/* SCTP kernel reference Implementation
   * (C) Copyright IBM Corp. 2001, 2004
   * Copyright (c) 1999-2000 Cisco, Inc.
   * Copyright (c) 1999-2001 Motorola, Inc.
   * Copyright (c) 2001 Intel Corp.
   * Copyright (c) 2001 Nokia, Inc.
   * Copyright (c) 2001 La Monte H.P. Yarroll
   *
   * This file is part of the SCTP kernel reference Implementation
   *
   * Initialization/cleanup for SCTP protocol support.
   *
   * The SCTP reference implementation 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, or (at your option)
   * any later version.
   *
   * The SCTP reference implementation 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 GNU CC; see the file COPYING.  If not, write to
   * the Free Software Foundation, 59 Temple Place - Suite 330,
   * Boston, MA 02111-1307, USA.
   *
   * Please send any bug reports or fixes you make to the
   * email address(es):
   *    lksctp developers <lksctp-developers@lists.sourceforge.net>
   *
   * Or submit a bug report through the following website:
   *    http://www.sf.net/projects/lksctp
   *
   * Written or modified by:
   *    La Monte H.P. Yarroll <piggy@acm.org>
   *    Karl Knutson <karl@athena.chicago.il.us>
   *    Jon Grimm <jgrimm@us.ibm.com>
   *    Sridhar Samudrala <sri@us.ibm.com>
   *    Daisy Chang <daisyc@us.ibm.com>
   *    Ardelle Fan <ardelle.fan@intel.com>
   *
   * Any bugs reported given to us we will try to fix... any fixes shared will
   * be incorporated into the next SCTP release.
   */
  
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/netdevice.h>
  #include <linux/inetdevice.h>
  #include <linux/seq_file.h>
  #include <net/protocol.h>
  #include <net/ip.h>
  #include <net/ipv6.h>

  #include <net/route.h>

  #include <net/sctp/sctp.h>
  #include <net/addrconf.h>
  #include <net/inet_common.h>
  #include <net/inet_ecn.h>
  
  /* Global data structures. */

  struct sctp_globals sctp_globals __read_mostly;

  struct proc_dir_entry	*proc_net_sctp;

  DEFINE_SNMP_STAT(struct sctp_mib, sctp_statistics) __read_mostly;

  
  struct idr sctp_assocs_id;
  DEFINE_SPINLOCK(sctp_assocs_id_lock);
  
  /* This is the global socket data structure used for responding to
   * the Out-of-the-blue (OOTB) packets.  A control sock will be created
   * for this socket at the initialization time.
   */
  static struct socket *sctp_ctl_socket;
  
  static struct sctp_pf *sctp_pf_inet6_specific;
  static struct sctp_pf *sctp_pf_inet_specific;
  static struct sctp_af *sctp_af_v4_specific;
  static struct sctp_af *sctp_af_v6_specific;

  struct kmem_cache *sctp_chunk_cachep __read_mostly;
  struct kmem_cache *sctp_bucket_cachep __read_mostly;

  /* Return the address of the control sock. */
  struct sock *sctp_get_ctl_sock(void)
  {
  	return sctp_ctl_socket->sk;
  }
  
  /* Set up the proc fs entry for the SCTP protocol. */
  static __init int sctp_proc_init(void)
  {
  	if (!proc_net_sctp) {
  		struct proc_dir_entry *ent;
  		ent = proc_mkdir("net/sctp", NULL);
  		if (ent) {
  			ent->owner = THIS_MODULE;
  			proc_net_sctp = ent;
  		} else
  			goto out_nomem;
  	}
  
  	if (sctp_snmp_proc_init())

  		goto out_nomem;

  	if (sctp_eps_proc_init())

  		goto out_nomem;

  	if (sctp_assocs_proc_init())

  		goto out_nomem;

  
  	return 0;
  
  out_nomem:
  	return -ENOMEM;
  }

  /* Clean up the proc fs entry for the SCTP protocol.

