/*
   * INET		An implementation of the TCP/IP protocol suite for the LINUX
   *		operating system.  INET is implemented using the  BSD Socket
   *		interface as the means of communication with the user level.
   *
   *		RAW - implementation of IP "raw" sockets.
   *

   * Authors:	Ross Biro

   *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
   *
   * Fixes:
   *		Alan Cox	:	verify_area() fixed up
   *		Alan Cox	:	ICMP error handling
   *		Alan Cox	:	EMSGSIZE if you send too big a packet
   *		Alan Cox	: 	Now uses generic datagrams and shared
   *					skbuff library. No more peek crashes,
   *					no more backlogs
   *		Alan Cox	:	Checks sk->broadcast.
   *		Alan Cox	:	Uses skb_free_datagram/skb_copy_datagram
   *		Alan Cox	:	Raw passes ip options too
   *		Alan Cox	:	Setsocketopt added
   *		Alan Cox	:	Fixed error return for broadcasts
   *		Alan Cox	:	Removed wake_up calls
   *		Alan Cox	:	Use ttl/tos
   *		Alan Cox	:	Cleaned up old debugging
   *		Alan Cox	:	Use new kernel side addresses
   *	Arnt Gulbrandsen	:	Fixed MSG_DONTROUTE in raw sockets.
   *		Alan Cox	:	BSD style RAW socket demultiplexing.
   *		Alan Cox	:	Beginnings of mrouted support.
   *		Alan Cox	:	Added IP_HDRINCL option.
   *		Alan Cox	:	Skip broadcast check if BSDism set.
   *		David S. Miller	:	New socket lookup architecture.
   *
   *		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/types.h>

  #include <linux/atomic.h>

  #include <asm/byteorder.h>
  #include <asm/current.h>
  #include <asm/uaccess.h>
  #include <asm/ioctls.h>

  #include <linux/stddef.h>
  #include <linux/slab.h>
  #include <linux/errno.h>

  #include <linux/kernel.h>

  #include <linux/export.h>

  #include <linux/spinlock.h>
  #include <linux/sockios.h>
  #include <linux/socket.h>
  #include <linux/in.h>
  #include <linux/mroute.h>
  #include <linux/netdevice.h>
  #include <linux/in_route.h>
  #include <linux/route.h>

  #include <linux/skbuff.h>

  #include <linux/igmp.h>

  #include <net/net_namespace.h>

  #include <net/dst.h>
  #include <net/sock.h>

  #include <linux/ip.h>
  #include <linux/net.h>
  #include <net/ip.h>
  #include <net/icmp.h>
  #include <net/udp.h>
  #include <net/raw.h>
  #include <net/snmp.h>

  #include <net/tcp_states.h>

  #include <net/inet_common.h>
  #include <net/checksum.h>
  #include <net/xfrm.h>
  #include <linux/rtnetlink.h>
  #include <linux/proc_fs.h>
  #include <linux/seq_file.h>
  #include <linux/netfilter.h>
  #include <linux/netfilter_ipv4.h>

  #include <linux/compat.h>

  #include <linux/uio.h>
  
  struct raw_frag_vec {

  	struct msghdr *msg;

  	union {
  		struct icmphdr icmph;
  		char c[1];
  	} hdr;
  	int hlen;
  };

  static struct raw_hashinfo raw_v4_hashinfo = {

  	.lock = __RW_LOCK_UNLOCKED(raw_v4_hashinfo.lock),

  };

  int raw_hash_sk(struct sock *sk)

  {

  	struct raw_hashinfo *h = sk->sk_prot->h.raw_hash;

  	struct hlist_head *head;

  	head = &h->ht[inet_sk(sk)->inet_num & (RAW_HTABLE_SIZE - 1)];

  
  	write_lock_bh(&h->lock);

  	sk_add_node(sk, head);

  	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);

  	write_unlock_bh(&h->lock);

  
  	return 0;

  }
  EXPORT_SYMBOL_GPL(raw_hash_sk);

  void raw_unhash_sk(struct sock *sk)

  {

  	struct raw_hashinfo *h = sk->sk_prot->h.raw_hash;

  	write_lock_bh(&h->lock);
  	if (sk_del_node_init(sk))

