/*
   * Raw IEEE 802.15.4 sockets
   *
   * Copyright 2007, 2008 Siemens AG
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2
   * as published by the Free Software Foundation.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License along
   * with this program; if not, write to the Free Software Foundation, Inc.,
   * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Written by:
   * Sergey Lapin <slapin@ossfans.org>
   * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
   */
  
  #include <linux/net.h>
  #include <linux/module.h>
  #include <linux/if_arp.h>
  #include <linux/list.h>

  #include <linux/slab.h>

  #include <net/sock.h>

  #include <net/af_ieee802154.h>

  
  #include "af802154.h"
  
  static HLIST_HEAD(raw_head);
  static DEFINE_RWLOCK(raw_lock);
  
  static void raw_hash(struct sock *sk)
  {
  	write_lock_bh(&raw_lock);
  	sk_add_node(sk, &raw_head);
  	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
  	write_unlock_bh(&raw_lock);
  }
  
  static void raw_unhash(struct sock *sk)
  {
  	write_lock_bh(&raw_lock);
  	if (sk_del_node_init(sk))
  		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
  	write_unlock_bh(&raw_lock);
  }
  
  static void raw_close(struct sock *sk, long timeout)
  {
  	sk_common_release(sk);
  }
  
  static int raw_bind(struct sock *sk, struct sockaddr *uaddr, int len)
  {
  	struct sockaddr_ieee802154 *addr = (struct sockaddr_ieee802154 *)uaddr;
  	int err = 0;
  	struct net_device *dev = NULL;
  
  	if (len < sizeof(*addr))
  		return -EINVAL;
  
  	if (addr->family != AF_IEEE802154)
  		return -EINVAL;
  
  	lock_sock(sk);
  
  	dev = ieee802154_get_dev(sock_net(sk), &addr->addr);
  	if (!dev) {
  		err = -ENODEV;
  		goto out;
  	}

  	if (dev->type != ARPHRD_IEEE802154) {

  		err = -ENODEV;
  		goto out_put;
  	}
  
  	sk->sk_bound_dev_if = dev->ifindex;
  	sk_dst_reset(sk);
  
  out_put:
  	dev_put(dev);
  out:
  	release_sock(sk);
  
  	return err;
  }
  
  static int raw_connect(struct sock *sk, struct sockaddr *uaddr,
  			int addr_len)
  {
  	return -ENOTSUPP;
  }
  
  static int raw_disconnect(struct sock *sk, int flags)
  {
  	return 0;
  }
  
  static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
  		       size_t size)
  {
  	struct net_device *dev;

  	unsigned int mtu;

  	struct sk_buff *skb;

  	int hlen, tlen;

  	int err;
  
  	if (msg->msg_flags & MSG_OOB) {
  		pr_debug("msg->msg_flags = 0x%x
  ", msg->msg_flags);
  		return -EOPNOTSUPP;
  	}
  
  	lock_sock(sk);
  	if (!sk->sk_bound_dev_if)
  		dev = dev_getfirstbyhwtype(sock_net(sk), ARPHRD_IEEE802154);
  	else
  		dev = dev_get_by_index(sock_net(sk), sk->sk_bound_dev_if);
  	release_sock(sk);
  
  	if (!dev) {
  		pr_debug("no dev
  ");
  		err = -ENXIO;
  		goto out;
  	}
  
  	mtu = dev->mtu;
  	pr_debug("name = %s, mtu = %u
  ", dev->name, mtu);
  
  	if (size > mtu) {

  		pr_debug("size = %Zu, mtu = %u
  ", size, mtu);

  		err = -EINVAL;
  		goto out_dev;
  	}

  	hlen = LL_RESERVED_SPACE(dev);
  	tlen = dev->needed_tailroom;
  	skb = sock_alloc_send_skb(sk, hlen + tlen + size,

  			msg->msg_flags & MSG_DONTWAIT, &err);
  	if (!skb)
  		goto out_dev;

  	skb_reserve(skb, hlen);

  
  	skb_reset_mac_header(skb);
  	skb_reset_network_header(skb);
  
  	err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
  	if (err < 0)
  		goto out_skb;
  
  	skb->dev = dev;
  	skb->sk  = sk;
  	skb->protocol = htons(ETH_P_IEEE802154);
  
  	dev_put(dev);
  
  	err = dev_queue_xmit(skb);
  	if (err > 0)
  		err = net_xmit_errno(err);
  
  	return err ?: size;
  
  out_skb:
  	kfree_skb(skb);
  out_dev:
  	dev_put(dev);
  out:
  	return err;
  }
  
  static int raw_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
  		       size_t len, int noblock, int flags, int *addr_len)
  {
  	size_t copied = 0;
  	int err = -EOPNOTSUPP;
  	struct sk_buff *skb;
  
  	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_iovec(skb, 0, msg->msg_iov, copied);
  	if (err)
  		goto done;

  	sock_recv_ts_and_drops(msg, sk, skb);

  
  	if (flags & MSG_TRUNC)
  		copied = skb->len;
  done:
  	skb_free_datagram(sk, skb);
  out:
  	if (err)
  		return err;
  	return copied;
  }
  
  static int raw_rcv_skb(struct sock *sk, struct sk_buff *skb)
  {
  	if (sock_queue_rcv_skb(sk, skb) < 0) {

  		kfree_skb(skb);
  		return NET_RX_DROP;
  	}
  
  	return NET_RX_SUCCESS;
  }
  
  
  void ieee802154_raw_deliver(struct net_device *dev, struct sk_buff *skb)
  {
  	struct sock *sk;

  
  	read_lock(&raw_lock);

  	sk_for_each(sk, &raw_head) {

  		bh_lock_sock(sk);
  		if (!sk->sk_bound_dev_if ||
  		    sk->sk_bound_dev_if == dev->ifindex) {
  
  			struct sk_buff *clone;
  
  			clone = skb_clone(skb, GFP_ATOMIC);
  			if (clone)
  				raw_rcv_skb(sk, clone);
  		}
  		bh_unlock_sock(sk);
  	}
  	read_unlock(&raw_lock);
  }

  static int raw_getsockopt(struct sock *sk, int level, int optname,
  		    char __user *optval, int __user *optlen)
  {
  	return -EOPNOTSUPP;
  }
  
  static int raw_setsockopt(struct sock *sk, int level, int optname,

  		    char __user *optval, unsigned int optlen)

  {
  	return -EOPNOTSUPP;
  }

  struct proto ieee802154_raw_prot = {
  	.name		= "IEEE-802.15.4-RAW",
  	.owner		= THIS_MODULE,
  	.obj_size	= sizeof(struct sock),
  	.close		= raw_close,
  	.bind		= raw_bind,
  	.sendmsg	= raw_sendmsg,
  	.recvmsg	= raw_recvmsg,
  	.hash		= raw_hash,
  	.unhash		= raw_unhash,
  	.connect	= raw_connect,
  	.disconnect	= raw_disconnect,

  	.getsockopt	= raw_getsockopt,
  	.setsockopt	= raw_setsockopt,

  };