/*
   *	PF_INET6 socket protocol family

   *	Linux INET6 implementation

   *
   *	Authors:

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

   *
   *	Adapted from linux/net/ipv4/af_inet.c
   *

   * 	Fixes:
   *	piggy, Karl Knutson	:	Socket protocol table
   * 	Hideaki YOSHIFUJI	:	sin6_scope_id support
   * 	Arnaldo Melo		: 	check proc_net_create return, cleanups
   *
   *	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.
   */
  
  
  #include <linux/module.h>

  #include <linux/capability.h>

  #include <linux/errno.h>
  #include <linux/types.h>
  #include <linux/socket.h>
  #include <linux/in.h>
  #include <linux/kernel.h>

  #include <linux/timer.h>
  #include <linux/string.h>
  #include <linux/sockios.h>
  #include <linux/net.h>
  #include <linux/fcntl.h>
  #include <linux/mm.h>
  #include <linux/interrupt.h>
  #include <linux/proc_fs.h>
  #include <linux/stat.h>
  #include <linux/init.h>

  #include <linux/slab.h>

  
  #include <linux/inet.h>
  #include <linux/netdevice.h>
  #include <linux/icmpv6.h>

  #include <linux/netfilter_ipv6.h>

  
  #include <net/ip.h>
  #include <net/ipv6.h>
  #include <net/udp.h>

  #include <net/udplite.h>

  #include <net/tcp.h>
  #include <net/ipip.h>
  #include <net/protocol.h>
  #include <net/inet_common.h>

  #include <net/route.h>

  #include <net/transp_v6.h>
  #include <net/ip6_route.h>
  #include <net/addrconf.h>
  #ifdef CONFIG_IPV6_TUNNEL
  #include <net/ip6_tunnel.h>
  #endif
  
  #include <asm/uaccess.h>
  #include <asm/system.h>

  #include <linux/mroute6.h>

  
  MODULE_AUTHOR("Cast of dozens");
  MODULE_DESCRIPTION("IPv6 protocol stack for Linux");
  MODULE_LICENSE("GPL");

  /* The inetsw6 table contains everything that inet6_create needs to

   * build a new socket.
   */
  static struct list_head inetsw6[SOCK_MAX];
  static DEFINE_SPINLOCK(inetsw6_lock);

  struct ipv6_params ipv6_defaults = {
  	.disable_ipv6 = 0,
  	.autoconf = 1,
  };
  
  static int disable_ipv6_mod = 0;
  
  module_param_named(disable, disable_ipv6_mod, int, 0444);
  MODULE_PARM_DESC(disable, "Disable IPv6 module such that it is non-functional");
  
  module_param_named(disable_ipv6, ipv6_defaults.disable_ipv6, int, 0444);
  MODULE_PARM_DESC(disable_ipv6, "Disable IPv6 on all interfaces");
  
  module_param_named(autoconf, ipv6_defaults.autoconf, int, 0444);
  MODULE_PARM_DESC(autoconf, "Enable IPv6 address autoconfiguration on all interfaces");

  static __inline__ struct ipv6_pinfo *inet6_sk_generic(struct sock *sk)
  {
  	const int offset = sk->sk_prot->obj_size - sizeof(struct ipv6_pinfo);
  
  	return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
  }

  static int inet6_create(struct net *net, struct socket *sock, int protocol,
  			int kern)

  {
  	struct inet_sock *inet;
  	struct ipv6_pinfo *np;
  	struct sock *sk;

  	struct inet_protosw *answer;
  	struct proto *answer_prot;
  	unsigned char answer_flags;
  	char answer_no_check;

  	int try_loading_module = 0;
  	int err;

  	if (sock->type != SOCK_RAW &&
  	    sock->type != SOCK_DGRAM &&
  	    !inet_ehash_secret)
  		build_ehash_secret();

  	/* Look for the requested type/protocol pair. */

  lookup_protocol:
  	err = -ESOCKTNOSUPPORT;

  	rcu_read_lock();

  	list_for_each_entry_rcu(answer, &inetsw6[sock->type], list) {

  		err = 0;

  		/* Check the non-wild match. */
  		if (protocol == answer->protocol) {
  			if (protocol != IPPROTO_IP)
  				break;
  		} else {
  			/* Check for the two wild cases. */
  			if (IPPROTO_IP == protocol) {
  				protocol = answer->protocol;
  				break;
  			}
  			if (IPPROTO_IP == answer->protocol)
  				break;
  		}

  		err = -EPROTONOSUPPORT;

  	}

  	if (err) {

  		if (try_loading_module < 2) {
  			rcu_read_unlock();
  			/*
  			 * Be more specific, e.g. net-pf-10-proto-132-type-1
  			 * (net-pf-PF_INET6-proto-IPPROTO_SCTP-type-SOCK_STREAM)
  			 */
  			if (++try_loading_module == 1)
  				request_module("net-pf-%d-proto-%d-type-%d",
  						PF_INET6, protocol, sock->type);
  			/*
  			 * Fall back to generic, e.g. net-pf-10-proto-132
  			 * (net-pf-PF_INET6-proto-IPPROTO_SCTP)
  			 */
  			else
  				request_module("net-pf-%d-proto-%d",
  						PF_INET6, protocol);
  			goto lookup_protocol;
  		} else
  			goto out_rcu_unlock;
  	}
  
  	err = -EPERM;

  	if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))

  		goto out_rcu_unlock;

  
  	sock->ops = answer->ops;

  	answer_prot = answer->prot;
  	answer_no_check = answer->no_check;
  	answer_flags = answer->flags;
  	rcu_read_unlock();

