/*
   *	RAW sockets for IPv6

   *	Linux INET6 implementation

   *
   *	Authors:

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

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

   *	Fixes:
   *	Hideaki YOSHIFUJI	:	sin6_scope_id support

   *	YOSHIFUJI,H.@USAGI	:	raw checksum (RFC2292(bis) compliance)

   *	Kazunori MIYAZAWA @USAGI:	change process style to use ip6_append_data
   *
   *	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/errno.h>
  #include <linux/types.h>
  #include <linux/socket.h>

  #include <linux/slab.h>

  #include <linux/sockios.h>

  #include <linux/net.h>
  #include <linux/in6.h>
  #include <linux/netdevice.h>
  #include <linux/if_arp.h>
  #include <linux/icmpv6.h>
  #include <linux/netfilter.h>
  #include <linux/netfilter_ipv6.h>

  #include <linux/skbuff.h>

  #include <linux/compat.h>

  #include <linux/uaccess.h>

  #include <asm/ioctls.h>

  #include <net/net_namespace.h>

  #include <net/ip.h>
  #include <net/sock.h>
  #include <net/snmp.h>
  
  #include <net/ipv6.h>
  #include <net/ndisc.h>
  #include <net/protocol.h>
  #include <net/ip6_route.h>
  #include <net/ip6_checksum.h>
  #include <net/addrconf.h>
  #include <net/transp_v6.h>
  #include <net/udp.h>
  #include <net/inet_common.h>

  #include <net/tcp_states.h>

  #if IS_ENABLED(CONFIG_IPV6_MIP6)

  #include <net/mip6.h>
  #endif

  #include <linux/mroute6.h>

  #include <net/raw.h>

  #include <net/rawv6.h>
  #include <net/xfrm.h>
  
  #include <linux/proc_fs.h>
  #include <linux/seq_file.h>

  #include <linux/export.h>

  #define	ICMPV6_HDRLEN	4	/* ICMPv6 header, RFC 4443 Section 2.1 */

  struct raw_hashinfo raw_v6_hashinfo = {

  	.lock = __RW_LOCK_UNLOCKED(raw_v6_hashinfo.lock),

  };

  EXPORT_SYMBOL_GPL(raw_v6_hashinfo);

  struct sock *__raw_v6_lookup(struct net *net, struct sock *sk,

  		unsigned short num, const struct in6_addr *loc_addr,

  		const struct in6_addr *rmt_addr, int dif, int sdif)

  {

  	bool is_multicast = ipv6_addr_is_multicast(loc_addr);

  	sk_for_each_from(sk)

  		if (inet_sk(sk)->inet_num == num) {

  			if (!net_eq(sock_net(sk), net))

  				continue;

  			if (!ipv6_addr_any(&sk->sk_v6_daddr) &&
  			    !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr))

  				continue;

  			if (sk->sk_bound_dev_if &&
  			    sk->sk_bound_dev_if != dif &&
  			    sk->sk_bound_dev_if != sdif)

  				continue;

  			if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
  				if (ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr))

  					goto found;
  				if (is_multicast &&
  				    inet6_mc_check(sk, loc_addr, rmt_addr))
  					goto found;
  				continue;
  			}
  			goto found;
  		}
  	sk = NULL;
  found:
  	return sk;
  }

  EXPORT_SYMBOL_GPL(__raw_v6_lookup);

  
  /*
   *	0 - deliver
   *	1 - block
   */

  static int icmpv6_filter(const struct sock *sk, const struct sk_buff *skb)

  {

  	struct icmp6hdr _hdr;

  	const struct icmp6hdr *hdr;

  	/* We require only the four bytes of the ICMPv6 header, not any
  	 * additional bytes of message body in "struct icmp6hdr".
  	 */

  	hdr = skb_header_pointer(skb, skb_transport_offset(skb),

  				 ICMPV6_HDRLEN, &_hdr);

  	if (hdr) {
  		const __u32 *data = &raw6_sk(sk)->filter.data[0];
  		unsigned int type = hdr->icmp6_type;

  		return (data[type >> 5] & (1U << (type & 31))) != 0;

  	}

  	return 1;

  }

  #if IS_ENABLED(CONFIG_IPV6_MIP6)

  typedef int mh_filter_t(struct sock *sock, struct sk_buff *skb);

  static mh_filter_t __rcu *mh_filter __read_mostly;
  
  int rawv6_mh_filter_register(mh_filter_t filter)

  {

  	rcu_assign_pointer(mh_filter, filter);

  	return 0;
  }
  EXPORT_SYMBOL(rawv6_mh_filter_register);

  int rawv6_mh_filter_unregister(mh_filter_t filter)

  {

  	RCU_INIT_POINTER(mh_filter, NULL);

  	synchronize_rcu();
  	return 0;
  }
  EXPORT_SYMBOL(rawv6_mh_filter_unregister);
  
  #endif

  /*
   *	demultiplex raw sockets.
   *	(should consider queueing the skb in the sock receive_queue
   *	without calling rawv6.c)
   *
   *	Caller owns SKB so we must make clones.
   */

  static bool ipv6_raw_deliver(struct sk_buff *skb, int nexthdr)

  {

  	const struct in6_addr *saddr;
  	const struct in6_addr *daddr;

  	struct sock *sk;

  	bool delivered = false;