   * Note: Do not make this __exit as it is used in the init error
   * path.
   */
  static void sctp_proc_exit(void)
  {
  	sctp_snmp_proc_exit();
  	sctp_eps_proc_exit();
  	sctp_assocs_proc_exit();
  
  	if (proc_net_sctp) {
  		proc_net_sctp = NULL;
  		remove_proc_entry("net/sctp", NULL);
  	}
  }
  
  /* Private helper to extract ipv4 address and stash them in
   * the protocol structure.
   */
  static void sctp_v4_copy_addrlist(struct list_head *addrlist,
  				  struct net_device *dev)
  {
  	struct in_device *in_dev;
  	struct in_ifaddr *ifa;
  	struct sctp_sockaddr_entry *addr;
  
  	rcu_read_lock();

  	if ((in_dev = __in_dev_get_rcu(dev)) == NULL) {

  		rcu_read_unlock();
  		return;
  	}
  
  	for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
  		/* Add the address to the local list.  */
  		addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
  		if (addr) {

  			addr->a.v4.sin_family = AF_INET;
  			addr->a.v4.sin_port = 0;
  			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;

  			list_add_tail(&addr->list, addrlist);
  		}
  	}
  
  	rcu_read_unlock();
  }
  
  /* Extract our IP addresses from the system and stash them in the
   * protocol structure.
   */

  static void sctp_get_local_addr_list(void)

  {
  	struct net_device *dev;
  	struct list_head *pos;
  	struct sctp_af *af;
  
  	read_lock(&dev_base_lock);

  	for_each_netdev(dev) {

  		__list_for_each(pos, &sctp_address_families) {
  			af = list_entry(pos, struct sctp_af, list);
  			af->copy_addrlist(&sctp_local_addr_list, dev);
  		}
  	}
  	read_unlock(&dev_base_lock);
  }

  /* Free the existing local addresses.  */

  static void sctp_free_local_addr_list(void)

  {
  	struct sctp_sockaddr_entry *addr;
  	struct list_head *pos, *temp;
  
  	list_for_each_safe(pos, temp, &sctp_local_addr_list) {
  		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
  		list_del(pos);
  		kfree(addr);
  	}
  }

  /* Copy the local addresses which are valid for 'scope' into 'bp'.  */
  int sctp_copy_local_addr_list(struct sctp_bind_addr *bp, sctp_scope_t scope,

  			      gfp_t gfp, int copy_flags)

  {
  	struct sctp_sockaddr_entry *addr;
  	int error = 0;

  	struct list_head *pos, *temp;

  	list_for_each_safe(pos, temp, &sctp_local_addr_list) {

  		addr = list_entry(pos, struct sctp_sockaddr_entry, list);

  		if (sctp_in_scope(&addr->a, scope)) {

  			/* Now that the address is in scope, check to see if
  			 * the address type is really supported by the local
  			 * sock as well as the remote peer.
  			 */

  			if ((((AF_INET == addr->a.sa.sa_family) &&

  			      (copy_flags & SCTP_ADDR4_PEERSUPP))) ||

  			    (((AF_INET6 == addr->a.sa.sa_family) &&

  			      (copy_flags & SCTP_ADDR6_ALLOWED) &&
  			      (copy_flags & SCTP_ADDR6_PEERSUPP)))) {

  				error = sctp_add_bind_addr(bp, &addr->a, 1,

  							   GFP_ATOMIC);
  				if (error)
  					goto end_copy;
  			}
  		}
  	}
  
  end_copy:

  	return error;
  }
  
  /* Initialize a sctp_addr from in incoming skb.  */
  static void sctp_v4_from_skb(union sctp_addr *addr, struct sk_buff *skb,
  			     int is_saddr)
  {
  	void *from;

  	__be16 *port;

  	struct sctphdr *sh;
  
  	port = &addr->v4.sin_port;
  	addr->v4.sin_family = AF_INET;

  	sh = sctp_hdr(skb);

  	if (is_saddr) {

  		*port  = sh->source;

  		from = &ip_hdr(skb)->saddr;

  	} else {

  		*port = sh->dest;

  		from = &ip_hdr(skb)->daddr;

