text: /*
   *	IPv6 BSD socket options interface
   *	Linux INET6 implementation
   *
   *	Authors:
   *	Pedro Roque		<roque@di.fc.ul.pt>
   *
   *	Based on linux/net/ipv4/ip_sockglue.c
   *
   *	This program is free software; you can redistribute it and/or
   *      modify it under the terms of the GNU General Public License
   *      as published by the Free Software Foundation; either version
   *      2 of the License, or (at your option) any later version.
   *
   *	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 <asm/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;
  
  	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 == NULL) {
  		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;
  }
  
  static
  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(&inet6_sk(sk)->opt, opt);
  	} else {
  		spin_lock(&sk->sk_dst_lock);
  		opt = xchg(&inet6_sk(sk)->opt, opt);
  		spin_unlock(&sk->sk_dst_lock);
  	}
  	sk_dst_reset(sk);
  
  	return opt;
  }
  
  static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
  		    char __user *optval, unsigned int optlen)
  {
  	struct ipv6_pinfo *np = inet6_sk(sk);
  	struct net *net = sock_net(sk);
  	int val, valbool;
  	int retv = -ENOPROTOOPT;
  
  	if (optval == NULL)
  		val=0;
  	else {
  		if (optlen >= sizeof(int)) {
  			if (get_user(val, (int __user *) optval))
  				return -EFAULT;
  		} else
  			val = 0;
  	}
  
  	valbool = (val!=0);
  
  	if (ip6_mroute_opt(optname))
  		return ip6_mroute_setsockopt(sk, optname, optval, optlen);
  
  	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)
  				break;
  
  			if (sk->sk_state != TCP_ESTABLISHED) {
  				retv = -ENOTCONN;
  				break;
  			}
  
  			if (ipv6_only_sock(sk) ||
  			    !ipv6_addr_v4mapped(&np->daddr)) {
  				retv = -EADDRNOTAVAIL;
  				break;
  			}
  
  			fl6_free_socklist(sk);
  			ipv6_sock_mc_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(&np->opt, NULL);
  			if (opt)
  				sock_kfree_s(sk, opt, opt->tot_len);
  			pktopt = xchg(&np->pktoptions, NULL);
  			kfree_skb(pktopt);
  
  			sk->sk_destruct = inet_sock_destruct;
  			/*
  			 * ... 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;
  		np->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_ADMIN) &&
  		    !ns_capable(net->user_ns, CAP_NET_RAW)) {
  			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_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:
  	{
  		struct ipv6_txoptions *opt;
  
  		/* remove any sticky options header with a zero option
  		 * length, per RFC3542.
  		 */
  		if (optlen == 0)
  			optval = NULL;
  		else if (optval == NULL)
  			goto e_inval;
  		else if (optlen < sizeof(struct ipv6_opt_hdr) ||
  			 optlen & 0x7 || optlen > 8 * 255)
  			goto e_inval;
  
  		/* hop-by-hop / destination options are privileged option */
  		retv = -EPERM;
  		if (optname != IPV6_RTHDR && !ns_capable(net->user_ns, CAP_NET_RAW))
  			break;
  
  		opt = ipv6_renew_options(sk, np->opt, optname,
  					 (struct ipv6_opt_hdr __user *)optval,
  					 optlen);
  		if (IS_ERR(opt)) {
  			retv = PTR_ERR(opt);
  			break;
  		}
  
  		/* routing header option needs extra check */
  		retv = -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
  			default:
  				goto sticky_done;
  			}
  		}
  
  		retv = 0;
  		opt = ipv6_update_options(sk, opt);
  sticky_done:
  		if (opt)
  			sock_kfree_s(sk, opt, opt->tot_len);
  		break;
  	}
  
  	case IPV6_PKTINFO:
  	{
  		struct in6_pktinfo pkt;
  
  		if (optlen == 0)
  			goto e_inval;
  		else if (optlen < sizeof(struct in6_pktinfo) || optval == NULL)
  			goto e_inval;
  
  		if (copy_from_user(&pkt, optval, sizeof(struct in6_pktinfo))) {
  				retv = -EFAULT;
  				break;
  		}
  		if (sk->sk_bound_dev_if && pkt.ipi6_ifindex != sk->sk_bound_dev_if)
  			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;
  		int junk;
  