  	WARN_ON(answer_prot->slab == NULL);

  	err = -ENOBUFS;

  	sk = sk_alloc(net, PF_INET6, GFP_KERNEL, answer_prot);

  	if (sk == NULL)
  		goto out;
  
  	sock_init_data(sock, sk);

  	err = 0;

  	sk->sk_no_check = answer_no_check;
  	if (INET_PROTOSW_REUSE & answer_flags)
  		sk->sk_reuse = 1;
  
  	inet = inet_sk(sk);

  	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;

  
  	if (SOCK_RAW == sock->type) {

  		inet->inet_num = protocol;

  		if (IPPROTO_RAW == protocol)
  			inet->hdrincl = 1;
  	}

  	sk->sk_destruct		= inet_sock_destruct;

  	sk->sk_family		= PF_INET6;
  	sk->sk_protocol		= protocol;
  
  	sk->sk_backlog_rcv	= answer->prot->backlog_rcv;
  
  	inet_sk(sk)->pinet6 = np = inet6_sk_generic(sk);
  	np->hop_limit	= -1;

  	np->mcast_hops	= IPV6_DEFAULT_MCASTHOPS;

  	np->mc_loop	= 1;
  	np->pmtudisc	= IPV6_PMTUDISC_WANT;

  	np->ipv6only	= net->ipv6.sysctl.bindv6only;

  	/* Init the ipv4 part of the socket since we can have sockets
  	 * using v6 API for ipv4.
  	 */
  	inet->uc_ttl	= -1;
  
  	inet->mc_loop	= 1;
  	inet->mc_ttl	= 1;
  	inet->mc_index	= 0;
  	inet->mc_list	= NULL;
  
  	if (ipv4_config.no_pmtu_disc)
  		inet->pmtudisc = IP_PMTUDISC_DONT;
  	else
  		inet->pmtudisc = IP_PMTUDISC_WANT;

  	/*

  	 * Increment only the relevant sk_prot->socks debug field, this changes
  	 * the previous behaviour of incrementing both the equivalent to
  	 * answer->prot->socks (inet6_sock_nr) and inet_sock_nr.
  	 *
  	 * This allows better debug granularity as we'll know exactly how many
  	 * UDPv6, TCPv6, etc socks were allocated, not the sum of all IPv6
  	 * transport protocol socks. -acme
  	 */
  	sk_refcnt_debug_inc(sk);

  	if (inet->inet_num) {

  		/* It assumes that any protocol which allows
  		 * the user to assign a number at socket
  		 * creation time automatically shares.
  		 */

  		inet->inet_sport = htons(inet->inet_num);

  		sk->sk_prot->hash(sk);
  	}
  	if (sk->sk_prot->init) {

  		err = sk->sk_prot->init(sk);
  		if (err) {

  			sk_common_release(sk);
  			goto out;
  		}
  	}
  out:

  	return err;

  out_rcu_unlock:
  	rcu_read_unlock();
  	goto out;
  }
  
  
  /* bind for INET6 API */
  int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
  {
  	struct sockaddr_in6 *addr=(struct sockaddr_in6 *)uaddr;
  	struct sock *sk = sock->sk;
  	struct inet_sock *inet = inet_sk(sk);
  	struct ipv6_pinfo *np = inet6_sk(sk);

  	struct net *net = sock_net(sk);

  	__be32 v4addr = 0;

  	unsigned short snum;
  	int addr_type = 0;
  	int err = 0;
  
  	/* If the socket has its own bind function then use it. */
  	if (sk->sk_prot->bind)
  		return sk->sk_prot->bind(sk, uaddr, addr_len);
  
  	if (addr_len < SIN6_LEN_RFC2133)
  		return -EINVAL;

  
  	if (addr->sin6_family != AF_INET6)

  		return -EAFNOSUPPORT;

  	addr_type = ipv6_addr_type(&addr->sin6_addr);
  	if ((addr_type & IPV6_ADDR_MULTICAST) && sock->type == SOCK_STREAM)
  		return -EINVAL;
  
  	snum = ntohs(addr->sin6_port);
  	if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
  		return -EACCES;
  
  	lock_sock(sk);
  
  	/* Check these errors (active socket, double bind). */

  	if (sk->sk_state != TCP_CLOSE || inet->inet_num) {

  		err = -EINVAL;
  		goto out;
  	}
  
  	/* Check if the address belongs to the host. */
  	if (addr_type == IPV6_ADDR_MAPPED) {

  		int chk_addr_ret;

  		/* Binding to v4-mapped address on a v6-only socket
  		 * makes no sense
  		 */
  		if (np->ipv6only) {
  			err = -EINVAL;
  			goto out;
  		}

  		/* Reproduce AF_INET checks to make the bindings consistent */

  		v4addr = addr->sin6_addr.s6_addr32[3];

  		chk_addr_ret = inet_addr_type(net, v4addr);
  		if (!sysctl_ip_nonlocal_bind &&
  		    !(inet->freebind || inet->transparent) &&
  		    v4addr != htonl(INADDR_ANY) &&
  		    chk_addr_ret != RTN_LOCAL &&
  		    chk_addr_ret != RTN_MULTICAST &&

  		    chk_addr_ret != RTN_BROADCAST) {
  			err = -EADDRNOTAVAIL;

  			goto out;