  	__u8 hash;

  	struct net *net;

  	saddr = &ipv6_hdr(skb)->saddr;

  	daddr = saddr + 1;

  	hash = nexthdr & (RAW_HTABLE_SIZE - 1);

  	read_lock(&raw_v6_hashinfo.lock);
  	sk = sk_head(&raw_v6_hashinfo.ht[hash]);

  	if (!sk)

  		goto out;

  	net = dev_net(skb->dev);

  	sk = __raw_v6_lookup(net, sk, nexthdr, daddr, saddr,
  			     inet6_iif(skb), inet6_sdif(skb));

  
  	while (sk) {

  		int filtered;

  		delivered = true;

  		switch (nexthdr) {
  		case IPPROTO_ICMPV6:
  			filtered = icmpv6_filter(sk, skb);
  			break;

  #if IS_ENABLED(CONFIG_IPV6_MIP6)

  		case IPPROTO_MH:

  		{

  			/* XXX: To validate MH only once for each packet,
  			 * this is placed here. It should be after checking
  			 * xfrm policy, however it doesn't. The checking xfrm
  			 * policy is placed in rawv6_rcv() because it is
  			 * required for each socket.
  			 */

  			mh_filter_t *filter;

  
  			filter = rcu_dereference(mh_filter);

  			filtered = filter ? (*filter)(sk, skb) : 0;

  			break;

  		}

  #endif
  		default:
  			filtered = 0;
  			break;
  		}
  
  		if (filtered < 0)
  			break;
  		if (filtered == 0) {

  			struct sk_buff *clone = skb_clone(skb, GFP_ATOMIC);
  
  			/* Not releasing hash table! */

  			if (clone) {
  				nf_reset(clone);

  				rawv6_rcv(sk, clone);

  			}

  		}

  		sk = __raw_v6_lookup(net, sk_next(sk), nexthdr, daddr, saddr,

  				     inet6_iif(skb), inet6_sdif(skb));

  	}
  out:

  	read_unlock(&raw_v6_hashinfo.lock);

  	return delivered;

  }

  bool raw6_local_deliver(struct sk_buff *skb, int nexthdr)

  {
  	struct sock *raw_sk;

  	raw_sk = sk_head(&raw_v6_hashinfo.ht[nexthdr & (RAW_HTABLE_SIZE - 1)]);

  	if (raw_sk && !ipv6_raw_deliver(skb, nexthdr))
  		raw_sk = NULL;
  
  	return raw_sk != NULL;
  }

  /* This cleans up af_inet6 a bit. -DaveM */
  static int rawv6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
  {
  	struct inet_sock *inet = inet_sk(sk);
  	struct ipv6_pinfo *np = inet6_sk(sk);
  	struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;

  	__be32 v4addr = 0;

  	int addr_type;
  	int err;
  
  	if (addr_len < SIN6_LEN_RFC2133)
  		return -EINVAL;

  
  	if (addr->sin6_family != AF_INET6)
  		return -EINVAL;

  	addr_type = ipv6_addr_type(&addr->sin6_addr);
  
  	/* Raw sockets are IPv6 only */
  	if (addr_type == IPV6_ADDR_MAPPED)

  		return -EADDRNOTAVAIL;

  
  	lock_sock(sk);
  
  	err = -EINVAL;
  	if (sk->sk_state != TCP_CLOSE)
  		goto out;

  	rcu_read_lock();

  	/* Check if the address belongs to the host. */
  	if (addr_type != IPV6_ADDR_ANY) {
  		struct net_device *dev = NULL;

  		if (__ipv6_addr_needs_scope_id(addr_type)) {

  			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)

  				goto out_unlock;

  			err = -ENODEV;
  			dev = dev_get_by_index_rcu(sock_net(sk),
  						   sk->sk_bound_dev_if);
  			if (!dev)
  				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) &&
  		    !sock_net(sk)->ipv6.sysctl.ip_nonlocal_bind) {

  			err = -EADDRNOTAVAIL;

  			if (!ipv6_chk_addr(sock_net(sk), &addr->sin6_addr,

  					   dev, 0)) {

  				goto out_unlock;

  			}
  		}

  	}

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

  	sk->sk_v6_rcv_saddr = addr->sin6_addr;

  	if (!(addr_type & IPV6_ADDR_MULTICAST))

  		np->saddr = addr->sin6_addr;

  	err = 0;

  out_unlock:
  	rcu_read_unlock();

  out:
  	release_sock(sk);
  	return err;
  }

  static void rawv6_err(struct sock *sk, struct sk_buff *skb,

  	       struct inet6_skb_parm *opt,

  	       u8 type, u8 code, int offset, __be32 info)

  {
  	struct inet_sock *inet = inet_sk(sk);
  	struct ipv6_pinfo *np = inet6_sk(sk);
  	int err;
  	int harderr;
  
  	/* Report error on raw socket, if:
  	   1. User requested recverr.
  	   2. Socket is connected (otherwise the error indication
  	      is useless without recverr and error is hard.
  	 */
  	if (!np->recverr && sk->sk_state != TCP_ESTABLISHED)
  		return;
  
  	harderr = icmpv6_err_convert(type, code, &err);

  	if (type == ICMPV6_PKT_TOOBIG) {
  		ip6_sk_update_pmtu(skb, sk, info);

  		harderr = (np->pmtudisc == IPV6_PMTUDISC_DO);