  		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);

  	write_unlock_bh(&h->lock);
  }
  EXPORT_SYMBOL_GPL(raw_unhash_sk);

  static struct sock *__raw_v4_lookup(struct net *net, struct sock *sk,
  		unsigned short num, __be32 raddr, __be32 laddr, int dif)

  {

  	sk_for_each_from(sk) {

  		struct inet_sock *inet = inet_sk(sk);

  		if (net_eq(sock_net(sk), net) && inet->inet_num == num	&&
  		    !(inet->inet_daddr && inet->inet_daddr != raddr) 	&&
  		    !(inet->inet_rcv_saddr && inet->inet_rcv_saddr != laddr) &&

  		    !(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
  			goto found; /* gotcha */
  	}
  	sk = NULL;
  found:
  	return sk;
  }
  
  /*
   *	0 - deliver
   *	1 - block
   */

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

  {

  	struct icmphdr _hdr;
  	const struct icmphdr *hdr;

  	hdr = skb_header_pointer(skb, skb_transport_offset(skb),
  				 sizeof(_hdr), &_hdr);
  	if (!hdr)

  		return 1;

  	if (hdr->type < 32) {

  		__u32 data = raw_sk(sk)->filter.data;

  		return ((1U << hdr->type) & data) != 0;

  	}
  
  	/* Do not block unknown ICMP types */
  	return 0;
  }
  
  /* IP input processing comes here for RAW socket delivery.
   * Caller owns SKB, so we must make clones.
   *
   * RFC 1122: SHOULD pass TOS value up to the transport layer.
   * -> It does. And not only TOS, but all IP header.
   */

  static int raw_v4_input(struct sk_buff *skb, const struct iphdr *iph, int hash)

  {
  	struct sock *sk;
  	struct hlist_head *head;

  	int delivered = 0;

  	struct net *net;

  	read_lock(&raw_v4_hashinfo.lock);
  	head = &raw_v4_hashinfo.ht[hash];

  	if (hlist_empty(head))
  		goto out;

  	net = dev_net(skb->dev);

  	sk = __raw_v4_lookup(net, __sk_head(head), iph->protocol,

  			     iph->saddr, iph->daddr,
  			     skb->dev->ifindex);
  
  	while (sk) {

  		delivered = 1;

  		if ((iph->protocol != IPPROTO_ICMP || !icmp_filter(sk, skb)) &&
  		    ip_mc_sf_allow(sk, iph->daddr, iph->saddr,
  				   skb->dev->ifindex)) {

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

  		sk = __raw_v4_lookup(net, sk_next(sk), iph->protocol,

  				     iph->saddr, iph->daddr,
  				     skb->dev->ifindex);
  	}
  out:

  	read_unlock(&raw_v4_hashinfo.lock);

  	return delivered;

  }

  int raw_local_deliver(struct sk_buff *skb, int protocol)
  {
  	int hash;
  	struct sock *raw_sk;

  	hash = protocol & (RAW_HTABLE_SIZE - 1);
  	raw_sk = sk_head(&raw_v4_hashinfo.ht[hash]);

  
  	/* If there maybe a raw socket we must check - if not we
  	 * don't care less
  	 */
  	if (raw_sk && !raw_v4_input(skb, ip_hdr(skb), hash))
  		raw_sk = NULL;
  
  	return raw_sk != NULL;
  
  }
  
  static void raw_err(struct sock *sk, struct sk_buff *skb, u32 info)

  {
  	struct inet_sock *inet = inet_sk(sk);

  	const int type = icmp_hdr(skb)->type;
  	const int code = icmp_hdr(skb)->code;

  	int err = 0;
  	int harderr = 0;

  	if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
  		ipv4_sk_update_pmtu(skb, sk, info);

  	else if (type == ICMP_REDIRECT) {

  		ipv4_sk_redirect(skb, sk);

  		return;
  	}

  	/* Report error on raw socket, if:
  	   1. User requested ip_recverr.
  	   2. Socket is connected (otherwise the error indication
  	      is useless without ip_recverr and error is hard.
  	 */
  	if (!inet->recverr && sk->sk_state != TCP_ESTABLISHED)
  		return;
  