  		}

  	} else {
  		if (addr_type != IPV6_ADDR_ANY) {
  			struct net_device *dev = NULL;

  			rcu_read_lock();

  			if (addr_type & IPV6_ADDR_LINKLOCAL) {
  				if (addr_len >= sizeof(struct sockaddr_in6) &&
  				    addr->sin6_scope_id) {
  					/* Override any existing binding, if another one
  					 * is supplied by user.
  					 */
  					sk->sk_bound_dev_if = addr->sin6_scope_id;
  				}

  				/* Binding to link-local address requires an interface */
  				if (!sk->sk_bound_dev_if) {
  					err = -EINVAL;

  					goto out_unlock;

  				}

  				dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);

  				if (!dev) {
  					err = -ENODEV;

  					goto out_unlock;

  				}
  			}
  
  			/* ipv4 addr of the socket is invalid.  Only the
  			 * unspecified and mapped address have a v4 equivalent.
  			 */
  			v4addr = LOOPBACK4_IPV6;
  			if (!(addr_type & IPV6_ADDR_MULTICAST))	{

  				if (!(inet->freebind || inet->transparent) &&

  				    !ipv6_chk_addr(net, &addr->sin6_addr,

  						   dev, 0)) {

  					err = -EADDRNOTAVAIL;

  					goto out_unlock;

  				}
  			}

  			rcu_read_unlock();

  		}
  	}

  	inet->inet_rcv_saddr = v4addr;
  	inet->inet_saddr = v4addr;

  	np->rcv_saddr = addr->sin6_addr;

  	if (!(addr_type & IPV6_ADDR_MULTICAST))

  		np->saddr = addr->sin6_addr;

  
  	/* Make sure we are allowed to bind here. */
  	if (sk->sk_prot->get_port(sk, snum)) {
  		inet_reset_saddr(sk);
  		err = -EADDRINUSE;
  		goto out;
  	}

  	if (addr_type != IPV6_ADDR_ANY) {

  		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;

  		if (addr_type != IPV6_ADDR_MAPPED)
  			np->ipv6only = 1;
  	}

  	if (snum)
  		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;

  	inet->inet_sport = htons(inet->inet_num);
  	inet->inet_dport = 0;
  	inet->inet_daddr = 0;

  out:
  	release_sock(sk);
  	return err;

  out_unlock:
  	rcu_read_unlock();
  	goto out;

  }

  EXPORT_SYMBOL(inet6_bind);

  int inet6_release(struct socket *sock)
  {
  	struct sock *sk = sock->sk;
  
  	if (sk == NULL)
  		return -EINVAL;
  
  	/* Free mc lists */
  	ipv6_sock_mc_close(sk);
  
  	/* Free ac lists */
  	ipv6_sock_ac_close(sk);
  
  	return inet_release(sock);
  }

  EXPORT_SYMBOL(inet6_release);

  void inet6_destroy_sock(struct sock *sk)

  {
  	struct ipv6_pinfo *np = inet6_sk(sk);
  	struct sk_buff *skb;
  	struct ipv6_txoptions *opt;

  	/* Release rx options */
  
  	if ((skb = xchg(&np->pktoptions, NULL)) != NULL)
  		kfree_skb(skb);

  
  	if ((skb = xchg(&np->rxpmtu, NULL)) != NULL)
  		kfree_skb(skb);

  
  	/* Free flowlabels */
  	fl6_free_socklist(sk);
  
  	/* Free tx options */
  
  	if ((opt = xchg(&np->opt, NULL)) != NULL)
  		sock_kfree_s(sk, opt, opt->tot_len);

  }

  EXPORT_SYMBOL_GPL(inet6_destroy_sock);

  /*
   *	This does both peername and sockname.
   */

  int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
  		 int *uaddr_len, int peer)
  {
  	struct sockaddr_in6 *sin=(struct sockaddr_in6 *)uaddr;
  	struct sock *sk = sock->sk;
  	struct inet_sock *inet = inet_sk(sk);
  	struct ipv6_pinfo *np = inet6_sk(sk);

  	sin->sin6_family = AF_INET6;
  	sin->sin6_flowinfo = 0;
  	sin->sin6_scope_id = 0;
  	if (peer) {

  		if (!inet->inet_dport)

  			return -ENOTCONN;
  		if (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
  		    peer == 1)
  			return -ENOTCONN;

  		sin->sin6_port = inet->inet_dport;

  		sin->sin6_addr = np->daddr;

  		if (np->sndflow)
  			sin->sin6_flowinfo = np->flow_label;
  	} else {
  		if (ipv6_addr_any(&np->rcv_saddr))

  			sin->sin6_addr = np->saddr;

  		else

  			sin->sin6_addr = np->rcv_saddr;

  		sin->sin6_port = inet->inet_sport;

  	}
  	if (ipv6_addr_type(&sin->sin6_addr) & IPV6_ADDR_LINKLOCAL)
  		sin->sin6_scope_id = sk->sk_bound_dev_if;
  	*uaddr_len = sizeof(*sin);

  	return 0;

  }

  EXPORT_SYMBOL(inet6_getname);

  int inet6_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
  {
  	struct sock *sk = sock->sk;

  	struct net *net = sock_net(sk);

  	switch(cmd)

  	{
  	case SIOCGSTAMP:
  		return sock_get_timestamp(sk, (struct timeval __user *)arg);

  	case SIOCGSTAMPNS:
  		return sock_get_timestampns(sk, (struct timespec __user *)arg);

  	case SIOCADDRT:
  	case SIOCDELRT:

  		return ipv6_route_ioctl(net, cmd, (void __user *)arg);

  
  	case SIOCSIFADDR:

  		return addrconf_add_ifaddr(net, (void __user *) arg);

  	case SIOCDIFADDR:

  		return addrconf_del_ifaddr(net, (void __user *) arg);

  	case SIOCSIFDSTADDR:

  		return addrconf_set_dstaddr(net, (void __user *) arg);

  	default:

  		if (!sk->sk_prot->ioctl)
  			return -ENOIOCTLCMD;
  		return sk->sk_prot->ioctl(sk, cmd, arg);

