break;

  		if (optlen < sizeof(int))
  			goto e_inval;

  		if (val > 255 || val < -1)
  			goto e_inval;

  		np->mcast_hops = (val == -1 ? IPV6_DEFAULT_MCASTHOPS : val);

  		retv = 0;
  		break;
  
  	case IPV6_MULTICAST_LOOP:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		if (val != valbool)
  			goto e_inval;

  		np->mc_loop = valbool;
  		retv = 0;
  		break;

  	case IPV6_UNICAST_IF:
  	{
  		struct net_device *dev = NULL;
  		int ifindex;
  
  		if (optlen != sizeof(int))
  			goto e_inval;
  
  		ifindex = (__force int)ntohl((__force __be32)val);
  		if (ifindex == 0) {
  			np->ucast_oif = 0;
  			retv = 0;
  			break;
  		}
  
  		dev = dev_get_by_index(net, ifindex);
  		retv = -EADDRNOTAVAIL;
  		if (!dev)
  			break;
  		dev_put(dev);
  
  		retv = -EINVAL;
  		if (sk->sk_bound_dev_if)
  			break;
  
  		np->ucast_oif = ifindex;
  		retv = 0;
  		break;
  	}

  	case IPV6_MULTICAST_IF:
  		if (sk->sk_type == SOCK_STREAM)

  			break;

  		if (optlen < sizeof(int))
  			goto e_inval;

  		if (val) {

  			struct net_device *dev;

  			int midx;

  			rcu_read_lock();

  			dev = dev_get_by_index_rcu(net, val);

  			if (!dev) {

  				rcu_read_unlock();

  				retv = -ENODEV;
  				break;
  			}

  			midx = l3mdev_master_ifindex_rcu(dev);
  
  			rcu_read_unlock();
  
  			if (sk->sk_bound_dev_if &&
  			    sk->sk_bound_dev_if != val &&
  			    (!midx || midx != sk->sk_bound_dev_if))
  				goto e_inval;

  		}
  		np->mcast_oif = val;
  		retv = 0;
  		break;
  	case IPV6_ADD_MEMBERSHIP:
  	case IPV6_DROP_MEMBERSHIP:
  	{
  		struct ipv6_mreq mreq;

  		if (optlen < sizeof(struct ipv6_mreq))
  			goto e_inval;

  		retv = -EPROTO;
  		if (inet_sk(sk)->is_icsk)
  			break;

  		retv = -EFAULT;

  		if (copy_from_sockptr(&mreq, optval, sizeof(struct ipv6_mreq)))

  			break;
  
  		if (optname == IPV6_ADD_MEMBERSHIP)

  			retv = ipv6_sock_mc_join(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr);

  		else

  			retv = ipv6_sock_mc_drop(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_multiaddr);

  		break;
  	}
  	case IPV6_JOIN_ANYCAST:
  	case IPV6_LEAVE_ANYCAST:
  	{
  		struct ipv6_mreq mreq;

  		if (optlen < sizeof(struct ipv6_mreq))

  			goto e_inval;
  
  		retv = -EFAULT;

  		if (copy_from_sockptr(&mreq, optval, sizeof(struct ipv6_mreq)))

  			break;
  
  		if (optname == IPV6_JOIN_ANYCAST)
  			retv = ipv6_sock_ac_join(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_acaddr);
  		else
  			retv = ipv6_sock_ac_drop(sk, mreq.ipv6mr_ifindex, &mreq.ipv6mr_acaddr);
  		break;
  	}

  	case IPV6_MULTICAST_ALL:
  		if (optlen < sizeof(int))
  			goto e_inval;
  		np->mc_all = valbool;
  		retv = 0;
  		break;

  	case MCAST_JOIN_GROUP:
  	case MCAST_LEAVE_GROUP:

  		if (in_compat_syscall())
  			retv = compat_ipv6_mcast_join_leave(sk, optname, optval,
  							    optlen);
  		else
  			retv = ipv6_mcast_join_leave(sk, optname, optval,
  						     optlen);