  	}

  	if (type == NDISC_REDIRECT) {

  		ip6_sk_redirect(skb, sk);

  		return;
  	}

  	if (np->recverr) {
  		u8 *payload = skb->data;
  		if (!inet->hdrincl)
  			payload += offset;
  		ipv6_icmp_error(sk, skb, err, 0, ntohl(info), payload);
  	}
  
  	if (np->recverr || harderr) {
  		sk->sk_err = err;
  		sk->sk_error_report(sk);
  	}
  }

  void raw6_icmp_error(struct sk_buff *skb, int nexthdr,

  		u8 type, u8 code, int inner_offset, __be32 info)

  {
  	struct sock *sk;
  	int hash;

  	const struct in6_addr *saddr, *daddr;

  	struct net *net;

  	hash = nexthdr & (RAW_HTABLE_SIZE - 1);

  	read_lock(&raw_v6_hashinfo.lock);
  	sk = sk_head(&raw_v6_hashinfo.ht[hash]);

  	if (sk) {

  		/* Note: ipv6_hdr(skb) != skb->data */

  		const struct ipv6hdr *ip6h = (const struct ipv6hdr *)skb->data;

  		saddr = &ip6h->saddr;
  		daddr = &ip6h->daddr;

  		net = dev_net(skb->dev);

  		while ((sk = __raw_v6_lookup(net, sk, nexthdr, saddr, daddr,

  					     inet6_iif(skb), inet6_iif(skb)))) {

  			rawv6_err(sk, skb, NULL, type, code,
  					inner_offset, info);
  			sk = sk_next(sk);
  		}
  	}

  	read_unlock(&raw_v6_hashinfo.lock);

  }

  static inline int rawv6_rcv_skb(struct sock *sk, struct sk_buff *skb)

  {

  	if ((raw6_sk(sk)->checksum || rcu_access_pointer(sk->sk_filter)) &&

  	    skb_checksum_complete(skb)) {

  		atomic_inc(&sk->sk_drops);

  		kfree_skb(skb);

  		return NET_RX_DROP;

  	}
  
  	/* Charge it to the socket. */

  	skb_dst_drop(skb);
  	if (sock_queue_rcv_skb(sk, skb) < 0) {

  		kfree_skb(skb);

  		return NET_RX_DROP;

  	}
  
  	return 0;
  }
  
  /*

   *	This is next to useless...

   *	if we demultiplex in network layer we don't need the extra call

   *	just to queue the skb...
   *	maybe we could have the network decide upon a hint if it

   *	should call raw_rcv for demultiplexing
   */
  int rawv6_rcv(struct sock *sk, struct sk_buff *skb)
  {
  	struct inet_sock *inet = inet_sk(sk);
  	struct raw6_sock *rp = raw6_sk(sk);

  	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {

  		atomic_inc(&sk->sk_drops);

  		kfree_skb(skb);
  		return NET_RX_DROP;
  	}

  
  	if (!rp->checksum)
  		skb->ip_summed = CHECKSUM_UNNECESSARY;

  	if (skb->ip_summed == CHECKSUM_COMPLETE) {

  		skb_postpull_rcsum(skb, skb_network_header(skb),

  				   skb_network_header_len(skb));

  		if (!csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
  				     &ipv6_hdr(skb)->daddr,

  				     skb->len, inet->inet_num, skb->csum))

  			skb->ip_summed = CHECKSUM_UNNECESSARY;

  	}

  	if (!skb_csum_unnecessary(skb))

  		skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
  							 &ipv6_hdr(skb)->daddr,
  							 skb->len,

  							 inet->inet_num, 0));

  
  	if (inet->hdrincl) {

  		if (skb_checksum_complete(skb)) {

  			atomic_inc(&sk->sk_drops);

  			kfree_skb(skb);

  			return NET_RX_DROP;

  		}

  	}
  
  	rawv6_rcv_skb(sk, skb);
  	return 0;
  }
  
  
  /*
   *	This should be easy, if there is something there
   *	we return it, otherwise we block.
   */

  static int rawv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
  			 int noblock, int flags, int *addr_len)

  {
  	struct ipv6_pinfo *np = inet6_sk(sk);

  	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);

  	struct sk_buff *skb;
  	size_t copied;
  	int err;
  
  	if (flags & MSG_OOB)
  		return -EOPNOTSUPP;

  	if (flags & MSG_ERRQUEUE)

  		return ipv6_recv_error(sk, msg, len, addr_len);

  	if (np->rxpmtu && np->rxopt.bits.rxpmtu)

  		return ipv6_recv_rxpmtu(sk, msg, len, addr_len);

  	skb = skb_recv_datagram(sk, flags, noblock, &err);
  	if (!skb)
  		goto out;
  
  	copied = skb->len;

  	if (copied > len) {
  		copied = len;
  		msg->msg_flags |= MSG_TRUNC;
  	}

  	if (skb_csum_unnecessary(skb)) {

  		err = skb_copy_datagram_msg(skb, 0, msg, copied);

  	} else if (msg->msg_flags&MSG_TRUNC) {

  		if (__skb_checksum_complete(skb))

  			goto csum_copy_err;

  		err = skb_copy_datagram_msg(skb, 0, msg, copied);

  	} else {

  		err = skb_copy_and_csum_datagram_msg(skb, 0, msg);

  		if (err == -EINVAL)
  			goto csum_copy_err;
  	}
  	if (err)
  		goto out_free;
  
  	/* Copy the address. */
  	if (sin6) {
  		sin6->sin6_family = AF_INET6;

  		sin6->sin6_port = 0;

  		sin6->sin6_addr = ipv6_hdr(skb)->saddr;

  		sin6->sin6_flowinfo = 0;

  		sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr,

  							  inet6_iif(skb));