  		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 == NULL)
  			break;
  
  		memset(opt, 0, sizeof(*opt));
  		opt->tot_len = sizeof(*opt) + optlen;
  		retv = -EFAULT;
  		if (copy_from_user(opt+1, optval, optlen))
  			goto done;
  
  		msg.msg_controllen = optlen;
  		msg.msg_control = (void*)(opt+1);
  
  		retv = ip6_datagram_send_ctl(net, sk, &msg, &fl6, opt, &junk,
  					     &junk, &junk);
  		if (retv)
  			goto done;
  update:
  		retv = 0;
  		opt = ipv6_update_options(sk, opt);
  done:
  		if (opt)
  			sock_kfree_s(sk, opt, opt->tot_len);
  		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;
  
  			if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != val)
  				goto e_inval;
  
  			dev = dev_get_by_index(net, val);
  			if (!dev) {
  				retv = -ENODEV;
  				break;
  			}
  			dev_put(dev);
  		}
  		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_user(&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_user(&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 MCAST_JOIN_GROUP:
  	case MCAST_LEAVE_GROUP:
  	{
  		struct group_req greq;
  		struct sockaddr_in6 *psin6;
  
  		if (optlen < sizeof(struct group_req))
  			goto e_inval;
  
  		retv = -EFAULT;
  		if (copy_from_user(&greq, optval, sizeof(struct group_req)))
  			break;
  		if (greq.gr_group.ss_family != AF_INET6) {
  			retv = -EADDRNOTAVAIL;
  			break;
  		}
  		psin6 = (struct sockaddr_in6 *)&greq.gr_group;
  		if (optname == MCAST_JOIN_GROUP)
  			retv = ipv6_sock_mc_join(sk, greq.gr_interface,
  				&psin6->sin6_addr);
  		else
  			retv = ipv6_sock_mc_drop(sk, greq.gr_interface,
  				&psin6->sin6_addr);
  		break;
  	}
  	case MCAST_JOIN_SOURCE_GROUP:
  	case MCAST_LEAVE_SOURCE_GROUP:
  	case MCAST_BLOCK_SOURCE:
  	case MCAST_UNBLOCK_SOURCE:
  	{
  		struct group_source_req greqs;
  		int omode, add;
  
  		if (optlen < sizeof(struct group_source_req))
  			goto e_inval;
  		if (copy_from_user(&greqs, optval, sizeof(greqs))) {
  			retv = -EFAULT;
  			break;
  		}
  		if (greqs.gsr_group.ss_family != AF_INET6 ||
  		    greqs.gsr_source.ss_family != AF_INET6) {
  			retv = -EADDRNOTAVAIL;
  			break;
  		}
  		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;
  
  			psin6 = (struct sockaddr_in6 *)&greqs.gsr_group;
  			retv = ipv6_sock_mc_join(sk, greqs.gsr_interface,
  				&psin6->sin6_addr);
  			/* prior join w/ different source is ok */
  			if (retv && retv != -EADDRINUSE)
  				break;
  			omode = MCAST_INCLUDE;
  			add = 1;
  		} else /* MCAST_LEAVE_SOURCE_GROUP */ {
  			omode = MCAST_INCLUDE;
  			add = 0;
  		}
  		retv = ip6_mc_source(add, omode, sk, &greqs);
  		break;
  	}
  	case MCAST_MSFILTER:
  	{
  		struct group_filter *gsf;
  