  	}
  	/*NOTREACHED*/

  	return 0;

  }

  EXPORT_SYMBOL(inet6_ioctl);

  const struct proto_ops inet6_stream_ops = {

  	.family		   = PF_INET6,
  	.owner		   = THIS_MODULE,
  	.release	   = inet6_release,
  	.bind		   = inet6_bind,
  	.connect	   = inet_stream_connect,	/* ok		*/
  	.socketpair	   = sock_no_socketpair,	/* a do nothing	*/
  	.accept		   = inet_accept,		/* ok		*/
  	.getname	   = inet6_getname,
  	.poll		   = tcp_poll,			/* ok		*/
  	.ioctl		   = inet6_ioctl,		/* must change  */
  	.listen		   = inet_listen,		/* ok		*/
  	.shutdown	   = inet_shutdown,		/* ok		*/
  	.setsockopt	   = sock_common_setsockopt,	/* ok		*/
  	.getsockopt	   = sock_common_getsockopt,	/* ok		*/

  	.sendmsg	   = inet_sendmsg,		/* ok		*/
  	.recvmsg	   = inet_recvmsg,		/* ok		*/

  	.mmap		   = sock_no_mmap,

  	.sendpage	   = inet_sendpage,

  	.splice_read	   = tcp_splice_read,

  #ifdef CONFIG_COMPAT

  	.compat_setsockopt = compat_sock_common_setsockopt,
  	.compat_getsockopt = compat_sock_common_getsockopt,

  #endif

  };

  const struct proto_ops inet6_dgram_ops = {

  	.family		   = PF_INET6,
  	.owner		   = THIS_MODULE,
  	.release	   = inet6_release,
  	.bind		   = inet6_bind,
  	.connect	   = inet_dgram_connect,	/* ok		*/
  	.socketpair	   = sock_no_socketpair,	/* a do nothing	*/
  	.accept		   = sock_no_accept,		/* a do nothing	*/
  	.getname	   = inet6_getname,
  	.poll		   = udp_poll,			/* ok		*/
  	.ioctl		   = inet6_ioctl,		/* must change  */
  	.listen		   = sock_no_listen,		/* ok		*/
  	.shutdown	   = inet_shutdown,		/* ok		*/
  	.setsockopt	   = sock_common_setsockopt,	/* ok		*/
  	.getsockopt	   = sock_common_getsockopt,	/* ok		*/
  	.sendmsg	   = inet_sendmsg,		/* ok		*/

  	.recvmsg	   = inet_recvmsg,		/* ok		*/

  	.mmap		   = sock_no_mmap,
  	.sendpage	   = sock_no_sendpage,

  #ifdef CONFIG_COMPAT

  	.compat_setsockopt = compat_sock_common_setsockopt,
  	.compat_getsockopt = compat_sock_common_getsockopt,

  #endif

  };

  static const struct net_proto_family inet6_family_ops = {

  	.family = PF_INET6,
  	.create = inet6_create,
  	.owner	= THIS_MODULE,
  };

  int inet6_register_protosw(struct inet_protosw *p)

  {
  	struct list_head *lh;
  	struct inet_protosw *answer;

  	struct list_head *last_perm;

  	int protocol = p->protocol;
  	int ret;

  
  	spin_lock_bh(&inetsw6_lock);

  	ret = -EINVAL;

  	if (p->type >= SOCK_MAX)
  		goto out_illegal;
  
  	/* If we are trying to override a permanent protocol, bail. */
  	answer = NULL;

  	ret = -EPERM;

  	last_perm = &inetsw6[p->type];
  	list_for_each(lh, &inetsw6[p->type]) {
  		answer = list_entry(lh, struct inet_protosw, list);
  
  		/* Check only the non-wild match. */
  		if (INET_PROTOSW_PERMANENT & answer->flags) {
  			if (protocol == answer->protocol)
  				break;
  			last_perm = lh;
  		}
  
  		answer = NULL;
  	}
  	if (answer)
  		goto out_permanent;
  
  	/* Add the new entry after the last permanent entry if any, so that
  	 * the new entry does not override a permanent entry when matched with
  	 * a wild-card protocol. But it is allowed to override any existing

  	 * non-permanent entry.  This means that when we remove this entry, the

  	 * system automatically returns to the old behavior.
  	 */
  	list_add_rcu(&p->list, last_perm);

  	ret = 0;

  out:
  	spin_unlock_bh(&inetsw6_lock);

  	return ret;

  
  out_permanent:
  	printk(KERN_ERR "Attempt to override permanent protocol %d.
  ",
  	       protocol);
  	goto out;
  
  out_illegal:
  	printk(KERN_ERR
  	       "Ignoring attempt to register invalid socket type %d.
  ",
  	       p->type);
  	goto out;
  }