  		*addr_len = sizeof(*sin6);

  	}

  	sock_recv_ts_and_drops(msg, sk, skb);

  
  	if (np->rxopt.all)

  		ip6_datagram_recv_ctl(sk, msg, skb);

  
  	err = copied;
  	if (flags & MSG_TRUNC)
  		err = skb->len;
  
  out_free:
  	skb_free_datagram(sk, skb);
  out:
  	return err;
  
  csum_copy_err:

  	skb_kill_datagram(sk, skb, flags);

  
  	/* Error for blocking case is chosen to masquerade
  	   as some normal condition.
  	 */
  	err = (flags&MSG_DONTWAIT) ? -EAGAIN : -EHOSTUNREACH;

  	goto out;

  }

  static int rawv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6,

  				     struct raw6_sock *rp)

  {
  	struct sk_buff *skb;
  	int err = 0;

  	int offset;
  	int len;

  	int total_len;

  	__wsum tmp_csum;
  	__sum16 csum;

  
  	if (!rp->checksum)
  		goto send;

  	skb = skb_peek(&sk->sk_write_queue);
  	if (!skb)

  		goto out;

  	offset = rp->offset;

  	total_len = inet_sk(sk)->cork.base.length;

  	if (offset >= total_len - 1) {

  		err = -EINVAL;

  		ip6_flush_pending_frames(sk);

  		goto out;
  	}
  
  	/* should be check HW csum miyazawa */
  	if (skb_queue_len(&sk->sk_write_queue) == 1) {
  		/*
  		 * Only one fragment on the socket.
  		 */
  		tmp_csum = skb->csum;
  	} else {

  		struct sk_buff *csum_skb = NULL;

  		tmp_csum = 0;
  
  		skb_queue_walk(&sk->sk_write_queue, skb) {
  			tmp_csum = csum_add(tmp_csum, skb->csum);

  
  			if (csum_skb)
  				continue;

  			len = skb->len - skb_transport_offset(skb);

  			if (offset >= len) {
  				offset -= len;
  				continue;
  			}
  
  			csum_skb = skb;

  		}

  
  		skb = csum_skb;

  	}

  	offset += skb_transport_offset(skb);

  	err = skb_copy_bits(skb, offset, &csum, 2);
  	if (err < 0) {
  		ip6_flush_pending_frames(sk);
  		goto out;
  	}

  	/* in case cksum was not initialized */

  	if (unlikely(csum))

  		tmp_csum = csum_sub(tmp_csum, csum_unfold(csum));

  	csum = csum_ipv6_magic(&fl6->saddr, &fl6->daddr,
  			       total_len, fl6->flowi6_proto, tmp_csum);

  	if (csum == 0 && fl6->flowi6_proto == IPPROTO_UDP)

  		csum = CSUM_MANGLED_0;

  	BUG_ON(skb_store_bits(skb, offset, &csum, 2));

  send:
  	err = ip6_push_pending_frames(sk);
  out:
  	return err;
  }

  static int rawv6_send_hdrinc(struct sock *sk, struct msghdr *msg, int length,

  			struct flowi6 *fl6, struct dst_entry **dstp,

  			unsigned int flags)
  {

  	struct ipv6_pinfo *np = inet6_sk(sk);

  	struct net *net = sock_net(sk);

  	struct ipv6hdr *iph;
  	struct sk_buff *skb;

  	int err;

  	struct rt6_info *rt = (struct rt6_info *)*dstp;

  	int hlen = LL_RESERVED_SPACE(rt->dst.dev);
  	int tlen = rt->dst.dev->needed_tailroom;

  	if (length > rt->dst.dev->mtu) {

  		ipv6_local_error(sk, EMSGSIZE, fl6, rt->dst.dev->mtu);

  		return -EMSGSIZE;
  	}

  	if (length < sizeof(struct ipv6hdr))
  		return -EINVAL;

  	if (flags&MSG_PROBE)
  		goto out;

  	skb = sock_alloc_send_skb(sk,

  				  length + hlen + tlen + 15,

  				  flags & MSG_DONTWAIT, &err);

  	if (!skb)

  		goto error;

  	skb_reserve(skb, hlen);

  	skb->protocol = htons(ETH_P_IPV6);

  	skb->priority = sk->sk_priority;

  	skb->mark = sk->sk_mark;

  	skb_put(skb, length);
  	skb_reset_network_header(skb);

  	iph = ipv6_hdr(skb);

  
  	skb->ip_summed = CHECKSUM_NONE;

  	if (flags & MSG_CONFIRM)
  		skb_set_dst_pending_confirm(skb, 1);

  	skb->transport_header = skb->network_header;

  	err = memcpy_from_msg(iph, msg, length);

  	if (err) {
  		err = -EFAULT;
  		kfree_skb(skb);
  		goto error;
  	}
  
  	skb_dst_set(skb, &rt->dst);
  	*dstp = NULL;

  	/* if egress device is enslaved to an L3 master device pass the
  	 * skb to its handler for processing
  	 */
  	skb = l3mdev_ip6_out(sk, skb);
  	if (unlikely(!skb))
  		return 0;

  	/* Acquire rcu_read_lock() in case we need to use rt->rt6i_idev
  	 * in the error path. Since skb has been freed, the dst could
  	 * have been queued for deletion.
  	 */
  	rcu_read_lock();