  	switch (type) {
  	default:
  	case ICMP_TIME_EXCEEDED:
  		err = EHOSTUNREACH;
  		break;
  	case ICMP_SOURCE_QUENCH:
  		return;
  	case ICMP_PARAMETERPROB:
  		err = EPROTO;
  		harderr = 1;
  		break;
  	case ICMP_DEST_UNREACH:
  		err = EHOSTUNREACH;
  		if (code > NR_ICMP_UNREACH)
  			break;
  		err = icmp_err_convert[code].errno;
  		harderr = icmp_err_convert[code].fatal;
  		if (code == ICMP_FRAG_NEEDED) {
  			harderr = inet->pmtudisc != IP_PMTUDISC_DONT;
  			err = EMSGSIZE;
  		}
  	}
  
  	if (inet->recverr) {

  		const struct iphdr *iph = (const struct iphdr *)skb->data;

  		u8 *payload = skb->data + (iph->ihl << 2);
  
  		if (inet->hdrincl)
  			payload = skb->data;
  		ip_icmp_error(sk, skb, err, 0, info, payload);
  	}
  
  	if (inet->recverr || harderr) {
  		sk->sk_err = err;
  		sk->sk_error_report(sk);
  	}
  }

  void raw_icmp_error(struct sk_buff *skb, int protocol, u32 info)
  {
  	int hash;
  	struct sock *raw_sk;

  	const struct iphdr *iph;

  	struct net *net;

  	hash = protocol & (RAW_HTABLE_SIZE - 1);

  	read_lock(&raw_v4_hashinfo.lock);
  	raw_sk = sk_head(&raw_v4_hashinfo.ht[hash]);

  	if (raw_sk) {

  		iph = (const struct iphdr *)skb->data;

  		net = dev_net(skb->dev);

  
  		while ((raw_sk = __raw_v4_lookup(net, raw_sk, protocol,
  						iph->daddr, iph->saddr,

  						skb->dev->ifindex)) != NULL) {
  			raw_err(raw_sk, skb, info);
  			raw_sk = sk_next(raw_sk);

  			iph = (const struct iphdr *)skb->data;

  		}
  	}

  	read_unlock(&raw_v4_hashinfo.lock);

  }

  static int raw_rcv_skb(struct sock *sk, struct sk_buff *skb)

  {
  	/* Charge it to the socket. */

  	ipv4_pktinfo_prepare(sk, skb);

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

  		kfree_skb(skb);
  		return NET_RX_DROP;
  	}
  
  	return NET_RX_SUCCESS;
  }
  
  int raw_rcv(struct sock *sk, struct sk_buff *skb)
  {
  	if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) {

  		atomic_inc(&sk->sk_drops);

  		kfree_skb(skb);
  		return NET_RX_DROP;
  	}

  	nf_reset(skb);

  	skb_push(skb, skb->data - skb_network_header(skb));

  
  	raw_rcv_skb(sk, skb);
  	return 0;
  }

  static int raw_send_hdrinc(struct sock *sk, struct flowi4 *fl4,

  			   struct msghdr *msg, size_t length,

  			   struct rtable **rtp, unsigned int flags,
  			   const struct sockcm_cookie *sockc)

  {
  	struct inet_sock *inet = inet_sk(sk);

  	struct net *net = sock_net(sk);

  	struct iphdr *iph;
  	struct sk_buff *skb;

  	unsigned int iphlen;

  	int err;

  	struct rtable *rt = *rtp;

  	int hlen, tlen;

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

  		ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport,

  			       rt->dst.dev->mtu);

  		return -EMSGSIZE;
  	}
  	if (flags&MSG_PROBE)
  		goto out;

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

  	skb = sock_alloc_send_skb(sk,

  				  length + hlen + tlen + 15,

  				  flags & MSG_DONTWAIT, &err);

  	if (!skb)

  		goto error;

  	skb_reserve(skb, hlen);

  
  	skb->priority = sk->sk_priority;

  	skb->mark = sk->sk_mark;

  	skb_dst_set(skb, &rt->dst);

  	*rtp = NULL;

  	skb_reset_network_header(skb);

  	iph = ip_hdr(skb);

  	skb_put(skb, length);

  
  	skb->ip_summed = CHECKSUM_NONE;

  	sock_tx_timestamp(sk, sockc->tsflags, &skb_shinfo(skb)->tx_flags);

  	skb->transport_header = skb->network_header;

  	err = -EFAULT;

  	if (memcpy_from_msg(iph, msg, length))

  		goto error_free;

  	iphlen = iph->ihl * 4;