  	}
  	memcpy(&addr->v4.sin_addr.s_addr, from, sizeof(struct in_addr));
  }
  
  /* Initialize an sctp_addr from a socket. */
  static void sctp_v4_from_sk(union sctp_addr *addr, struct sock *sk)
  {
  	addr->v4.sin_family = AF_INET;

  	addr->v4.sin_port = 0;

  	addr->v4.sin_addr.s_addr = inet_sk(sk)->rcv_saddr;
  }
  
  /* Initialize sk->sk_rcv_saddr from sctp_addr. */
  static void sctp_v4_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
  {
  	inet_sk(sk)->rcv_saddr = addr->v4.sin_addr.s_addr;
  }
  
  /* Initialize sk->sk_daddr from sctp_addr. */
  static void sctp_v4_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
  {
  	inet_sk(sk)->daddr = addr->v4.sin_addr.s_addr;
  }
  
  /* Initialize a sctp_addr from an address parameter. */
  static void sctp_v4_from_addr_param(union sctp_addr *addr,
  				    union sctp_addr_param *param,

  				    __be16 port, int iif)

  {
  	addr->v4.sin_family = AF_INET;
  	addr->v4.sin_port = port;
  	addr->v4.sin_addr.s_addr = param->v4.addr.s_addr;
  }
  
  /* Initialize an address parameter from a sctp_addr and return the length
   * of the address parameter.
   */
  static int sctp_v4_to_addr_param(const union sctp_addr *addr,
  				 union sctp_addr_param *param)
  {
  	int length = sizeof(sctp_ipv4addr_param_t);
  
  	param->v4.param_hdr.type = SCTP_PARAM_IPV4_ADDRESS;

  	param->v4.param_hdr.length = htons(length);

  	param->v4.addr.s_addr = addr->v4.sin_addr.s_addr;

  
  	return length;
  }
  
  /* Initialize a sctp_addr from a dst_entry. */
  static void sctp_v4_dst_saddr(union sctp_addr *saddr, struct dst_entry *dst,

  			      __be16 port)

  {
  	struct rtable *rt = (struct rtable *)dst;
  	saddr->v4.sin_family = AF_INET;
  	saddr->v4.sin_port = port;
  	saddr->v4.sin_addr.s_addr = rt->rt_src;
  }
  
  /* Compare two addresses exactly. */
  static int sctp_v4_cmp_addr(const union sctp_addr *addr1,
  			    const union sctp_addr *addr2)
  {
  	if (addr1->sa.sa_family != addr2->sa.sa_family)
  		return 0;
  	if (addr1->v4.sin_port != addr2->v4.sin_port)
  		return 0;
  	if (addr1->v4.sin_addr.s_addr != addr2->v4.sin_addr.s_addr)
  		return 0;
  
  	return 1;
  }
  
  /* Initialize addr struct to INADDR_ANY. */

  static void sctp_v4_inaddr_any(union sctp_addr *addr, __be16 port)

  {
  	addr->v4.sin_family = AF_INET;
  	addr->v4.sin_addr.s_addr = INADDR_ANY;
  	addr->v4.sin_port = port;
  }
  
  /* Is this a wildcard address? */
  static int sctp_v4_is_any(const union sctp_addr *addr)
  {
  	return INADDR_ANY == addr->v4.sin_addr.s_addr;
  }
  
  /* This function checks if the address is a valid address to be used for
   * SCTP binding.
   *
   * Output:
   * Return 0 - If the address is a non-unicast or an illegal address.
   * Return 1 - If the address is a unicast.
   */

  static int sctp_v4_addr_valid(union sctp_addr *addr,
  			      struct sctp_sock *sp,
  			      const struct sk_buff *skb)

  {
  	/* Is this a non-unicast address or a unusable SCTP address? */
  	if (IS_IPV4_UNUSABLE_ADDRESS(&addr->v4.sin_addr.s_addr))
  		return 0;