  	IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len);

  	err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk, skb,

  		      NULL, rt->dst.dev, dst_output);

  	if (err > 0)

  		err = net_xmit_errno(err);

  	if (err) {
  		IP6_INC_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
  		rcu_read_unlock();
  		goto error_check;
  	}
  	rcu_read_unlock();

  out:
  	return 0;

  error:

  	IP6_INC_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);

  error_check:

  	if (err == -ENOBUFS && !np->recverr)
  		err = 0;

  	return err;

  }

  struct raw6_frag_vec {
  	struct msghdr *msg;
  	int hlen;
  	char c[4];
  };
  
  static int rawv6_probe_proto_opt(struct raw6_frag_vec *rfv, struct flowi6 *fl6)

  {

  	int err = 0;
  	switch (fl6->flowi6_proto) {
  	case IPPROTO_ICMPV6:
  		rfv->hlen = 2;
  		err = memcpy_from_msg(rfv->c, rfv->msg, rfv->hlen);
  		if (!err) {
  			fl6->fl6_icmp_type = rfv->c[0];
  			fl6->fl6_icmp_code = rfv->c[1];
  		}
  		break;
  	case IPPROTO_MH:
  		rfv->hlen = 4;
  		err = memcpy_from_msg(rfv->c, rfv->msg, rfv->hlen);
  		if (!err)
  			fl6->fl6_mh_type = rfv->c[2];
  	}
  	return err;
  }

  static int raw6_getfrag(void *from, char *to, int offset, int len, int odd,
  		       struct sk_buff *skb)
  {
  	struct raw6_frag_vec *rfv = from;
  
  	if (offset < rfv->hlen) {
  		int copy = min(rfv->hlen - offset, len);
  
  		if (skb->ip_summed == CHECKSUM_PARTIAL)
  			memcpy(to, rfv->c + offset, copy);
  		else
  			skb->csum = csum_block_add(
  				skb->csum,
  				csum_partial_copy_nocheck(rfv->c + offset,
  							  to, copy, 0),
  				odd);
  
  		odd = 0;
  		offset += copy;
  		to += copy;
  		len -= copy;
  
  		if (!len)
  			return 0;
  	}

  	offset -= rfv->hlen;

  	return ip_generic_getfrag(rfv->msg, to, offset, len, odd, skb);

  }

  static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)

  {

  	struct ipv6_txoptions *opt_to_free = NULL;

  	struct ipv6_txoptions opt_space;

  	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);

  	struct in6_addr *daddr, *final_p, final;

  	struct inet_sock *inet = inet_sk(sk);
  	struct ipv6_pinfo *np = inet6_sk(sk);
  	struct raw6_sock *rp = raw6_sk(sk);
  	struct ipv6_txoptions *opt = NULL;
  	struct ip6_flowlabel *flowlabel = NULL;
  	struct dst_entry *dst = NULL;

  	struct raw6_frag_vec rfv;

  	struct flowi6 fl6;

  	struct sockcm_cookie sockc;

  	struct ipcm6_cookie ipc6;

  	int addr_len = msg->msg_namelen;

  	u16 proto;
  	int err;
  
  	/* Rough check on arithmetic overflow,

  	   better check is made in ip6_append_data().

  	 */

  	if (len > INT_MAX)

  		return -EMSGSIZE;
  
  	/* Mirror BSD error message compatibility */

  	if (msg->msg_flags & MSG_OOB)

  		return -EOPNOTSUPP;
  
  	/*

  	 *	Get and verify the address.

  	 */

  	memset(&fl6, 0, sizeof(fl6));

  	fl6.flowi6_mark = sk->sk_mark;

  	fl6.flowi6_uid = sk->sk_uid;

  	ipc6.hlimit = -1;
  	ipc6.tclass = -1;
  	ipc6.dontfrag = -1;
  	ipc6.opt = NULL;

  	if (sin6) {

  		if (addr_len < SIN6_LEN_RFC2133)

  			return -EINVAL;

  		if (sin6->sin6_family && sin6->sin6_family != AF_INET6)

  			return -EAFNOSUPPORT;

  
  		/* port is the proto value [0..255] carried in nexthdr */
  		proto = ntohs(sin6->sin6_port);
  
  		if (!proto)

  			proto = inet->inet_num;
  		else if (proto != inet->inet_num)

  			return -EINVAL;

  
  		if (proto > 255)

  			return -EINVAL;

  
  		daddr = &sin6->sin6_addr;
  		if (np->sndflow) {

  			fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK;
  			if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
  				flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);

  				if (!flowlabel)

  					return -EINVAL;

  			}
  		}
  
  		/*
  		 * Otherwise it will be difficult to maintain
  		 * sk->sk_dst_cache.
  		 */
  		if (sk->sk_state == TCP_ESTABLISHED &&

  		    ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
  			daddr = &sk->sk_v6_daddr;

  
  		if (addr_len >= sizeof(struct sockaddr_in6) &&
  		    sin6->sin6_scope_id &&

  		    __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr)))

  			fl6.flowi6_oif = sin6->sin6_scope_id;

  	} else {

  		if (sk->sk_state != TCP_ESTABLISHED)

  			return -EDESTADDRREQ;

  		proto = inet->inet_num;

  		daddr = &sk->sk_v6_daddr;

  		fl6.flowlabel = np->flow_label;