  
  	/*
  	 * We don't want to modify the ip header, but we do need to
  	 * be sure that it won't cause problems later along the network
  	 * stack.  Specifically we want to make sure that iph->ihl is a
  	 * sane value.  If ihl points beyond the length of the buffer passed
  	 * in, reject the frame as invalid
  	 */
  	err = -EINVAL;
  	if (iphlen > length)
  		goto error_free;
  
  	if (iphlen >= sizeof(*iph)) {

  		if (!iph->saddr)

  			iph->saddr = fl4->saddr;

  		iph->check   = 0;
  		iph->tot_len = htons(length);
  		if (!iph->id)

  			ip_select_ident(net, skb, NULL);

  
  		iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);

  		skb->transport_header += iphlen;
  		if (iph->protocol == IPPROTO_ICMP &&
  		    length >= iphlen + sizeof(struct icmphdr))
  			icmp_out_count(net, ((struct icmphdr *)
  				skb_transport_header(skb))->type);

  	}

  	err = NF_HOOK(NFPROTO_IPV4, NF_INET_LOCAL_OUT,
  		      net, sk, skb, NULL, rt->dst.dev,

  		      dst_output);

  	if (err > 0)

  		err = net_xmit_errno(err);

  	if (err)
  		goto error;
  out:
  	return 0;

  error_free:

  	kfree_skb(skb);
  error:

  	IP_INC_STATS(net, IPSTATS_MIB_OUTDISCARDS);

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

  	return err;

  }

  static int raw_probe_proto_opt(struct raw_frag_vec *rfv, struct flowi4 *fl4)

  {

  	int err;

  	if (fl4->flowi4_proto != IPPROTO_ICMP)

  		return 0;

  	/* We only need the first two bytes. */

  	rfv->hlen = 2;

  	err = memcpy_from_msg(rfv->hdr.c, rfv->msg, rfv->hlen);

  	if (err)
  		return err;

  	fl4->fl4_icmp_type = rfv->hdr.icmph.type;
  	fl4->fl4_icmp_code = rfv->hdr.icmph.code;

  	return 0;

  }

  static int raw_getfrag(void *from, char *to, int offset, int len, int odd,
  		       struct sk_buff *skb)
  {
  	struct raw_frag_vec *rfv = from;
  
  	if (offset < rfv->hlen) {
  		int copy = min(rfv->hlen - offset, len);
  
  		if (skb->ip_summed == CHECKSUM_PARTIAL)
  			memcpy(to, rfv->hdr.c + offset, copy);
  		else
  			skb->csum = csum_block_add(
  				skb->csum,
  				csum_partial_copy_nocheck(rfv->hdr.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 raw_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)

  {
  	struct inet_sock *inet = inet_sk(sk);

  	struct net *net = sock_net(sk);

  	struct ipcm_cookie ipc;
  	struct rtable *rt = NULL;

  	struct flowi4 fl4;

  	int free = 0;

  	__be32 daddr;

  	__be32 saddr;

  	u8  tos;
  	int err;

  	struct ip_options_data opt_copy;

  	struct raw_frag_vec rfv;

  
  	err = -EMSGSIZE;

  	if (len > 0xFFFF)

  		goto out;
  
  	/*
  	 *	Check the flags.
  	 */
  
  	err = -EOPNOTSUPP;
  	if (msg->msg_flags & MSG_OOB)	/* Mirror BSD error message */
  		goto out;               /* compatibility */

  	/*

  	 *	Get and verify the address.