  	/* Is this a broadcast address? */
  	if (skb && ((struct rtable *)skb->dst)->rt_flags & RTCF_BROADCAST)
  		return 0;

  	return 1;
  }
  
  /* Should this be available for binding?   */
  static int sctp_v4_available(union sctp_addr *addr, struct sctp_sock *sp)
  {
  	int ret = inet_addr_type(addr->v4.sin_addr.s_addr);

  	if (addr->v4.sin_addr.s_addr != INADDR_ANY &&
  	   ret != RTN_LOCAL &&
  	   !sp->inet.freebind &&
  	   !sysctl_ip_nonlocal_bind)

  		return 0;

  	return 1;
  }
  
  /* Checking the loopback, private and other address scopes as defined in
   * RFC 1918.   The IPv4 scoping is based on the draft for SCTP IPv4
   * scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
   *
   * Level 0 - unusable SCTP addresses
   * Level 1 - loopback address
   * Level 2 - link-local addresses
   * Level 3 - private addresses.
   * Level 4 - global addresses
   * For INIT and INIT-ACK address list, let L be the level of
   * of requested destination address, sender and receiver
   * SHOULD include all of its addresses with level greater
   * than or equal to L.
   */
  static sctp_scope_t sctp_v4_scope(union sctp_addr *addr)
  {
  	sctp_scope_t retval;
  
  	/* Should IPv4 scoping be a sysctl configurable option
  	 * so users can turn it off (default on) for certain
  	 * unconventional networking environments?
  	 */
  
  	/* Check for unusable SCTP addresses. */
  	if (IS_IPV4_UNUSABLE_ADDRESS(&addr->v4.sin_addr.s_addr)) {
  		retval =  SCTP_SCOPE_UNUSABLE;
  	} else if (LOOPBACK(addr->v4.sin_addr.s_addr)) {
  		retval = SCTP_SCOPE_LOOPBACK;
  	} else if (IS_IPV4_LINK_ADDRESS(&addr->v4.sin_addr.s_addr)) {
  		retval = SCTP_SCOPE_LINK;
  	} else if (IS_IPV4_PRIVATE_ADDRESS(&addr->v4.sin_addr.s_addr)) {
  		retval = SCTP_SCOPE_PRIVATE;
  	} else {
  		retval = SCTP_SCOPE_GLOBAL;
  	}
  
  	return retval;
  }
  
  /* Returns a valid dst cache entry for the given source and destination ip
   * addresses. If an association is passed, trys to get a dst entry with a
   * source address that matches an address in the bind address list.
   */
  static struct dst_entry *sctp_v4_get_dst(struct sctp_association *asoc,
  					 union sctp_addr *daddr,
  					 union sctp_addr *saddr)
  {
  	struct rtable *rt;
  	struct flowi fl;
  	struct sctp_bind_addr *bp;
  	rwlock_t *addr_lock;
  	struct sctp_sockaddr_entry *laddr;
  	struct list_head *pos;
  	struct dst_entry *dst = NULL;
  	union sctp_addr dst_saddr;
  
  	memset(&fl, 0x0, sizeof(struct flowi));
  	fl.fl4_dst  = daddr->v4.sin_addr.s_addr;
  	fl.proto = IPPROTO_SCTP;
  	if (asoc) {
  		fl.fl4_tos = RT_CONN_FLAGS(asoc->base.sk);
  		fl.oif = asoc->base.sk->sk_bound_dev_if;
  	}
  	if (saddr)
  		fl.fl4_src = saddr->v4.sin_addr.s_addr;
  
  	SCTP_DEBUG_PRINTK("%s: DST:%u.%u.%u.%u, SRC:%u.%u.%u.%u - ",
  			  __FUNCTION__, NIPQUAD(fl.fl4_dst),
  			  NIPQUAD(fl.fl4_src));
  
  	if (!ip_route_output_key(&rt, &fl)) {
  		dst = &rt->u.dst;
  	}
  
  	/* If there is no association or if a source address is passed, no
  	 * more validation is required.
  	 */
  	if (!asoc || saddr)
  		goto out;
  
  	bp = &asoc->base.bind_addr;
  	addr_lock = &asoc->base.addr_lock;
  
  	if (dst) {
  		/* Walk through the bind address list and look for a bind
  		 * address that matches the source address of the returned dst.
  		 */
  		sctp_read_lock(addr_lock);
  		list_for_each(pos, &bp->address_list) {
  			laddr = list_entry(pos, struct sctp_sockaddr_entry,
  					   list);

  			if (!laddr->use_as_src)
  				continue;

  			sctp_v4_dst_saddr(&dst_saddr, dst, htons(bp->port));
  			if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a))

  				goto out_unlock;
  		}
  		sctp_read_unlock(addr_lock);
  