  	}

  	if (fl6.flowi6_oif == 0)
  		fl6.flowi6_oif = sk->sk_bound_dev_if;

  	sockc.tsflags = sk->sk_tsflags;

  	if (msg->msg_controllen) {
  		opt = &opt_space;
  		memset(opt, 0, sizeof(struct ipv6_txoptions));
  		opt->tot_len = sizeof(struct ipv6_txoptions);

  		ipc6.opt = opt;

  		err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, &sockc);

  		if (err < 0) {
  			fl6_sock_release(flowlabel);
  			return err;
  		}

  		if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) {
  			flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);

  			if (!flowlabel)

  				return -EINVAL;
  		}
  		if (!(opt->opt_nflen|opt->opt_flen))
  			opt = NULL;
  	}

  	if (!opt) {
  		opt = txopt_get(np);
  		opt_to_free = opt;

  	}

  	if (flowlabel)
  		opt = fl6_merge_options(&opt_space, flowlabel, opt);
  	opt = ipv6_fixup_options(&opt_space, opt);

  	fl6.flowi6_proto = proto;

  	rfv.msg = msg;
  	rfv.hlen = 0;
  	err = rawv6_probe_proto_opt(&rfv, &fl6);

  	if (err)
  		goto out;

  	if (!ipv6_addr_any(daddr))

  		fl6.daddr = *daddr;

  	else

  		fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
  	if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))

  		fl6.saddr = np->saddr;

  	final_p = fl6_update_dst(&fl6, opt, &final);

  	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
  		fl6.flowi6_oif = np->mcast_oif;

  	else if (!fl6.flowi6_oif)
  		fl6.flowi6_oif = np->ucast_oif;

  	security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));

  	if (inet->hdrincl)
  		fl6.flowi6_flags |= FLOWI_FLAG_KNOWN_NH;

  	if (ipc6.tclass < 0)
  		ipc6.tclass = np->tclass;
  
  	fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);

  	dst = ip6_dst_lookup_flow(sk, &fl6, final_p);

  	if (IS_ERR(dst)) {
  		err = PTR_ERR(dst);

  		goto out;

  	}

  	if (ipc6.hlimit < 0)
  		ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);

  	if (ipc6.dontfrag < 0)
  		ipc6.dontfrag = np->dontfrag;

  	if (msg->msg_flags&MSG_CONFIRM)
  		goto do_confirm;
  
  back_from_confirm:

  	if (inet->hdrincl)

  		err = rawv6_send_hdrinc(sk, msg, len, &fl6, &dst, msg->msg_flags);

  	else {

  		ipc6.opt = opt;

  		lock_sock(sk);

  		err = ip6_append_data(sk, raw6_getfrag, &rfv,

  			len, 0, &ipc6, &fl6, (struct rt6_info *)dst,
  			msg->msg_flags, &sockc);

  
  		if (err)
  			ip6_flush_pending_frames(sk);
  		else if (!(msg->msg_flags & MSG_MORE))

  			err = rawv6_push_pending_frames(sk, &fl6, rp);

  		release_sock(sk);

  	}
  done:

  	dst_release(dst);

  out:

  	fl6_sock_release(flowlabel);

  	txopt_put(opt_to_free);

  	return err < 0 ? err : len;

  do_confirm:

  	if (msg->msg_flags & MSG_PROBE)
  		dst_confirm_neigh(dst, &fl6.daddr);

  	if (!(msg->msg_flags & MSG_PROBE) || len)
  		goto back_from_confirm;
  	err = 0;
  	goto done;
  }

  static int rawv6_seticmpfilter(struct sock *sk, int level, int optname,

  			       char __user *optval, int optlen)
  {
  	switch (optname) {
  	case ICMPV6_FILTER:
  		if (optlen > sizeof(struct icmp6_filter))
  			optlen = sizeof(struct icmp6_filter);
  		if (copy_from_user(&raw6_sk(sk)->filter, optval, optlen))
  			return -EFAULT;
  		return 0;
  	default:
  		return -ENOPROTOOPT;

  	}

  
  	return 0;
  }

  static int rawv6_geticmpfilter(struct sock *sk, int level, int optname,

  			       char __user *optval, int __user *optlen)
  {
  	int len;
  
  	switch (optname) {
  	case ICMPV6_FILTER:
  		if (get_user(len, optlen))
  			return -EFAULT;
  		if (len < 0)
  			return -EINVAL;
  		if (len > sizeof(struct icmp6_filter))
  			len = sizeof(struct icmp6_filter);
  		if (put_user(len, optlen))
  			return -EFAULT;
  		if (copy_to_user(optval, &raw6_sk(sk)->filter, len))
  			return -EFAULT;
  		return 0;
  	default:
  		return -ENOPROTOOPT;

  	}

  
  	return 0;
  }

  static int do_rawv6_setsockopt(struct sock *sk, int level, int optname,

  			    char __user *optval, unsigned int optlen)

  {
  	struct raw6_sock *rp = raw6_sk(sk);
  	int val;

  	if (get_user(val, (int __user *)optval))

  		return -EFAULT;
  
  	switch (optname) {

  	case IPV6_HDRINCL:
  		if (sk->sk_type != SOCK_RAW)
  			return -EINVAL;
  		inet_sk(sk)->hdrincl = !!val;
  		return 0;

  	case IPV6_CHECKSUM:
  		if (inet_sk(sk)->inet_num == IPPROTO_ICMPV6 &&
  		    level == IPPROTO_IPV6) {
  			/*
  			 * RFC3542 tells that IPV6_CHECKSUM socket
  			 * option in the IPPROTO_IPV6 level is not
  			 * allowed on ICMPv6 sockets.
  			 * If you want to set it, use IPPROTO_RAW
  			 * level IPV6_CHECKSUM socket option
  			 * (Linux extension).
  			 */
  			return -EINVAL;
  		}