  	 */
  
  	if (msg->msg_namelen) {

  		DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);

  		err = -EINVAL;
  		if (msg->msg_namelen < sizeof(*usin))
  			goto out;
  		if (usin->sin_family != AF_INET) {

  			pr_info_once("%s: %s forgot to set AF_INET. Fix it!
  ",
  				     __func__, current->comm);

  			err = -EAFNOSUPPORT;
  			if (usin->sin_family)
  				goto out;
  		}
  		daddr = usin->sin_addr.s_addr;
  		/* ANK: I did not forget to get protocol from port field.
  		 * I just do not know, who uses this weirdness.
  		 * IP_HDRINCL is much more convenient.
  		 */
  	} else {
  		err = -EDESTADDRREQ;

  		if (sk->sk_state != TCP_ESTABLISHED)

  			goto out;

  		daddr = inet->inet_daddr;

  	}

  	ipc.sockc.tsflags = sk->sk_tsflags;

  	ipc.addr = inet->inet_saddr;

  	ipc.opt = NULL;

  	ipc.tx_flags = 0;

  	ipc.ttl = 0;
  	ipc.tos = -1;

  	ipc.oif = sk->sk_bound_dev_if;
  
  	if (msg->msg_controllen) {

  		err = ip_cmsg_send(sk, msg, &ipc, false);

  		if (unlikely(err)) {
  			kfree(ipc.opt);

  			goto out;

  		}

  		if (ipc.opt)
  			free = 1;
  	}
  
  	saddr = ipc.addr;
  	ipc.addr = daddr;

  	if (!ipc.opt) {
  		struct ip_options_rcu *inet_opt;
  
  		rcu_read_lock();
  		inet_opt = rcu_dereference(inet->inet_opt);
  		if (inet_opt) {
  			memcpy(&opt_copy, inet_opt,
  			       sizeof(*inet_opt) + inet_opt->opt.optlen);
  			ipc.opt = &opt_copy.opt;
  		}
  		rcu_read_unlock();
  	}

  
  	if (ipc.opt) {
  		err = -EINVAL;
  		/* Linux does not mangle headers on raw sockets,
  		 * so that IP options + IP_HDRINCL is non-sense.
  		 */
  		if (inet->hdrincl)
  			goto done;

  		if (ipc.opt->opt.srr) {

  			if (!daddr)
  				goto done;

  			daddr = ipc.opt->opt.faddr;

  		}
  	}

  	tos = get_rtconn_flags(&ipc, sk);

  	if (msg->msg_flags & MSG_DONTROUTE)
  		tos |= RTO_ONLINK;

  	if (ipv4_is_multicast(daddr)) {

  		if (!ipc.oif)
  			ipc.oif = inet->mc_index;
  		if (!saddr)
  			saddr = inet->mc_addr;

  	} else if (!ipc.oif)
  		ipc.oif = inet->uc_index;

  	flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
  			   RT_SCOPE_UNIVERSE,
  			   inet->hdrincl ? IPPROTO_RAW : sk->sk_protocol,

  			   inet_sk_flowi_flags(sk) |

  			    (inet->hdrincl ? FLOWI_FLAG_KNOWN_NH : 0),

  			   daddr, saddr, 0, 0);

  	if (!inet->hdrincl) {

  		rfv.msg = msg;

  		rfv.hlen = 0;
  
  		err = raw_probe_proto_opt(&rfv, &fl4);

  		if (err)

  			goto done;

  	}
  
  	security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));

  	rt = ip_route_output_flow(net, &fl4, sk);

  	if (IS_ERR(rt)) {
  		err = PTR_ERR(rt);
  		rt = NULL;
  		goto done;

  	}

  
  	err = -EACCES;
  	if (rt->rt_flags & RTCF_BROADCAST && !sock_flag(sk, SOCK_BROADCAST))
  		goto done;
  
  	if (msg->msg_flags & MSG_CONFIRM)
  		goto do_confirm;
  back_from_confirm:
  
  	if (inet->hdrincl)

  		err = raw_send_hdrinc(sk, &fl4, msg, len,

  				      &rt, msg->msg_flags, &ipc.sockc);

  	 else {

  		sock_tx_timestamp(sk, ipc.sockc.tsflags, &ipc.tx_flags);

  		if (!ipc.addr)

  			ipc.addr = fl4.daddr;

  		lock_sock(sk);

  		err = ip_append_data(sk, &fl4, raw_getfrag,
  				     &rfv, len, 0,

  				     &ipc, &rt, msg->msg_flags);

  		if (err)
  			ip_flush_pending_frames(sk);

  		else if (!(msg->msg_flags & MSG_MORE)) {

  			err = ip_push_pending_frames(sk, &fl4);

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

  		release_sock(sk);
  	}
  done:
  	if (free)
  		kfree(ipc.opt);
  	ip_rt_put(rt);

  out:
  	if (err < 0)
  		return err;
  	return len;

  
  do_confirm:

  	dst_confirm(&rt->dst);

  	if (!(msg->msg_flags & MSG_PROBE) || len)
  		goto back_from_confirm;
  	err = 0;
  	goto done;
  }
  
  static void raw_close(struct sock *sk, long timeout)
  {

  	/*

  	 * Raw sockets may have direct kernel references. Kill them.