  		/* None of the bound addresses match the source address of the
  		 * dst. So release it.
  		 */
  		dst_release(dst);
  		dst = NULL;
  	}
  
  	/* Walk through the bind address list and try to get a dst that
  	 * matches a bind address as the source address.
  	 */
  	sctp_read_lock(addr_lock);
  	list_for_each(pos, &bp->address_list) {
  		laddr = list_entry(pos, struct sctp_sockaddr_entry, list);

  		if ((laddr->use_as_src) &&

  		    (AF_INET == laddr->a.sa.sa_family)) {
  			fl.fl4_src = laddr->a.v4.sin_addr.s_addr;

  			if (!ip_route_output_key(&rt, &fl)) {
  				dst = &rt->u.dst;
  				goto out_unlock;
  			}
  		}
  	}
  
  out_unlock:
  	sctp_read_unlock(addr_lock);
  out:
  	if (dst)
  		SCTP_DEBUG_PRINTK("rt_dst:%u.%u.%u.%u, rt_src:%u.%u.%u.%u
  ",

  				  NIPQUAD(rt->rt_dst), NIPQUAD(rt->rt_src));

  	else
  		SCTP_DEBUG_PRINTK("NO ROUTE
  ");
  
  	return dst;
  }
  
  /* For v4, the source address is cached in the route entry(dst). So no need
   * to cache it separately and hence this is an empty routine.
   */
  static void sctp_v4_get_saddr(struct sctp_association *asoc,
  			      struct dst_entry *dst,
  			      union sctp_addr *daddr,
  			      union sctp_addr *saddr)
  {
  	struct rtable *rt = (struct rtable *)dst;

  	if (!asoc)
  		return;

  	if (rt) {
  		saddr->v4.sin_family = AF_INET;

  		saddr->v4.sin_port = htons(asoc->base.bind_addr.port);

  		saddr->v4.sin_addr.s_addr = rt->rt_src;

  	}
  }
  
  /* What interface did this skb arrive on? */
  static int sctp_v4_skb_iif(const struct sk_buff *skb)
  {

  	return ((struct rtable *)skb->dst)->rt_iif;

  }
  
  /* Was this packet marked by Explicit Congestion Notification? */
  static int sctp_v4_is_ce(const struct sk_buff *skb)
  {

  	return INET_ECN_is_ce(ip_hdr(skb)->tos);

  }
  
  /* Create and initialize a new sk for the socket returned by accept(). */
  static struct sock *sctp_v4_create_accept_sk(struct sock *sk,
  					     struct sctp_association *asoc)
  {
  	struct inet_sock *inet = inet_sk(sk);
  	struct inet_sock *newinet;
  	struct sock *newsk = sk_alloc(PF_INET, GFP_KERNEL, sk->sk_prot, 1);
  
  	if (!newsk)
  		goto out;
  
  	sock_init_data(NULL, newsk);
  
  	newsk->sk_type = SOCK_STREAM;
  
  	newsk->sk_no_check = sk->sk_no_check;
  	newsk->sk_reuse = sk->sk_reuse;
  	newsk->sk_shutdown = sk->sk_shutdown;
  
  	newsk->sk_destruct = inet_sock_destruct;
  	newsk->sk_family = PF_INET;
  	newsk->sk_protocol = IPPROTO_SCTP;
  	newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
  	sock_reset_flag(newsk, SOCK_ZAPPED);
  
  	newinet = inet_sk(newsk);
  