  		/* You may get strange result with a positive odd offset;
  		   RFC2292bis agrees with me. */
  		if (val > 0 && (val&1))
  			return -EINVAL;
  		if (val < 0) {
  			rp->checksum = 0;
  		} else {
  			rp->checksum = 1;
  			rp->offset = val;
  		}

  		return 0;

  	default:
  		return -ENOPROTOOPT;

  	}
  }

  static int rawv6_setsockopt(struct sock *sk, int level, int optname,

  			  char __user *optval, unsigned int optlen)

  {

  	switch (level) {
  	case SOL_RAW:
  		break;

  	case SOL_ICMPV6:
  		if (inet_sk(sk)->inet_num != IPPROTO_ICMPV6)
  			return -EOPNOTSUPP;
  		return rawv6_seticmpfilter(sk, level, optname, optval, optlen);
  	case SOL_IPV6:

  		if (optname == IPV6_CHECKSUM ||
  		    optname == IPV6_HDRINCL)

  			break;
  	default:
  		return ipv6_setsockopt(sk, level, optname, optval, optlen);

  	}

  	return do_rawv6_setsockopt(sk, level, optname, optval, optlen);
  }
  
  #ifdef CONFIG_COMPAT
  static int compat_rawv6_setsockopt(struct sock *sk, int level, int optname,

  				   char __user *optval, unsigned int optlen)

  {

  	switch (level) {
  	case SOL_RAW:
  		break;
  	case SOL_ICMPV6:

  		if (inet_sk(sk)->inet_num != IPPROTO_ICMPV6)

  			return -EOPNOTSUPP;
  		return rawv6_seticmpfilter(sk, level, optname, optval, optlen);
  	case SOL_IPV6:

  		if (optname == IPV6_CHECKSUM ||
  		    optname == IPV6_HDRINCL)

  			break;

  	default:
  		return compat_ipv6_setsockopt(sk, level, optname,
  					      optval, optlen);

  	}

  	return do_rawv6_setsockopt(sk, level, optname, optval, optlen);
  }
  #endif
  
  static int do_rawv6_getsockopt(struct sock *sk, int level, int optname,
  			    char __user *optval, int __user *optlen)
  {
  	struct raw6_sock *rp = raw6_sk(sk);
  	int val, len;

  	if (get_user(len, optlen))

  		return -EFAULT;
  
  	switch (optname) {

  	case IPV6_HDRINCL:
  		val = inet_sk(sk)->hdrincl;
  		break;

  	case IPV6_CHECKSUM:

  		/*
  		 * We allow getsockopt() for IPPROTO_IPV6-level
  		 * IPV6_CHECKSUM socket option on ICMPv6 sockets
  		 * since RFC3542 is silent about it.
  		 */

  		if (rp->checksum == 0)
  			val = -1;
  		else
  			val = rp->offset;
  		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;
  }

  static int rawv6_getsockopt(struct sock *sk, int level, int optname,
  			  char __user *optval, int __user *optlen)
  {

  	switch (level) {
  	case SOL_RAW:
  		break;

  	case SOL_ICMPV6:
  		if (inet_sk(sk)->inet_num != IPPROTO_ICMPV6)
  			return -EOPNOTSUPP;
  		return rawv6_geticmpfilter(sk, level, optname, optval, optlen);
  	case SOL_IPV6:

  		if (optname == IPV6_CHECKSUM ||
  		    optname == IPV6_HDRINCL)

  			break;
  	default:
  		return ipv6_getsockopt(sk, level, optname, optval, optlen);

  	}

  	return do_rawv6_getsockopt(sk, level, optname, optval, optlen);
  }
  
  #ifdef CONFIG_COMPAT
  static int compat_rawv6_getsockopt(struct sock *sk, int level, int optname,

  				   char __user *optval, int __user *optlen)

  {

  	switch (level) {
  	case SOL_RAW:
  		break;
  	case SOL_ICMPV6:

  		if (inet_sk(sk)->inet_num != IPPROTO_ICMPV6)

  			return -EOPNOTSUPP;
  		return rawv6_geticmpfilter(sk, level, optname, optval, optlen);
  	case SOL_IPV6:

  		if (optname == IPV6_CHECKSUM ||
  		    optname == IPV6_HDRINCL)

  			break;

  	default:
  		return compat_ipv6_getsockopt(sk, level, optname,
  					      optval, optlen);

  	}

  	return do_rawv6_getsockopt(sk, level, optname, optval, optlen);
  }
  #endif

  static int rawv6_ioctl(struct sock *sk, int cmd, unsigned long arg)
  {

  	switch (cmd) {
  	case SIOCOUTQ: {
  		int amount = sk_wmem_alloc_get(sk);

  		return put_user(amount, (int __user *)arg);
  	}
  	case SIOCINQ: {
  		struct sk_buff *skb;
  		int amount = 0;
  
  		spin_lock_bh(&sk->sk_receive_queue.lock);
  		skb = skb_peek(&sk->sk_receive_queue);

  		if (skb)

  			amount = skb->len;

  		spin_unlock_bh(&sk->sk_receive_queue.lock);
  		return put_user(amount, (int __user *)arg);
  	}

  	default:

  #ifdef CONFIG_IPV6_MROUTE

  		return ip6mr_ioctl(sk, cmd, (void __user *)arg);

  #else

  		return -ENOIOCTLCMD;