  EXPORT_SYMBOL(inet6_register_protosw);

  void
  inet6_unregister_protosw(struct inet_protosw *p)
  {
  	if (INET_PROTOSW_PERMANENT & p->flags) {
  		printk(KERN_ERR
  		       "Attempt to unregister permanent protocol %d.
  ",
  		       p->protocol);
  	} else {
  		spin_lock_bh(&inetsw6_lock);
  		list_del_rcu(&p->list);
  		spin_unlock_bh(&inetsw6_lock);
  
  		synchronize_net();
  	}
  }

  EXPORT_SYMBOL(inet6_unregister_protosw);

  int inet6_sk_rebuild_header(struct sock *sk)
  {

  	struct ipv6_pinfo *np = inet6_sk(sk);

  	struct dst_entry *dst;

  
  	dst = __sk_dst_check(sk, np->dst_cookie);
  
  	if (dst == NULL) {
  		struct inet_sock *inet = inet_sk(sk);

  		struct in6_addr *final_p, final;

  		struct flowi6 fl6;
  
  		memset(&fl6, 0, sizeof(fl6));
  		fl6.flowi6_proto = sk->sk_protocol;

  		fl6.daddr = np->daddr;
  		fl6.saddr = np->saddr;

  		fl6.flowlabel = np->flow_label;
  		fl6.flowi6_oif = sk->sk_bound_dev_if;
  		fl6.flowi6_mark = sk->sk_mark;

  		fl6.fl6_dport = inet->inet_dport;
  		fl6.fl6_sport = inet->inet_sport;

  		security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
  
  		final_p = fl6_update_dst(&fl6, np->opt, &final);
  
  		dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false);

  		if (IS_ERR(dst)) {

  			sk->sk_route_caps = 0;

  			sk->sk_err_soft = -PTR_ERR(dst);
  			return PTR_ERR(dst);

  		}

  		__ip6_dst_store(sk, dst, NULL, NULL);

  	}
  
  	return 0;
  }
  
  EXPORT_SYMBOL_GPL(inet6_sk_rebuild_header);

  int ipv6_opt_accepted(struct sock *sk, struct sk_buff *skb)
  {
  	struct ipv6_pinfo *np = inet6_sk(sk);
  	struct inet6_skb_parm *opt = IP6CB(skb);
  
  	if (np->rxopt.all) {
  		if ((opt->hop && (np->rxopt.bits.hopopts ||
  				  np->rxopt.bits.ohopopts)) ||

  		    ((IPV6_FLOWINFO_MASK &
  		      *(__be32 *)skb_network_header(skb)) &&

  		     np->rxopt.bits.rxflow) ||
  		    (opt->srcrt && (np->rxopt.bits.srcrt ||
  		     np->rxopt.bits.osrcrt)) ||
  		    ((opt->dst1 || opt->dst0) &&
  		     (np->rxopt.bits.dstopts || np->rxopt.bits.odstopts)))
  			return 1;
  	}
  	return 0;
  }
  
  EXPORT_SYMBOL_GPL(ipv6_opt_accepted);

  static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto)

  {

  	const struct inet6_protocol *ops = NULL;

  
  	for (;;) {
  		struct ipv6_opt_hdr *opth;
  		int len;
  
  		if (proto != NEXTHDR_HOP) {
  			ops = rcu_dereference(inet6_protos[proto]);
  
  			if (unlikely(!ops))
  				break;
  
  			if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
  				break;
  		}
  
  		if (unlikely(!pskb_may_pull(skb, 8)))
  			break;
  
  		opth = (void *)skb->data;
  		len = ipv6_optlen(opth);
  
  		if (unlikely(!pskb_may_pull(skb, len)))
  			break;
  
  		proto = opth->nexthdr;
  		__skb_pull(skb, len);
  	}

  	return proto;

  }
  
  static int ipv6_gso_send_check(struct sk_buff *skb)
  {

  	const struct ipv6hdr *ipv6h;

  	const struct inet6_protocol *ops;

  	int err = -EINVAL;
  
  	if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
  		goto out;
  
  	ipv6h = ipv6_hdr(skb);
  	__skb_pull(skb, sizeof(*ipv6h));
  	err = -EPROTONOSUPPORT;
  
  	rcu_read_lock();

  	ops = rcu_dereference(inet6_protos[
  		ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr)]);

  	if (likely(ops && ops->gso_send_check)) {
  		skb_reset_transport_header(skb);
  		err = ops->gso_send_check(skb);
  	}
  	rcu_read_unlock();
  
  out:
  	return err;
  }

  static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
  	netdev_features_t features)

  {
  	struct sk_buff *segs = ERR_PTR(-EINVAL);
  	struct ipv6hdr *ipv6h;

  	const struct inet6_protocol *ops;

  	int proto;
  	struct frag_hdr *fptr;
  	unsigned int unfrag_ip6hlen;
  	u8 *prevhdr;
  	int offset = 0;

  
  	if (!(features & NETIF_F_V6_CSUM))
  		features &= ~NETIF_F_SG;
  
  	if (unlikely(skb_shinfo(skb)->gso_type &
  		     ~(SKB_GSO_UDP |
  		       SKB_GSO_DODGY |
  		       SKB_GSO_TCP_ECN |
  		       SKB_GSO_TCPV6 |
  		       0)))
  		goto out;
  
  	if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
  		goto out;
  
  	ipv6h = ipv6_hdr(skb);
  	__skb_pull(skb, sizeof(*ipv6h));
  	segs = ERR_PTR(-EPROTONOSUPPORT);

  	proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr);

  	rcu_read_lock();

  	ops = rcu_dereference(inet6_protos[proto]);

  	if (likely(ops && ops->gso_segment)) {
  		skb_reset_transport_header(skb);
  		segs = ops->gso_segment(skb, features);
  	}
  	rcu_read_unlock();

  	if (IS_ERR(segs))

  		goto out;
  
  	for (skb = segs; skb; skb = skb->next) {
  		ipv6h = ipv6_hdr(skb);
  		ipv6h->payload_len = htons(skb->len - skb->mac_len -
  					   sizeof(*ipv6h));

  		if (proto == IPPROTO_UDP) {
  			unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
  			fptr = (struct frag_hdr *)(skb_network_header(skb) +
  				unfrag_ip6hlen);
  			fptr->frag_off = htons(offset);
  			if (skb->next != NULL)
  				fptr->frag_off |= htons(IP6_MF);
  			offset += (ntohs(ipv6h->payload_len) -
  				   sizeof(struct frag_hdr));
  		}