  	 */
  	ip_ra_control(sk, 0, NULL);
  
  	sk_common_release(sk);
  }

  static void raw_destroy(struct sock *sk)

  {
  	lock_sock(sk);
  	ip_flush_pending_frames(sk);
  	release_sock(sk);

  }

  /* This gets rid of all the nasties in af_inet. -DaveM */
  static int raw_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
  {
  	struct inet_sock *inet = inet_sk(sk);
  	struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
  	int ret = -EINVAL;
  	int chk_addr_ret;
  
  	if (sk->sk_state != TCP_CLOSE || addr_len < sizeof(struct sockaddr_in))
  		goto out;

  	chk_addr_ret = inet_addr_type(sock_net(sk), addr->sin_addr.s_addr);

  	ret = -EADDRNOTAVAIL;
  	if (addr->sin_addr.s_addr && chk_addr_ret != RTN_LOCAL &&
  	    chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST)
  		goto out;

  	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;

  	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)

  		inet->inet_saddr = 0;  /* Use device */

  	sk_dst_reset(sk);
  	ret = 0;
  out:	return ret;
  }
  
  /*
   *	This should be easy, if there is something there
   *	we return it, otherwise we block.
   */

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

  {
  	struct inet_sock *inet = inet_sk(sk);
  	size_t copied = 0;
  	int err = -EOPNOTSUPP;

  	DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);

  	struct sk_buff *skb;
  
  	if (flags & MSG_OOB)
  		goto out;

  	if (flags & MSG_ERRQUEUE) {

  		err = ip_recv_error(sk, msg, len, addr_len);

  		goto out;
  	}
  
  	skb = skb_recv_datagram(sk, flags, noblock, &err);
  	if (!skb)
  		goto out;
  
  	copied = skb->len;
  	if (len < copied) {
  		msg->msg_flags |= MSG_TRUNC;
  		copied = len;
  	}

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

  	if (err)
  		goto done;

  	sock_recv_ts_and_drops(msg, sk, skb);

  
  	/* Copy the address. */
  	if (sin) {
  		sin->sin_family = AF_INET;

  		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;

  		sin->sin_port = 0;

  		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));

  		*addr_len = sizeof(*sin);

  	}
  	if (inet->cmsg_flags)
  		ip_cmsg_recv(msg, skb);
  	if (flags & MSG_TRUNC)
  		copied = skb->len;
  done:
  	skb_free_datagram(sk, skb);

  out:
  	if (err)
  		return err;
  	return copied;

  }
  
  static int raw_init(struct sock *sk)
  {
  	struct raw_sock *rp = raw_sk(sk);

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

  		memset(&rp->filter, 0, sizeof(rp->filter));
  	return 0;
  }
  
  static int raw_seticmpfilter(struct sock *sk, char __user *optval, int optlen)
  {
  	if (optlen > sizeof(struct icmp_filter))
  		optlen = sizeof(struct icmp_filter);
  	if (copy_from_user(&raw_sk(sk)->filter, optval, optlen))
  		return -EFAULT;
  	return 0;
  }
  
  static int raw_geticmpfilter(struct sock *sk, char __user *optval, int __user *optlen)
  {
  	int len, ret = -EFAULT;
  
  	if (get_user(len, optlen))
  		goto out;
  	ret = -EINVAL;
  	if (len < 0)
  		goto out;
  	if (len > sizeof(struct icmp_filter))
  		len = sizeof(struct icmp_filter);
  	ret = -EFAULT;
  	if (put_user(len, optlen) ||
  	    copy_to_user(optval, &raw_sk(sk)->filter, len))
  		goto out;
  	ret = 0;
  out:	return ret;
  }

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

  			  char __user *optval, unsigned int optlen)