  		if (optlen < GROUP_FILTER_SIZE(0))
  			goto e_inval;
  		if (optlen > sysctl_optmem_max) {
  			retv = -ENOBUFS;
  			break;
  		}
  		gsf = kmalloc(optlen,GFP_KERNEL);
  		if (!gsf) {
  			retv = -ENOBUFS;
  			break;
  		}
  		retv = -EFAULT;
  		if (copy_from_user(gsf, optval, optlen)) {
  			kfree(gsf);
  			break;
  		}
  		/* numsrc >= (4G-140)/128 overflow in 32 bits */
  		if (gsf->gf_numsrc >= 0x1ffffffU ||
  		    gsf->gf_numsrc > sysctl_mld_max_msf) {
  			kfree(gsf);
  			retv = -ENOBUFS;
  			break;
  		}
  		if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) {
  			kfree(gsf);
  			retv = -EINVAL;
  			break;
  		}
  		retv = ip6_mc_msfilter(sk, gsf);
  		kfree(gsf);
  
  		break;
  	}
  	case IPV6_ROUTER_ALERT:
  		if (optlen < sizeof(int))
  			goto e_inval;
  		retv = ip6_ra_control(sk, val);
  		break;
  	case IPV6_MTU_DISCOVER:
  		if (optlen < sizeof(int))
  			goto e_inval;
  		if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_PROBE)
  			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:
  	    {
  		unsigned int pref = 0;
  		unsigned int prefmask = ~0;
  
  		if (optlen < sizeof(int))
  			goto e_inval;
  
  		retv = -EINVAL;
  
  		/* check PUBLIC/TMP/PUBTMP_DEFAULT conflicts */
  		switch (val & (IPV6_PREFER_SRC_PUBLIC|
  			       IPV6_PREFER_SRC_TMP|
  			       IPV6_PREFER_SRC_PUBTMP_DEFAULT)) {
  		case IPV6_PREFER_SRC_PUBLIC:
  			pref |= IPV6_PREFER_SRC_PUBLIC;
  			break;
  		case IPV6_PREFER_SRC_TMP:
  			pref |= IPV6_PREFER_SRC_TMP;
  			break;
  		case IPV6_PREFER_SRC_PUBTMP_DEFAULT:
  			break;
  		case 0:
  			goto pref_skip_pubtmp;
  		default:
  			goto e_inval;
  		}
  
  		prefmask &= ~(IPV6_PREFER_SRC_PUBLIC|
  			      IPV6_PREFER_SRC_TMP);
  pref_skip_pubtmp:
  
  		/* check HOME/COA conflicts */
  		switch (val & (IPV6_PREFER_SRC_HOME|IPV6_PREFER_SRC_COA)) {
  		case IPV6_PREFER_SRC_HOME:
  			break;
  		case IPV6_PREFER_SRC_COA:
  			pref |= IPV6_PREFER_SRC_COA;
  		case 0:
  			goto pref_skip_coa;
  		default:
  			goto e_inval;
  		}
  
  		prefmask &= ~IPV6_PREFER_SRC_COA;
  pref_skip_coa:
  
  		/* check CGA/NONCGA conflicts */
  		switch (val & (IPV6_PREFER_SRC_CGA|IPV6_PREFER_SRC_NONCGA)) {
  		case IPV6_PREFER_SRC_CGA:
  		case IPV6_PREFER_SRC_NONCGA:
  		case 0:
  			break;
  		default:
  			goto e_inval;
  		}
  
  		np->srcprefs = (np->srcprefs & prefmask) | pref;
  		retv = 0;
  
  		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;
  	}
  
  	release_sock(sk);
  
  	return retv;
  
  e_inval:
  	release_sock(sk);
  	return -EINVAL;
  }
  
  int ipv6_setsockopt(struct sock *sk, int level, int optname,
  		    char __user *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) {
  		lock_sock(sk);
  		err = nf_setsockopt(sk, PF_INET6, optname, optval,
  				optlen);
  		release_sock(sk);
  	}
  #endif
  	return err;
  }
  