  		break;

  	case MCAST_JOIN_SOURCE_GROUP:
  	case MCAST_LEAVE_SOURCE_GROUP:
  	case MCAST_BLOCK_SOURCE:
  	case MCAST_UNBLOCK_SOURCE:

  		retv = do_ipv6_mcast_group_source(sk, optname, optval, optlen);

  		break;

  	case MCAST_MSFILTER:

  		if (in_compat_syscall())
  			retv = compat_ipv6_set_mcast_msfilter(sk, optval,
  							      optlen);
  		else
  			retv = ipv6_set_mcast_msfilter(sk, optval, optlen);

  		break;

  	case IPV6_ROUTER_ALERT:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		retv = ip6_ra_control(sk, val);

  		break;

  	case IPV6_ROUTER_ALERT_ISOLATE:
  		if (optlen < sizeof(int))
  			goto e_inval;
  		np->rtalert_isolate = valbool;
  		retv = 0;
  		break;

  	case IPV6_MTU_DISCOVER:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		if (val < IPV6_PMTUDISC_DONT || val > IPV6_PMTUDISC_OMIT)

  			goto e_inval;
  		np->pmtudisc = val;
  		retv = 0;
  		break;
  	case IPV6_MTU:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		if (val && val < IPV6_MIN_MTU)
  			goto e_inval;
  		np->frag_size = val;
  		retv = 0;
  		break;
  	case IPV6_RECVERR:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		np->recverr = valbool;
  		if (!val)
  			skb_queue_purge(&sk->sk_error_queue);
  		retv = 0;
  		break;
  	case IPV6_FLOWINFO_SEND:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		np->sndflow = valbool;
  		retv = 0;
  		break;
  	case IPV6_FLOWLABEL_MGR:

  		retv = ipv6_flowlabel_opt(sk, optval, optlen);

  		break;
  	case IPV6_IPSEC_POLICY:
  	case IPV6_XFRM_POLICY:

  		retv = -EPERM;

  		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))

  			break;

  		retv = xfrm_user_policy(sk, optname, optval, optlen);

  		break;

  	case IPV6_ADDR_PREFERENCES:

  		if (optlen < sizeof(int))
  			goto e_inval;

  		retv = __ip6_sock_set_addr_preferences(sk, val);

  		break;

  	case IPV6_MINHOPCOUNT:
  		if (optlen < sizeof(int))
  			goto e_inval;
  		if (val < 0 || val > 255)
  			goto e_inval;
  		np->min_hopcount = val;

  		retv = 0;

  		break;
  	case IPV6_DONTFRAG:
  		np->dontfrag = valbool;

  		retv = 0;
  		break;

  	case IPV6_AUTOFLOWLABEL:
  		np->autoflowlabel = valbool;

  		np->autoflowlabel_set = 1;

  		retv = 0;
  		break;

  	case IPV6_RECVFRAGSIZE:
  		np->rxopt.bits.recvfragsize = valbool;
  		retv = 0;
  		break;

  	case IPV6_RECVERR_RFC4884:
  		if (optlen < sizeof(int))
  			goto e_inval;
  		if (val < 0 || val > 1)
  			goto e_inval;
  		np->recverr_rfc4884 = valbool;
  		retv = 0;
  		break;

  	}

  	release_sock(sk);

  	if (needs_rtnl)
  		rtnl_unlock();

  	return retv;
  
  e_inval:
  	release_sock(sk);

  	if (needs_rtnl)
  		rtnl_unlock();

  	return -EINVAL;
  }

  int ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
  		    unsigned int optlen)

  {
  	int err;
  
  	if (level == SOL_IP && sk->sk_type != SOCK_RAW)
  		return udp_prot.setsockopt(sk, level, optname, optval, optlen);
  
  	if (level != SOL_IPV6)
  		return -ENOPROTOOPT;

  	err = do_ipv6_setsockopt(sk, level, optname, optval, optlen);