  {

  	if (optname == ICMP_FILTER) {

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

  			return -EOPNOTSUPP;
  		else
  			return raw_seticmpfilter(sk, optval, optlen);
  	}
  	return -ENOPROTOOPT;
  }

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

  			  char __user *optval, unsigned int optlen)

  {
  	if (level != SOL_RAW)

  		return ip_setsockopt(sk, level, optname, optval, optlen);
  	return do_raw_setsockopt(sk, level, optname, optval, optlen);
  }

  #ifdef CONFIG_COMPAT
  static int compat_raw_setsockopt(struct sock *sk, int level, int optname,

  				 char __user *optval, unsigned int optlen)

  {
  	if (level != SOL_RAW)

  		return compat_ip_setsockopt(sk, level, optname, optval, optlen);

  	return do_raw_setsockopt(sk, level, optname, optval, optlen);
  }
  #endif
  
  static int do_raw_getsockopt(struct sock *sk, int level, int optname,
  			  char __user *optval, int __user *optlen)
  {

  	if (optname == ICMP_FILTER) {

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

  			return -EOPNOTSUPP;
  		else
  			return raw_geticmpfilter(sk, optval, optlen);
  	}
  	return -ENOPROTOOPT;
  }

  static int raw_getsockopt(struct sock *sk, int level, int optname,
  			  char __user *optval, int __user *optlen)
  {
  	if (level != SOL_RAW)
  		return ip_getsockopt(sk, level, optname, optval, optlen);
  	return do_raw_getsockopt(sk, level, optname, optval, optlen);
  }
  
  #ifdef CONFIG_COMPAT
  static int compat_raw_getsockopt(struct sock *sk, int level, int optname,

  				 char __user *optval, int __user *optlen)

  {
  	if (level != SOL_RAW)

  		return compat_ip_getsockopt(sk, level, optname, optval, optlen);

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

  static int raw_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_IP_MROUTE

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

  #else

  		return -ENOIOCTLCMD;

  #endif
  	}
  }

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

  struct proto raw_prot = {

  	.name		   = "RAW",
  	.owner		   = THIS_MODULE,
  	.close		   = raw_close,

  	.destroy	   = raw_destroy,

  	.connect	   = ip4_datagram_connect,

  	.disconnect	   = __udp_disconnect,

  	.ioctl		   = raw_ioctl,
  	.init		   = raw_init,
  	.setsockopt	   = raw_setsockopt,
  	.getsockopt	   = raw_getsockopt,
  	.sendmsg	   = raw_sendmsg,
  	.recvmsg	   = raw_recvmsg,
  	.bind		   = raw_bind,
  	.backlog_rcv	   = raw_rcv_skb,

  	.release_cb	   = ip4_datagram_release_cb,

  	.hash		   = raw_hash_sk,
  	.unhash		   = raw_unhash_sk,

  	.obj_size	   = sizeof(struct raw_sock),

  	.h.raw_hash	   = &raw_v4_hashinfo,

  #ifdef CONFIG_COMPAT

  	.compat_setsockopt = compat_raw_setsockopt,
  	.compat_getsockopt = compat_raw_getsockopt,

  	.compat_ioctl	   = compat_raw_ioctl,

  #endif

  };
  
  #ifdef CONFIG_PROC_FS

  static struct sock *raw_get_first(struct seq_file *seq)
  {
  	struct sock *sk;

  	struct raw_iter_state *state = raw_seq_private(seq);

  	for (state->bucket = 0; state->bucket < RAW_HTABLE_SIZE;
  			++state->bucket) {

  		sk_for_each(sk, &state->h->ht[state->bucket])

  			if (sock_net(sk) == seq_file_net(seq))

  				goto found;
  	}
  	sk = NULL;
  found:
  	return sk;
  }
  
  static struct sock *raw_get_next(struct seq_file *seq, struct sock *sk)
  {

  	struct raw_iter_state *state = raw_seq_private(seq);

  
  	do {
  		sk = sk_next(sk);
  try_again:
  		;

  	} while (sk && sock_net(sk) != seq_file_net(seq));

  	if (!sk && ++state->bucket < RAW_HTABLE_SIZE) {

  		sk = sk_head(&state->h->ht[state->bucket]);

  		goto try_again;
  	}
  	return sk;
  }
  
  static struct sock *raw_get_idx(struct seq_file *seq, loff_t pos)
  {
  	struct sock *sk = raw_get_first(seq);
  
  	if (sk)
  		while (pos && (sk = raw_get_next(seq, sk)) != NULL)
  			--pos;
  	return pos ? NULL : sk;
  }

  void *raw_seq_start(struct seq_file *seq, loff_t *pos)