  EXPORT_SYMBOL(ipv6_setsockopt);
  
  #ifdef CONFIG_COMPAT
  int compat_ipv6_setsockopt(struct sock *sk, int level, int optname,
  			   char __user *optval, unsigned int optlen)
  {
  	int err;
  
  	if (level == SOL_IP && sk->sk_type != SOCK_RAW) {
  		if (udp_prot.compat_setsockopt != NULL)
  			return udp_prot.compat_setsockopt(sk, level, optname,
  							  optval, optlen);
  		return udp_prot.setsockopt(sk, level, optname, optval, optlen);
  	}
  
  	if (level != SOL_IPV6)
  		return -ENOPROTOOPT;
  
  	if (optname >= MCAST_JOIN_GROUP && optname <= MCAST_MSFILTER)
  		return compat_mc_setsockopt(sk, level, optname, optval, optlen,
  			ipv6_setsockopt);
  
  	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) {
  		lock_sock(sk);
  		err = compat_nf_setsockopt(sk, PF_INET6, optname,
  					   optval, optlen);
  		release_sock(sk);
  	}
  #endif
  	return err;
  }
  
  EXPORT_SYMBOL(compat_ipv6_setsockopt);
  #endif
  
  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 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:
  	{
  		struct group_filter gsf;
  		int err;
  
  		if (len < GROUP_FILTER_SIZE(0))
  			return -EINVAL;
  		if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0)))
  			return -EFAULT;
  		if (gsf.gf_group.ss_family != AF_INET6)
  			return -EADDRNOTAVAIL;
  		lock_sock(sk);
  		err = ip6_mc_msfget(sk, &gsf,
  			(struct group_filter __user *)optval, optlen);
  		release_sock(sk);
  		return err;
  	}
  
  	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;
  
  		lock_sock(sk);
  		skb = np->pktoptions;
  		if (skb)
  			atomic_inc(&skb->users);
  		release_sock(sk);
  
  		if (skb) {
  			int err = ip6_datagram_recv_ctl(sk, &msg, skb);
  			kfree_skb(skb);
  			if (err)
  				return err;
  		} else {
  			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 ? np->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 = np->rcv_tclass;
  				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 ? np->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);
  			}
  		}
  		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 = np->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:
  	{
  
  		lock_sock(sk);
  		len = ipv6_getsockopt_sticky(sk, np->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;
  		break;
  	}
  
  	case IPV6_TRANSPARENT:
  		val = inet_sk(sk)->transparent;
  		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_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_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;
  
  	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;
  
  		lock_sock(sk);
  		err = nf_getsockopt(sk, PF_INET6, optname, optval,
  				&len);
  		release_sock(sk);
  		if (err >= 0)
  			err = put_user(len, optlen);
  	}
  #endif
  	return err;
  }
  
  EXPORT_SYMBOL(ipv6_getsockopt);
  
  #ifdef CONFIG_COMPAT
  int compat_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) {
  		if (udp_prot.compat_getsockopt != NULL)
  			return udp_prot.compat_getsockopt(sk, level, optname,
  							  optval, optlen);
  		return udp_prot.getsockopt(sk, level, optname, optval, optlen);
  	}
  
  	if (level != SOL_IPV6)
  		return -ENOPROTOOPT;
  
  	if (optname == MCAST_MSFILTER)
  		return compat_mc_getsockopt(sk, level, optname, optval, optlen,
  			ipv6_getsockopt);
  
  	err = do_ipv6_getsockopt(sk, level, optname, optval, optlen,
  				 MSG_CMSG_COMPAT);
  #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;
  
  		lock_sock(sk);
  		err = compat_nf_getsockopt(sk, PF_INET6,
  					   optname, optval, &len);
  		release_sock(sk);
  		if (err >= 0)
  			err = put_user(len, optlen);
  	}
  #endif
  	return err;
  }
  
  EXPORT_SYMBOL(compat_ipv6_getsockopt);
  #endif
  
  