  	}
  
  out:
  	return segs;
  }

  struct ipv6_gro_cb {
  	struct napi_gro_cb napi;
  	int proto;
  };
  
  #define IPV6_GRO_CB(skb) ((struct ipv6_gro_cb *)(skb)->cb)
  
  static struct sk_buff **ipv6_gro_receive(struct sk_buff **head,
  					 struct sk_buff *skb)
  {

  	const struct inet6_protocol *ops;

  	struct sk_buff **pp = NULL;
  	struct sk_buff *p;
  	struct ipv6hdr *iph;
  	unsigned int nlen;

  	unsigned int hlen;
  	unsigned int off;

  	int flush = 1;
  	int proto;

  	__wsum csum;

  	off = skb_gro_offset(skb);
  	hlen = off + sizeof(*iph);
  	iph = skb_gro_header_fast(skb, off);
  	if (skb_gro_header_hard(skb, hlen)) {
  		iph = skb_gro_header_slow(skb, hlen, off);
  		if (unlikely(!iph))
  			goto out;
  	}

  	skb_gro_pull(skb, sizeof(*iph));
  	skb_set_transport_header(skb, skb_gro_offset(skb));

  	flush += ntohs(iph->payload_len) != skb_gro_len(skb);

  
  	rcu_read_lock();

  	proto = iph->nexthdr;

  	ops = rcu_dereference(inet6_protos[proto]);

  	if (!ops || !ops->gro_receive) {
  		__pskb_pull(skb, skb_gro_offset(skb));
  		proto = ipv6_gso_pull_exthdrs(skb, proto);
  		skb_gro_pull(skb, -skb_transport_offset(skb));
  		skb_reset_transport_header(skb);
  		__skb_push(skb, skb_gro_offset(skb));

  		ops = rcu_dereference(inet6_protos[proto]);

  		if (!ops || !ops->gro_receive)
  			goto out_unlock;
  
  		iph = ipv6_hdr(skb);
  	}
  
  	IPV6_GRO_CB(skb)->proto = proto;

  
  	flush--;

  	nlen = skb_network_header_len(skb);
  
  	for (p = *head; p; p = p->next) {
  		struct ipv6hdr *iph2;
  
  		if (!NAPI_GRO_CB(p)->same_flow)
  			continue;
  
  		iph2 = ipv6_hdr(p);
  
  		/* All fields must match except length. */
  		if (nlen != skb_network_header_len(p) ||
  		    memcmp(iph, iph2, offsetof(struct ipv6hdr, payload_len)) ||
  		    memcmp(&iph->nexthdr, &iph2->nexthdr,
  			   nlen - offsetof(struct ipv6hdr, nexthdr))) {
  			NAPI_GRO_CB(p)->same_flow = 0;
  			continue;
  		}
  
  		NAPI_GRO_CB(p)->flush |= flush;
  	}
  
  	NAPI_GRO_CB(skb)->flush |= flush;

  	csum = skb->csum;
  	skb_postpull_rcsum(skb, iph, skb_network_header_len(skb));

  	pp = ops->gro_receive(head, skb);

  	skb->csum = csum;

  out_unlock:
  	rcu_read_unlock();
  
  out:
  	NAPI_GRO_CB(skb)->flush |= flush;
  
  	return pp;
  }
  
  static int ipv6_gro_complete(struct sk_buff *skb)
  {

  	const struct inet6_protocol *ops;

  	struct ipv6hdr *iph = ipv6_hdr(skb);
  	int err = -ENOSYS;
  
  	iph->payload_len = htons(skb->len - skb_network_offset(skb) -
  				 sizeof(*iph));
  
  	rcu_read_lock();
  	ops = rcu_dereference(inet6_protos[IPV6_GRO_CB(skb)->proto]);
  	if (WARN_ON(!ops || !ops->gro_complete))
  		goto out_unlock;
  
  	err = ops->gro_complete(skb);
  
  out_unlock:
  	rcu_read_unlock();
  
  	return err;
  }

  static struct packet_type ipv6_packet_type __read_mostly = {

  	.type = cpu_to_be16(ETH_P_IPV6),

  	.func = ipv6_rcv,
  	.gso_send_check = ipv6_gso_send_check,
  	.gso_segment = ipv6_gso_segment,