  {

  	struct raw_iter_state *state = raw_seq_private(seq);
  
  	read_lock(&state->h->lock);

  	return *pos ? raw_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
  }

  EXPORT_SYMBOL_GPL(raw_seq_start);

  void *raw_seq_next(struct seq_file *seq, void *v, loff_t *pos)

  {
  	struct sock *sk;
  
  	if (v == SEQ_START_TOKEN)
  		sk = raw_get_first(seq);
  	else
  		sk = raw_get_next(seq, v);
  	++*pos;
  	return sk;
  }

  EXPORT_SYMBOL_GPL(raw_seq_next);

  void raw_seq_stop(struct seq_file *seq, void *v)

  {

  	struct raw_iter_state *state = raw_seq_private(seq);
  
  	read_unlock(&state->h->lock);

  }

  EXPORT_SYMBOL_GPL(raw_seq_stop);

  static void raw_sock_seq_show(struct seq_file *seq, struct sock *sp, int i)

  {
  	struct inet_sock *inet = inet_sk(sp);

  	__be32 dest = inet->inet_daddr,
  	       src = inet->inet_rcv_saddr;

  	__u16 destp = 0,

  	      srcp  = inet->inet_num;

  	seq_printf(seq, "%4d: %08X:%04X %08X:%04X"

  		" %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d
  ",

  		i, src, srcp, dest, destp, sp->sk_state,

  		sk_wmem_alloc_get(sp),
  		sk_rmem_alloc_get(sp),

  		0, 0L, 0,
  		from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
  		0, sock_i_ino(sp),

  		atomic_read(&sp->sk_refcnt), sp, atomic_read(&sp->sk_drops));

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

  	if (v == SEQ_START_TOKEN)

  		seq_printf(seq, "  sl  local_address rem_address   st tx_queue "
  				"rx_queue tr tm->when retrnsmt   uid  timeout "

  				"inode ref pointer drops
  ");

  	else
  		raw_sock_seq_show(seq, v, raw_seq_private(seq)->bucket);

  	return 0;
  }

  static const struct seq_operations raw_seq_ops = {

  	.start = raw_seq_start,
  	.next  = raw_seq_next,
  	.stop  = raw_seq_stop,
  	.show  = raw_seq_show,
  };

  int raw_seq_open(struct inode *ino, struct file *file,
  		 struct raw_hashinfo *h, const struct seq_operations *ops)

  {

  	int err;

  	struct raw_iter_state *i;

  	err = seq_open_net(ino, file, ops, sizeof(struct raw_iter_state));

  	if (err < 0)
  		return err;

  	i = raw_seq_private((struct seq_file *)file->private_data);

  	i->h = h;

  	return 0;
  }
  EXPORT_SYMBOL_GPL(raw_seq_open);
  
  static int raw_v4_seq_open(struct inode *inode, struct file *file)
  {

  	return raw_seq_open(inode, file, &raw_v4_hashinfo, &raw_seq_ops);

  }

  static const struct file_operations raw_seq_fops = {

  	.owner	 = THIS_MODULE,

  	.open	 = raw_v4_seq_open,

  	.read	 = seq_read,
  	.llseek	 = seq_lseek,

  	.release = seq_release_net,

  };

  static __net_init int raw_init_net(struct net *net)

  {

  	if (!proc_create("raw", S_IRUGO, net->proc_net, &raw_seq_fops))

  		return -ENOMEM;

  	return 0;
  }

  static __net_exit void raw_exit_net(struct net *net)
  {

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

  }
  
  static __net_initdata struct pernet_operations raw_net_ops = {
  	.init = raw_init_net,
  	.exit = raw_exit_net,
  };
  
  int __init raw_proc_init(void)
  {
  	return register_pernet_subsys(&raw_net_ops);
  }

  void __init raw_proc_exit(void)
  {

  	unregister_pernet_subsys(&raw_net_ops);

  }
  #endif /* CONFIG_PROC_FS */