  	/* Initialize sk's sport, dport, rcv_saddr and daddr for
  	 * getsockname() and getpeername()
  	 */
  	newinet->sport = inet->sport;
  	newinet->saddr = inet->saddr;
  	newinet->rcv_saddr = inet->rcv_saddr;
  	newinet->dport = htons(asoc->peer.port);
  	newinet->daddr = asoc->peer.primary_addr.v4.sin_addr.s_addr;
  	newinet->pmtudisc = inet->pmtudisc;

  	newinet->id = asoc->next_tsn ^ jiffies;

  
  	newinet->uc_ttl = -1;
  	newinet->mc_loop = 1;
  	newinet->mc_ttl = 1;
  	newinet->mc_index = 0;
  	newinet->mc_list = NULL;

  	sk_refcnt_debug_inc(newsk);

  
  	if (newsk->sk_prot->init(newsk)) {
  		sk_common_release(newsk);
  		newsk = NULL;
  	}
  
  out:
  	return newsk;
  }
  
  /* Map address, empty for v4 family */
  static void sctp_v4_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
  {
  	/* Empty */
  }
  
  /* Dump the v4 addr to the seq file. */
  static void sctp_v4_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
  {
  	seq_printf(seq, "%d.%d.%d.%d ", NIPQUAD(addr->v4.sin_addr));
  }

  /* Event handler for inet address addition/deletion events.  */

  static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
  			       void *ptr)

  {

  	struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
  	struct sctp_sockaddr_entry *addr;
  	struct list_head *pos, *temp;

  	switch (ev) {
  	case NETDEV_UP:
  		addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
  		if (addr) {
  			addr->a.v4.sin_family = AF_INET;
  			addr->a.v4.sin_port = 0;
  			addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
  			list_add_tail(&addr->list, &sctp_local_addr_list);
  		}
  		break;
  	case NETDEV_DOWN:
  		list_for_each_safe(pos, temp, &sctp_local_addr_list) {
  			addr = list_entry(pos, struct sctp_sockaddr_entry, list);
  			if (addr->a.v4.sin_addr.s_addr == ifa->ifa_local) {
  				list_del(pos);
  				kfree(addr);
  				break;
  			}
  		}
  
  		break;
  	}

  
  	return NOTIFY_DONE;
  }
  
  /*
   * Initialize the control inode/socket with a control endpoint data
   * structure.  This endpoint is reserved exclusively for the OOTB processing.
   */
  static int sctp_ctl_sock_init(void)
  {
  	int err;
  	sa_family_t family;
  
  	if (sctp_get_pf_specific(PF_INET6))
  		family = PF_INET6;
  	else
  		family = PF_INET;
  
  	err = sock_create_kern(family, SOCK_SEQPACKET, IPPROTO_SCTP,
  			       &sctp_ctl_socket);
  	if (err < 0) {
  		printk(KERN_ERR
  		       "SCTP: Failed to create the SCTP control socket.
  ");
  		return err;
  	}
  	sctp_ctl_socket->sk->sk_allocation = GFP_ATOMIC;
  	inet_sk(sctp_ctl_socket->sk)->uc_ttl = -1;
  
  	return 0;
  }
  
  /* Register address family specific functions. */
  int sctp_register_af(struct sctp_af *af)
  {
  	switch (af->sa_family) {
  	case AF_INET:
  		if (sctp_af_v4_specific)
  			return 0;
  		sctp_af_v4_specific = af;
  		break;
  	case AF_INET6:
  		if (sctp_af_v6_specific)
  			return 0;
  		sctp_af_v6_specific = af;
  		break;
  	default:
  		return 0;
  	}
  
  	INIT_LIST_HEAD(&af->list);
  	list_add_tail(&af->list, &sctp_address_families);
  	return 1;
  }
  
  /* Get the table of functions for manipulating a particular address
   * family.
   */
  struct sctp_af *sctp_get_af_specific(sa_family_t family)
  {
  	switch (family) {
  	case AF_INET:
  		return sctp_af_v4_specific;
  	case AF_INET6:
  		return sctp_af_v6_specific;
  	default:
  		return NULL;
  	}
  }
  