  	.gro_receive = ipv6_gro_receive,
  	.gro_complete = ipv6_gro_complete,

  };
  
  static int __init ipv6_packet_init(void)
  {
  	dev_add_pack(&ipv6_packet_type);
  	return 0;
  }
  
  static void ipv6_packet_cleanup(void)
  {
  	dev_remove_pack(&ipv6_packet_type);
  }

  static int __net_init ipv6_init_mibs(struct net *net)
  {

  	if (snmp_mib_init((void __percpu **)net->mib.udp_stats_in6,

  			  sizeof(struct udp_mib),
  			  __alignof__(struct udp_mib)) < 0)

  		return -ENOMEM;

  	if (snmp_mib_init((void __percpu **)net->mib.udplite_stats_in6,

  			  sizeof(struct udp_mib),
  			  __alignof__(struct udp_mib)) < 0)

  		goto err_udplite_mib;

  	if (snmp_mib_init((void __percpu **)net->mib.ipv6_statistics,

  			  sizeof(struct ipstats_mib),
  			  __alignof__(struct ipstats_mib)) < 0)

  		goto err_ip_mib;

  	if (snmp_mib_init((void __percpu **)net->mib.icmpv6_statistics,

  			  sizeof(struct icmpv6_mib),
  			  __alignof__(struct icmpv6_mib)) < 0)

  		goto err_icmp_mib;

  	net->mib.icmpv6msg_statistics = kzalloc(sizeof(struct icmpv6msg_mib),
  						GFP_KERNEL);
  	if (!net->mib.icmpv6msg_statistics)

  		goto err_icmpmsg_mib;

  	return 0;

  err_icmpmsg_mib:

  	snmp_mib_free((void __percpu **)net->mib.icmpv6_statistics);

  err_icmp_mib:

  	snmp_mib_free((void __percpu **)net->mib.ipv6_statistics);

  err_ip_mib:

  	snmp_mib_free((void __percpu **)net->mib.udplite_stats_in6);

  err_udplite_mib:

  	snmp_mib_free((void __percpu **)net->mib.udp_stats_in6);

  	return -ENOMEM;

  }

  static void ipv6_cleanup_mibs(struct net *net)

  {

  	snmp_mib_free((void __percpu **)net->mib.udp_stats_in6);
  	snmp_mib_free((void __percpu **)net->mib.udplite_stats_in6);
  	snmp_mib_free((void __percpu **)net->mib.ipv6_statistics);
  	snmp_mib_free((void __percpu **)net->mib.icmpv6_statistics);

  	kfree(net->mib.icmpv6msg_statistics);

  }

  static int __net_init inet6_net_init(struct net *net)

  {

  	int err = 0;

  	net->ipv6.sysctl.bindv6only = 0;

  	net->ipv6.sysctl.icmpv6_time = 1*HZ;

  	err = ipv6_init_mibs(net);
  	if (err)
  		return err;

  #ifdef CONFIG_PROC_FS
  	err = udp6_proc_init(net);
  	if (err)
  		goto out;

  	err = tcp6_proc_init(net);
  	if (err)
  		goto proc_tcp6_fail;

  	err = ac6_proc_init(net);
  	if (err)
  		goto proc_ac6_fail;

  #endif
  	return err;

  
  #ifdef CONFIG_PROC_FS

  proc_ac6_fail:
  	tcp6_proc_exit(net);

  proc_tcp6_fail:
  	udp6_proc_exit(net);

  out:
  	ipv6_cleanup_mibs(net);
  	return err;

  #endif

  }

  static void __net_exit inet6_net_exit(struct net *net)

  {

  #ifdef CONFIG_PROC_FS
  	udp6_proc_exit(net);

  	tcp6_proc_exit(net);

  	ac6_proc_exit(net);

  #endif

  	ipv6_cleanup_mibs(net);

  }
  
  static struct pernet_operations inet6_net_ops = {
  	.init = inet6_net_init,
  	.exit = inet6_net_exit,
  };

  static int __init inet6_init(void)
  {
  	struct sk_buff *dummy_skb;

  	struct list_head *r;

  	int err = 0;

  	BUILD_BUG_ON(sizeof(struct inet6_skb_parm) > sizeof(dummy_skb->cb));

  	/* Register the socket-side information for inet6_create.  */
  	for(r = &inetsw6[0]; r < &inetsw6[SOCK_MAX]; ++r)
  		INIT_LIST_HEAD(r);

  	if (disable_ipv6_mod) {

  		printk(KERN_INFO
  		       "IPv6: Loaded, but administratively disabled, "
  		       "reboot required to enable
  ");
  		goto out;
  	}

  	err = proto_register(&tcpv6_prot, 1);
  	if (err)
  		goto out;
  
  	err = proto_register(&udpv6_prot, 1);
  	if (err)
  		goto out_unregister_tcp_proto;

  	err = proto_register(&udplitev6_prot, 1);

  	if (err)
  		goto out_unregister_udp_proto;

  	err = proto_register(&rawv6_prot, 1);
  	if (err)
  		goto out_unregister_udplite_proto;

  	/* We MUST register RAW sockets before we create the ICMP6,
  	 * IGMP6, or NDISC control sockets.
  	 */

  	err = rawv6_init();
  	if (err)
  		goto out_unregister_raw_proto;

  
  	/* Register the family here so that the init calls below will
  	 * be able to create sockets. (?? is this dangerous ??)
  	 */

  	err = sock_register(&inet6_family_ops);
  	if (err)

  		goto out_sock_register_fail;

  #ifdef CONFIG_SYSCTL
  	err = ipv6_static_sysctl_register();
  	if (err)
  		goto static_sysctl_fail;
  #endif

  	tcpv6_prot.sysctl_mem = init_net.ipv4.sysctl_tcp_mem;

  	/*
  	 *	ipngwg API draft makes clear that the correct semantics
  	 *	for TCP and UDP is to consider one TCP and UDP instance

  	 *	in a host available by both INET and INET6 APIs and

  	 *	able to communicate via both network protocols.
  	 */

  	err = register_pernet_subsys(&inet6_net_ops);
  	if (err)
  		goto register_pernet_fail;

  	err = icmpv6_init();

  	if (err)
  		goto icmp_fail;

  	err = ip6_mr_init();
  	if (err)
  		goto ipmr_fail;

  	err = ndisc_init();

  	if (err)
  		goto ndisc_fail;

  	err = igmp6_init();

  	if (err)
  		goto igmp_fail;

  	err = ipv6_netfilter_init();
  	if (err)
  		goto netfilter_fail;