  #ifdef CONFIG_NETFILTER
  	/* we need to exclude all possible ENOPROTOOPTs except default case */
  	if (err == -ENOPROTOOPT && optname != IPV6_IPSEC_POLICY &&

  			optname != IPV6_XFRM_POLICY)

  		err = nf_setsockopt(sk, PF_INET6, optname, optval, optlen);

  #endif
  	return err;
  }

  EXPORT_SYMBOL(ipv6_setsockopt);

  static int ipv6_getsockopt_sticky(struct sock *sk, struct ipv6_txoptions *opt,

  				  int optname, char __user *optval, int len)

  {

  	struct ipv6_opt_hdr *hdr;

  	if (!opt)
  		return 0;

  	switch (optname) {

  	case IPV6_HOPOPTS:
  		hdr = opt->hopopt;
  		break;
  	case IPV6_RTHDRDSTOPTS:
  		hdr = opt->dst0opt;
  		break;
  	case IPV6_RTHDR:
  		hdr = (struct ipv6_opt_hdr *)opt->srcrt;
  		break;
  	case IPV6_DSTOPTS:
  		hdr = opt->dst1opt;
  		break;
  	default:
  		return -EINVAL;	/* should not happen */
  	}
  
  	if (!hdr)

  		return 0;

  	len = min_t(unsigned int, len, ipv6_optlen(hdr));

  	if (copy_to_user(optval, hdr, len))

  		return -EFAULT;

  	return len;

  }

  static int ipv6_get_msfilter(struct sock *sk, void __user *optval,
  		int __user *optlen, int len)
  {
  	const int size0 = offsetof(struct group_filter, gf_slist);
  	struct group_filter __user *p = optval;
  	struct group_filter gsf;
  	int num;
  	int err;
  
  	if (len < size0)
  		return -EINVAL;
  	if (copy_from_user(&gsf, p, size0))
  		return -EFAULT;
  	if (gsf.gf_group.ss_family != AF_INET6)
  		return -EADDRNOTAVAIL;
  	num = gsf.gf_numsrc;
  	lock_sock(sk);
  	err = ip6_mc_msfget(sk, &gsf, p->gf_slist);
  	if (!err) {
  		if (num > gsf.gf_numsrc)
  			num = gsf.gf_numsrc;
  		if (put_user(GROUP_FILTER_SIZE(num), optlen) ||
  		    copy_to_user(p, &gsf, size0))
  			err = -EFAULT;
  	}
  	release_sock(sk);
  	return err;
  }

  static int compat_ipv6_get_msfilter(struct sock *sk, void __user *optval,
  		int __user *optlen)
  {
  	const int size0 = offsetof(struct compat_group_filter, gf_slist);
  	struct compat_group_filter __user *p = optval;
  	struct compat_group_filter gf32;
  	struct group_filter gf;
  	int len, err;
  	int num;
  
  	if (get_user(len, optlen))
  		return -EFAULT;
  	if (len < size0)
  		return -EINVAL;
  
  	if (copy_from_user(&gf32, p, size0))
  		return -EFAULT;
  	gf.gf_interface = gf32.gf_interface;
  	gf.gf_fmode = gf32.gf_fmode;
  	num = gf.gf_numsrc = gf32.gf_numsrc;
  	gf.gf_group = gf32.gf_group;
  
  	if (gf.gf_group.ss_family != AF_INET6)
  		return -EADDRNOTAVAIL;
  
  	lock_sock(sk);
  	err = ip6_mc_msfget(sk, &gf, p->gf_slist);
  	release_sock(sk);
  	if (err)
  		return err;
  	if (num > gf.gf_numsrc)
  		num = gf.gf_numsrc;
  	len = GROUP_FILTER_SIZE(num) - (sizeof(gf)-sizeof(gf32));
  	if (put_user(len, optlen) ||
  	    put_user(gf.gf_fmode, &p->gf_fmode) ||
  	    put_user(gf.gf_numsrc, &p->gf_numsrc))
  		return -EFAULT;
  	return 0;
  }

  static int do_ipv6_getsockopt(struct sock *sk, int level, int optname,

  		    char __user *optval, int __user *optlen, unsigned int flags)