  /* Common code to initialize a AF_INET msg_name. */
  static void sctp_inet_msgname(char *msgname, int *addr_len)
  {
  	struct sockaddr_in *sin;
  
  	sin = (struct sockaddr_in *)msgname;
  	*addr_len = sizeof(struct sockaddr_in);
  	sin->sin_family = AF_INET;
  	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
  }
  
  /* Copy the primary address of the peer primary address as the msg_name. */
  static void sctp_inet_event_msgname(struct sctp_ulpevent *event, char *msgname,
  				    int *addr_len)
  {
  	struct sockaddr_in *sin, *sinfrom;
  
  	if (msgname) {
  		struct sctp_association *asoc;
  
  		asoc = event->asoc;
  		sctp_inet_msgname(msgname, addr_len);
  		sin = (struct sockaddr_in *)msgname;
  		sinfrom = &asoc->peer.primary_addr.v4;
  		sin->sin_port = htons(asoc->peer.port);
  		sin->sin_addr.s_addr = sinfrom->sin_addr.s_addr;
  	}
  }
  
  /* Initialize and copy out a msgname from an inbound skb. */
  static void sctp_inet_skb_msgname(struct sk_buff *skb, char *msgname, int *len)
  {

  	if (msgname) {

  		struct sctphdr *sh = sctp_hdr(skb);
  		struct sockaddr_in *sin = (struct sockaddr_in *)msgname;

  		sctp_inet_msgname(msgname, len);

  		sin->sin_port = sh->source;

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

  	}
  }
  
  /* Do we support this AF? */
  static int sctp_inet_af_supported(sa_family_t family, struct sctp_sock *sp)
  {
  	/* PF_INET only supports AF_INET addresses. */
  	return (AF_INET == family);
  }
  
  /* Address matching with wildcards allowed. */
  static int sctp_inet_cmp_addr(const union sctp_addr *addr1,
  			      const union sctp_addr *addr2,
  			      struct sctp_sock *opt)
  {
  	/* PF_INET only supports AF_INET addresses. */
  	if (addr1->sa.sa_family != addr2->sa.sa_family)
  		return 0;
  	if (INADDR_ANY == addr1->v4.sin_addr.s_addr ||
  	    INADDR_ANY == addr2->v4.sin_addr.s_addr)
  		return 1;
  	if (addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr)
  		return 1;
  
  	return 0;
  }
  
  /* Verify that provided sockaddr looks bindable.  Common verification has
   * already been taken care of.
   */
  static int sctp_inet_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
  {
  	return sctp_v4_available(addr, opt);
  }
  
  /* Verify that sockaddr looks sendable.  Common verification has already
   * been taken care of.
   */
  static int sctp_inet_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
  {
  	return 1;
  }
  
  /* Fill in Supported Address Type information for INIT and INIT-ACK
   * chunks.  Returns number of addresses supported.
   */
  static int sctp_inet_supported_addrs(const struct sctp_sock *opt,

  				     __be16 *types)

  {
  	types[0] = SCTP_PARAM_IPV4_ADDRESS;
  	return 1;
  }
  
  /* Wrapper routine that calls the ip transmit routine. */
  static inline int sctp_v4_xmit(struct sk_buff *skb,
  			       struct sctp_transport *transport, int ipfragok)
  {
  	SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, "
  			  "src:%u.%u.%u.%u, dst:%u.%u.%u.%u
  ",
  			  __FUNCTION__, skb, skb->len,
  			  NIPQUAD(((struct rtable *)skb->dst)->rt_src),
  			  NIPQUAD(((struct rtable *)skb->dst)->rt_dst));
  
  	SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);

  	return ip_queue_xmit(skb, ipfragok);

  }
  
  static struct sctp_af sctp_ipv4_specific;
  
  static struct sctp_pf sctp_pf_inet = {
  	.event_msgname = sctp_inet_event_msgname,
  	.skb_msgname   = sctp_inet_skb_msgname,
  	.af_supported  = sctp_inet_af_supported,
  	.cmp_addr      = sctp_inet_cmp_addr,
  	.bind_verify   = sctp_inet_bind_verify,
  	.send_verify   = sctp_inet_send_verify,
  	.supported_addrs = sctp_inet_supported_addrs,
  	.create_accept_sk = sctp_v4_create_accept_sk,
  	.addr_v4map	= sctp_v4_addr_v4map,
  	.af            = &sctp_ipv4_specific,
  };
  