  	/* Create /proc/foo6 entries. */
  #ifdef CONFIG_PROC_FS
  	err = -ENOMEM;
  	if (raw6_proc_init())
  		goto proc_raw6_fail;

  	if (udplite6_proc_init())
  		goto proc_udplite6_fail;

  	if (ipv6_misc_proc_init())
  		goto proc_misc6_fail;

  	if (if6_proc_init())
  		goto proc_if6_fail;
  #endif

  	err = ip6_route_init();
  	if (err)
  		goto ip6_route_fail;

  	err = ip6_flowlabel_init();
  	if (err)
  		goto ip6_flowlabel_fail;

  	err = addrconf_init();
  	if (err)
  		goto addrconf_fail;

  
  	/* Init v6 extension headers. */

  	err = ipv6_exthdrs_init();
  	if (err)
  		goto ipv6_exthdrs_fail;

  	err = ipv6_frag_init();
  	if (err)
  		goto ipv6_frag_fail;

  
  	/* Init v6 transport protocols. */

  	err = udpv6_init();
  	if (err)
  		goto udpv6_fail;

  	err = udplitev6_init();
  	if (err)
  		goto udplitev6_fail;
  
  	err = tcpv6_init();
  	if (err)
  		goto tcpv6_fail;
  
  	err = ipv6_packet_init();
  	if (err)
  		goto ipv6_packet_fail;

  
  #ifdef CONFIG_SYSCTL
  	err = ipv6_sysctl_register();
  	if (err)
  		goto sysctl_fail;
  #endif

  out:
  	return err;

  #ifdef CONFIG_SYSCTL
  sysctl_fail:
  	ipv6_packet_cleanup();
  #endif

  ipv6_packet_fail:
  	tcpv6_exit();
  tcpv6_fail:
  	udplitev6_exit();
  udplitev6_fail:
  	udpv6_exit();
  udpv6_fail:
  	ipv6_frag_exit();

  ipv6_frag_fail:
  	ipv6_exthdrs_exit();

  ipv6_exthdrs_fail:
  	addrconf_cleanup();

  addrconf_fail:
  	ip6_flowlabel_cleanup();

  ip6_flowlabel_fail:

  	ip6_route_cleanup();

  ip6_route_fail:

  #ifdef CONFIG_PROC_FS
  	if6_proc_exit();
  proc_if6_fail:

  	ipv6_misc_proc_exit();
  proc_misc6_fail:

  	udplite6_proc_exit();
  proc_udplite6_fail:

  	raw6_proc_exit();
  proc_raw6_fail:
  #endif

  	ipv6_netfilter_fini();
  netfilter_fail:

  	igmp6_cleanup();
  igmp_fail:
  	ndisc_cleanup();
  ndisc_fail:

  	ip6_mr_cleanup();
  ipmr_fail:

  	icmpv6_cleanup();
  icmp_fail:

  	unregister_pernet_subsys(&inet6_net_ops);
  register_pernet_fail:

  #ifdef CONFIG_SYSCTL
  	ipv6_static_sysctl_unregister();
  static_sysctl_fail:
  #endif

  	sock_unregister(PF_INET6);

  	rtnl_unregister_all(PF_INET6);

  out_sock_register_fail:
  	rawv6_exit();

  out_unregister_raw_proto:
  	proto_unregister(&rawv6_prot);

  out_unregister_udplite_proto:
  	proto_unregister(&udplitev6_prot);

  out_unregister_udp_proto:
  	proto_unregister(&udpv6_prot);
  out_unregister_tcp_proto:
  	proto_unregister(&tcpv6_prot);
  	goto out;
  }
  module_init(inet6_init);
  
  static void __exit inet6_exit(void)
  {

  	if (disable_ipv6_mod)

  		return;

  	/* First of all disallow new sockets creation. */
  	sock_unregister(PF_INET6);

  	/* Disallow any further netlink messages */
  	rtnl_unregister_all(PF_INET6);

  #ifdef CONFIG_SYSCTL
  	ipv6_sysctl_unregister();
  #endif

  	udpv6_exit();
  	udplitev6_exit();
  	tcpv6_exit();

  	/* Cleanup code parts. */
  	ipv6_packet_cleanup();

  	ipv6_frag_exit();

  	ipv6_exthdrs_exit();

  	addrconf_cleanup();
  	ip6_flowlabel_cleanup();
  	ip6_route_cleanup();

  #ifdef CONFIG_PROC_FS

  
  	/* Cleanup code parts. */

  	if6_proc_exit();

  	ipv6_misc_proc_exit();

  	udplite6_proc_exit();

  	raw6_proc_exit();

  #endif

  	ipv6_netfilter_fini();

  	igmp6_cleanup();

  	ndisc_cleanup();

  	ip6_mr_cleanup();

  	icmpv6_cleanup();

  	rawv6_exit();

  	unregister_pernet_subsys(&inet6_net_ops);

  #ifdef CONFIG_SYSCTL
  	ipv6_static_sysctl_unregister();
  #endif

  	proto_unregister(&rawv6_prot);

  	proto_unregister(&udplitev6_prot);

  	proto_unregister(&udpv6_prot);
  	proto_unregister(&tcpv6_prot);

  
  	rcu_barrier(); /* Wait for completion of call_rcu()'s */

  }
  module_exit(inet6_exit);
  
  MODULE_ALIAS_NETPROTO(PF_INET6);