  {
  	struct ipv6_pinfo *np = inet6_sk(sk);
  	int len;
  	int val;

  	if (ip6_mroute_opt(optname))
  		return ip6_mroute_getsockopt(sk, optname, optval, optlen);

  	if (get_user(len, optlen))
  		return -EFAULT;
  	switch (optname) {
  	case IPV6_ADDRFORM:
  		if (sk->sk_protocol != IPPROTO_UDP &&

  		    sk->sk_protocol != IPPROTO_UDPLITE &&

  		    sk->sk_protocol != IPPROTO_TCP)

  			return -ENOPROTOOPT;

  		if (sk->sk_state != TCP_ESTABLISHED)
  			return -ENOTCONN;
  		val = sk->sk_family;
  		break;
  	case MCAST_MSFILTER:

  		if (in_compat_syscall())
  			return compat_ipv6_get_msfilter(sk, optval, optlen);

  		return ipv6_get_msfilter(sk, optval, optlen, len);

  	case IPV6_2292PKTOPTIONS:

  	{
  		struct msghdr msg;
  		struct sk_buff *skb;
  
  		if (sk->sk_type != SOCK_STREAM)
  			return -ENOPROTOOPT;
  
  		msg.msg_control = optval;
  		msg.msg_controllen = len;

  		msg.msg_flags = flags;

  		msg.msg_control_is_user = true;

  
  		lock_sock(sk);
  		skb = np->pktoptions;
  		if (skb)

  			ip6_datagram_recv_ctl(sk, &msg, skb);

  		release_sock(sk);
  		if (!skb) {

  			if (np->rxopt.bits.rxinfo) {
  				struct in6_pktinfo src_info;

  				src_info.ipi6_ifindex = np->mcast_oif ? np->mcast_oif :
  					np->sticky_pktinfo.ipi6_ifindex;

  				src_info.ipi6_addr = np->mcast_oif ? sk->sk_v6_daddr : np->sticky_pktinfo.ipi6_addr;

  				put_cmsg(&msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
  			}
  			if (np->rxopt.bits.rxhlim) {
  				int hlim = np->mcast_hops;
  				put_cmsg(&msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
  			}

  			if (np->rxopt.bits.rxtclass) {

  				int tclass = (int)ip6_tclass(np->rcv_flowinfo);

  				put_cmsg(&msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
  			}

  			if (np->rxopt.bits.rxoinfo) {
  				struct in6_pktinfo src_info;

  				src_info.ipi6_ifindex = np->mcast_oif ? np->mcast_oif :
  					np->sticky_pktinfo.ipi6_ifindex;

  				src_info.ipi6_addr = np->mcast_oif ? sk->sk_v6_daddr :
  								     np->sticky_pktinfo.ipi6_addr;

  				put_cmsg(&msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
  			}
  			if (np->rxopt.bits.rxohlim) {
  				int hlim = np->mcast_hops;
  				put_cmsg(&msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
  			}

  			if (np->rxopt.bits.rxflow) {

  				__be32 flowinfo = np->rcv_flowinfo;

  				put_cmsg(&msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
  			}

  		}
  		len -= msg.msg_controllen;
  		return put_user(len, optlen);
  	}
  	case IPV6_MTU:
  	{
  		struct dst_entry *dst;

  		val = 0;

  		rcu_read_lock();
  		dst = __sk_dst_get(sk);
  		if (dst)

  			val = dst_mtu(dst);

  		rcu_read_unlock();

  		if (!val)
  			return -ENOTCONN;
  		break;
  	}
  
  	case IPV6_V6ONLY:

  		val = sk->sk_ipv6only;

  		break;

  	case IPV6_RECVPKTINFO:

  		val = np->rxopt.bits.rxinfo;
  		break;

  	case IPV6_2292PKTINFO:
  		val = np->rxopt.bits.rxoinfo;
  		break;
  
  	case IPV6_RECVHOPLIMIT:

