/*
   *  UDPLITE     An implementation of the UDP-Lite protocol (RFC 3828).
   *

   *  Authors:    Gerrit Renker       <gerrit@erg.abdn.ac.uk>
   *
   *  Changes:
   *  Fixes:
   *		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.
   */

  
  #define pr_fmt(fmt) "UDPLite: " fmt

  #include <linux/export.h>

  #include "udp_impl.h"

  struct udp_table 	udplite_table __read_mostly;

  EXPORT_SYMBOL(udplite_table);

  static int udplite_rcv(struct sk_buff *skb)

  {

  	return __udp4_lib_rcv(skb, &udplite_table, IPPROTO_UDPLITE);

  }

  static void udplite_err(struct sk_buff *skb, u32 info)

  {

  	__udp4_lib_err(skb, info, &udplite_table);

  }

  static const struct net_protocol udplite_protocol = {

  	.handler	= udplite_rcv,
  	.err_handler	= udplite_err,
  	.no_policy	= 1,

  	.netns_ok	= 1,

  };
  
  struct proto 	udplite_prot = {
  	.name		   = "UDP-Lite",
  	.owner		   = THIS_MODULE,
  	.close		   = udp_lib_close,
  	.connect	   = ip4_datagram_connect,
  	.disconnect	   = udp_disconnect,
  	.ioctl		   = udp_ioctl,
  	.init		   = udplite_sk_init,
  	.destroy	   = udp_destroy_sock,
  	.setsockopt	   = udp_setsockopt,
  	.getsockopt	   = udp_getsockopt,
  	.sendmsg	   = udp_sendmsg,
  	.recvmsg	   = udp_recvmsg,
  	.sendpage	   = udp_sendpage,
  	.backlog_rcv	   = udp_queue_rcv_skb,
  	.hash		   = udp_lib_hash,
  	.unhash		   = udp_lib_unhash,

  	.get_port	   = udp_v4_get_port,

  	.obj_size	   = sizeof(struct udp_sock),

  	.slab_flags	   = SLAB_DESTROY_BY_RCU,

  	.h.udp_table	   = &udplite_table,

  #ifdef CONFIG_COMPAT
  	.compat_setsockopt = compat_udp_setsockopt,
  	.compat_getsockopt = compat_udp_getsockopt,
  #endif

  	.clear_sk	   = sk_prot_clear_portaddr_nulls,

  };

  EXPORT_SYMBOL(udplite_prot);

  
  static struct inet_protosw udplite4_protosw = {
  	.type		=  SOCK_DGRAM,
  	.protocol	=  IPPROTO_UDPLITE,
  	.prot		=  &udplite_prot,
  	.ops		=  &inet_dgram_ops,

  	.no_check	=  0,		/* must checksum (RFC 3828) */
  	.flags		=  INET_PROTOSW_PERMANENT,
  };
  
  #ifdef CONFIG_PROC_FS

  
  static const struct file_operations udplite_afinfo_seq_fops = {
  	.owner    = THIS_MODULE,
  	.open     = udp_seq_open,
  	.read     = seq_read,
  	.llseek   = seq_lseek,
  	.release  = seq_release_net
  };

  static struct udp_seq_afinfo udplite4_seq_afinfo = {

  	.name		= "udplite",
  	.family		= AF_INET,

  	.udp_table 	= &udplite_table,

  	.seq_fops	= &udplite_afinfo_seq_fops,

  	.seq_ops	= {
  		.show		= udp4_seq_show,
  	},

  };

  static int __net_init udplite4_proc_init_net(struct net *net)

  {
  	return udp_proc_register(net, &udplite4_seq_afinfo);
  }

  static void __net_exit udplite4_proc_exit_net(struct net *net)

  {
  	udp_proc_unregister(net, &udplite4_seq_afinfo);
  }
  
  static struct pernet_operations udplite4_net_ops = {
  	.init = udplite4_proc_init_net,
  	.exit = udplite4_proc_exit_net,
  };

  static __init int udplite4_proc_init(void)
  {

  	return register_pernet_subsys(&udplite4_net_ops);

  }
  #else
  static inline int udplite4_proc_init(void)
  {
  	return 0;
  }

  #endif
  
  void __init udplite4_register(void)
  {

  	udp_table_init(&udplite_table, "UDP-Lite");

  	if (proto_register(&udplite_prot, 1))
  		goto out_register_err;
  
  	if (inet_add_protocol(&udplite_protocol, IPPROTO_UDPLITE) < 0)
  		goto out_unregister_proto;
  
  	inet_register_protosw(&udplite4_protosw);

  	if (udplite4_proc_init())

  		pr_err("%s: Cannot register /proc!
  ", __func__);

  	return;
  
  out_unregister_proto:
  	proto_unregister(&udplite_prot);
  out_register_err:

  	pr_crit("%s: Cannot add UDP-Lite protocol
  ", __func__);

  }