  #endif

  	}
  }

  #ifdef CONFIG_COMPAT
  static int compat_rawv6_ioctl(struct sock *sk, unsigned int cmd, unsigned long arg)
  {
  	switch (cmd) {
  	case SIOCOUTQ:
  	case SIOCINQ:
  		return -ENOIOCTLCMD;
  	default:
  #ifdef CONFIG_IPV6_MROUTE
  		return ip6mr_compat_ioctl(sk, cmd, compat_ptr(arg));
  #else
  		return -ENOIOCTLCMD;
  #endif
  	}
  }
  #endif

  static void rawv6_close(struct sock *sk, long timeout)
  {

  	if (inet_sk(sk)->inet_num == IPPROTO_RAW)

  		ip6_ra_control(sk, -1);

  	ip6mr_sk_done(sk);

  	sk_common_release(sk);
  }

  static void raw6_destroy(struct sock *sk)

  {
  	lock_sock(sk);
  	ip6_flush_pending_frames(sk);
  	release_sock(sk);

  	inet6_destroy_sock(sk);

  }

  static int rawv6_init_sk(struct sock *sk)
  {

  	struct raw6_sock *rp = raw6_sk(sk);

  	switch (inet_sk(sk)->inet_num) {

  	case IPPROTO_ICMPV6:

  		rp->checksum = 1;
  		rp->offset   = 2;

  		break;
  	case IPPROTO_MH:
  		rp->checksum = 1;
  		rp->offset   = 4;
  		break;
  	default:
  		break;

  	}

  	return 0;

  }
  
  struct proto rawv6_prot = {

  	.name		   = "RAWv6",
  	.owner		   = THIS_MODULE,
  	.close		   = rawv6_close,

  	.destroy	   = raw6_destroy,

  	.connect	   = ip6_datagram_connect_v6_only,

  	.disconnect	   = __udp_disconnect,

  	.ioctl		   = rawv6_ioctl,
  	.init		   = rawv6_init_sk,

  	.setsockopt	   = rawv6_setsockopt,
  	.getsockopt	   = rawv6_getsockopt,
  	.sendmsg	   = rawv6_sendmsg,
  	.recvmsg	   = rawv6_recvmsg,
  	.bind		   = rawv6_bind,
  	.backlog_rcv	   = rawv6_rcv_skb,

  	.hash		   = raw_hash_sk,
  	.unhash		   = raw_unhash_sk,

  	.obj_size	   = sizeof(struct raw6_sock),

  	.h.raw_hash	   = &raw_v6_hashinfo,

  #ifdef CONFIG_COMPAT

  	.compat_setsockopt = compat_rawv6_setsockopt,
  	.compat_getsockopt = compat_rawv6_getsockopt,

  	.compat_ioctl	   = compat_rawv6_ioctl,

  #endif

  	.diag_destroy	   = raw_abort,

  };
  
  #ifdef CONFIG_PROC_FS

  static int raw6_seq_show(struct seq_file *seq, void *v)
  {

  	if (v == SEQ_START_TOKEN) {
  		seq_puts(seq, IPV6_SEQ_DGRAM_HEADER);
  	} else {
  		struct sock *sp = v;
  		__u16 srcp  = inet_sk(sp)->inet_num;
  		ip6_dgram_sock_seq_show(seq, v, srcp, 0,
  					raw_seq_private(seq)->bucket);
  	}

  	return 0;
  }

  static const struct seq_operations raw6_seq_ops = {

  	.start =	raw_seq_start,
  	.next =		raw_seq_next,
  	.stop =		raw_seq_stop,

  	.show =		raw6_seq_show,
  };
  
  static int raw6_seq_open(struct inode *inode, struct file *file)
  {

  	return raw_seq_open(inode, file, &raw_v6_hashinfo, &raw6_seq_ops);

  }

  static const struct file_operations raw6_seq_fops = {

  	.owner =	THIS_MODULE,
  	.open =		raw6_seq_open,
  	.read =		seq_read,
  	.llseek =	seq_lseek,

  	.release =	seq_release_net,

  };

  static int __net_init raw6_init_net(struct net *net)

  {

  	if (!proc_create("raw6", S_IRUGO, net->proc_net, &raw6_seq_fops))

  		return -ENOMEM;

  	return 0;
  }

  static void __net_exit raw6_exit_net(struct net *net)

  {

  	remove_proc_entry("raw6", net->proc_net);

  }
  
  static struct pernet_operations raw6_net_ops = {
  	.init = raw6_init_net,
  	.exit = raw6_exit_net,
  };
  
  int __init raw6_proc_init(void)
  {
  	return register_pernet_subsys(&raw6_net_ops);
  }

  void raw6_proc_exit(void)
  {

  	unregister_pernet_subsys(&raw6_net_ops);

  }
  #endif	/* CONFIG_PROC_FS */

  
  /* Same as inet6_dgram_ops, sans udp_poll.  */

  const struct proto_ops inet6_sockraw_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		   = datagram_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	   = sock_common_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 struct inet_protosw rawv6_protosw = {
  	.type		= SOCK_RAW,
  	.protocol	= IPPROTO_IP,	/* wild card */
  	.prot		= &rawv6_prot,
  	.ops		= &inet6_sockraw_ops,

  	.flags		= INET_PROTOSW_REUSE,
  };
  
  int __init rawv6_init(void)
  {

  	return inet6_register_protosw(&rawv6_protosw);

  }

  void rawv6_exit(void)

  {
  	inet6_unregister_protosw(&rawv6_protosw);
  }