  		val = np->rxopt.bits.rxhlim;
  		break;

  	case IPV6_2292HOPLIMIT:
  		val = np->rxopt.bits.rxohlim;
  		break;
  
  	case IPV6_RECVRTHDR:

  		val = np->rxopt.bits.srcrt;
  		break;

  	case IPV6_2292RTHDR:
  		val = np->rxopt.bits.osrcrt;
  		break;

  	case IPV6_HOPOPTS:

  	case IPV6_RTHDRDSTOPTS:
  	case IPV6_RTHDR:
  	case IPV6_DSTOPTS:
  	{

  		struct ipv6_txoptions *opt;

  
  		lock_sock(sk);

  		opt = rcu_dereference_protected(np->opt,
  						lockdep_sock_is_held(sk));

  		len = ipv6_getsockopt_sticky(sk, opt, optname, optval, len);

  		release_sock(sk);

  		/* check if ipv6_getsockopt_sticky() returns err code */
  		if (len < 0)
  			return len;

  		return put_user(len, optlen);
  	}
  
  	case IPV6_RECVHOPOPTS:

  		val = np->rxopt.bits.hopopts;
  		break;

  	case IPV6_2292HOPOPTS:
  		val = np->rxopt.bits.ohopopts;
  		break;
  
  	case IPV6_RECVDSTOPTS:

  		val = np->rxopt.bits.dstopts;
  		break;

  	case IPV6_2292DSTOPTS:
  		val = np->rxopt.bits.odstopts;
  		break;

  	case IPV6_TCLASS:
  		val = np->tclass;
  		break;
  
  	case IPV6_RECVTCLASS:
  		val = np->rxopt.bits.rxtclass;
  		break;

  	case IPV6_FLOWINFO:
  		val = np->rxopt.bits.rxflow;
  		break;

  	case IPV6_RECVPATHMTU:
  		val = np->rxopt.bits.rxpmtu;
  		break;
  
  	case IPV6_PATHMTU:
  	{
  		struct dst_entry *dst;
  		struct ip6_mtuinfo mtuinfo;
  
  		if (len < sizeof(mtuinfo))
  			return -EINVAL;
  
  		len = sizeof(mtuinfo);
  		memset(&mtuinfo, 0, sizeof(mtuinfo));
  
  		rcu_read_lock();
  		dst = __sk_dst_get(sk);
  		if (dst)
  			mtuinfo.ip6m_mtu = dst_mtu(dst);
  		rcu_read_unlock();
  		if (!mtuinfo.ip6m_mtu)
  			return -ENOTCONN;
  
  		if (put_user(len, optlen))
  			return -EFAULT;
  		if (copy_to_user(optval, &mtuinfo, len))
  			return -EFAULT;
  
  		return 0;

  	}

  	case IPV6_TRANSPARENT:
  		val = inet_sk(sk)->transparent;
  		break;

  	case IPV6_FREEBIND:
  		val = inet_sk(sk)->freebind;
  		break;

  	case IPV6_RECVORIGDSTADDR:
  		val = np->rxopt.bits.rxorigdstaddr;
  		break;

  	case IPV6_UNICAST_HOPS:

  	case IPV6_MULTICAST_HOPS:

  	{
  		struct dst_entry *dst;
  
  		if (optname == IPV6_UNICAST_HOPS)
  			val = np->hop_limit;
  		else
  			val = np->mcast_hops;

  		if (val < 0) {
  			rcu_read_lock();
  			dst = __sk_dst_get(sk);
  			if (dst)

  				val = ip6_dst_hoplimit(dst);

  			rcu_read_unlock();

  		}

  		if (val < 0)

  			val = sock_net(sk)->ipv6.devconf_all->hop_limit;

  		break;

  	}

  
  	case IPV6_MULTICAST_LOOP:
  		val = np->mc_loop;
  		break;
  
  	case IPV6_MULTICAST_IF:
  		val = np->mcast_oif;
  		break;

  	case IPV6_MULTICAST_ALL:
  		val = np->mc_all;
  		break;

  	case IPV6_UNICAST_IF:
  		val = (__force int)htonl((__u32) np->ucast_oif);
  		break;

  	case IPV6_MTU_DISCOVER:
  		val = np->pmtudisc;
  		break;
  
  	case IPV6_RECVERR:
  		val = np->recverr;
  		break;
  
  	case IPV6_FLOWINFO_SEND:
  		val = np->sndflow;
  		break;

  	case IPV6_FLOWLABEL_MGR:
  	{
  		struct in6_flowlabel_req freq;

  		int flags;

  
  		if (len < sizeof(freq))
  			return -EINVAL;
  
  		if (copy_from_user(&freq, optval, sizeof(freq)))
  			return -EFAULT;
  
  		if (freq.flr_action != IPV6_FL_A_GET)
  			return -EINVAL;
  
  		len = sizeof(freq);

  		flags = freq.flr_flags;

  		memset(&freq, 0, sizeof(freq));

  		val = ipv6_flowlabel_opt_get(sk, &freq, flags);

  		if (val < 0)
  			return val;
  
  		if (put_user(len, optlen))
  			return -EFAULT;
  		if (copy_to_user(optval, &freq, len))
  			return -EFAULT;
  
  		return 0;
  	}

  	case IPV6_ADDR_PREFERENCES:
  		val = 0;
  
  		if (np->srcprefs & IPV6_PREFER_SRC_TMP)
  			val |= IPV6_PREFER_SRC_TMP;
  		else if (np->srcprefs & IPV6_PREFER_SRC_PUBLIC)
  			val |= IPV6_PREFER_SRC_PUBLIC;
  		else {
  			/* XXX: should we return system default? */
  			val |= IPV6_PREFER_SRC_PUBTMP_DEFAULT;
  		}
  
  		if (np->srcprefs & IPV6_PREFER_SRC_COA)
  			val |= IPV6_PREFER_SRC_COA;
  		else
  			val |= IPV6_PREFER_SRC_HOME;
  		break;

  
  	case IPV6_MINHOPCOUNT:
  		val = np->min_hopcount;
  		break;

  
  	case IPV6_DONTFRAG:
  		val = np->dontfrag;
  		break;

  	case IPV6_AUTOFLOWLABEL:

  		val = ip6_autoflowlabel(sock_net(sk), np);

  		break;

  	case IPV6_RECVFRAGSIZE:
  		val = np->rxopt.bits.recvfragsize;
  		break;

  	case IPV6_ROUTER_ALERT_ISOLATE:
  		val = np->rtalert_isolate;
  		break;

  	case IPV6_RECVERR_RFC4884:
  		val = np->recverr_rfc4884;
  		break;

  	default:

  		return -ENOPROTOOPT;

  	}
  	len = min_t(unsigned int, sizeof(int), len);

  	if (put_user(len, optlen))

  		return -EFAULT;

  	if (copy_to_user(optval, &val, len))

  		return -EFAULT;
  	return 0;
  }

  int ipv6_getsockopt(struct sock *sk, int level, int optname,
  		    char __user *optval, int __user *optlen)
  {
  	int err;
  
  	if (level == SOL_IP && sk->sk_type != SOCK_RAW)
  		return udp_prot.getsockopt(sk, level, optname, optval, optlen);

  	if (level != SOL_IPV6)

  		return -ENOPROTOOPT;

  	err = do_ipv6_getsockopt(sk, level, optname, optval, optlen, 0);

  #ifdef CONFIG_NETFILTER

  	/* we need to exclude all possible ENOPROTOOPTs except default case */
  	if (err == -ENOPROTOOPT && optname != IPV6_2292PKTOPTIONS) {

  		int len;
  
  		if (get_user(len, optlen))
  			return -EFAULT;

  		err = nf_getsockopt(sk, PF_INET6, optname, optval, &len);

  		if (err >= 0)
  			err = put_user(len, optlen);
  	}
  #endif
  	return err;
  }

  EXPORT_SYMBOL(ipv6_getsockopt);