  /* Notifier for inetaddr addition/deletion events.  */
  static struct notifier_block sctp_inetaddr_notifier = {
  	.notifier_call = sctp_inetaddr_event,
  };
  
  /* Socket operations.  */

  static const struct proto_ops inet_seqpacket_ops = {

  	.family		   = PF_INET,
  	.owner		   = THIS_MODULE,
  	.release	   = inet_release,	/* Needs to be wrapped... */
  	.bind		   = inet_bind,
  	.connect	   = inet_dgram_connect,
  	.socketpair	   = sock_no_socketpair,
  	.accept		   = inet_accept,
  	.getname	   = inet_getname,	/* Semantics are different.  */
  	.poll		   = sctp_poll,
  	.ioctl		   = inet_ioctl,
  	.listen		   = sctp_inet_listen,
  	.shutdown	   = inet_shutdown,	/* Looks harmless.  */
  	.setsockopt	   = sock_common_setsockopt, /* IP_SOL IP_OPTION is a problem */
  	.getsockopt	   = sock_common_getsockopt,
  	.sendmsg	   = inet_sendmsg,
  	.recvmsg	   = sock_common_recvmsg,
  	.mmap		   = sock_no_mmap,
  	.sendpage	   = sock_no_sendpage,

  #ifdef CONFIG_COMPAT

  	.compat_setsockopt = compat_sock_common_setsockopt,
  	.compat_getsockopt = compat_sock_common_getsockopt,

  #endif

  };
  
  /* Registration with AF_INET family.  */
  static struct inet_protosw sctp_seqpacket_protosw = {
  	.type       = SOCK_SEQPACKET,
  	.protocol   = IPPROTO_SCTP,
  	.prot       = &sctp_prot,
  	.ops        = &inet_seqpacket_ops,
  	.capability = -1,
  	.no_check   = 0,
  	.flags      = SCTP_PROTOSW_FLAG
  };
  static struct inet_protosw sctp_stream_protosw = {
  	.type       = SOCK_STREAM,
  	.protocol   = IPPROTO_SCTP,
  	.prot       = &sctp_prot,
  	.ops        = &inet_seqpacket_ops,
  	.capability = -1,
  	.no_check   = 0,
  	.flags      = SCTP_PROTOSW_FLAG
  };
  
  /* Register with IP layer.  */
  static struct net_protocol sctp_protocol = {
  	.handler     = sctp_rcv,
  	.err_handler = sctp_v4_err,
  	.no_policy   = 1,
  };
  
  /* IPv4 address related functions.  */
  static struct sctp_af sctp_ipv4_specific = {

  	.sa_family	   = AF_INET,
  	.sctp_xmit	   = sctp_v4_xmit,
  	.setsockopt	   = ip_setsockopt,
  	.getsockopt	   = ip_getsockopt,
  	.get_dst	   = sctp_v4_get_dst,
  	.get_saddr	   = sctp_v4_get_saddr,
  	.copy_addrlist	   = sctp_v4_copy_addrlist,
  	.from_skb	   = sctp_v4_from_skb,
  	.from_sk	   = sctp_v4_from_sk,
  	.to_sk_saddr	   = sctp_v4_to_sk_saddr,
  	.to_sk_daddr	   = sctp_v4_to_sk_daddr,
  	.from_addr_param   = sctp_v4_from_addr_param,
  	.to_addr_param	   = sctp_v4_to_addr_param,
  	.dst_saddr	   = sctp_v4_dst_saddr,
  	.cmp_addr	   = sctp_v4_cmp_addr,
  	.addr_valid	   = sctp_v4_addr_valid,
  	.inaddr_any	   = sctp_v4_inaddr_any,
  	.is_any		   = sctp_v4_is_any,
  	.available	   = sctp_v4_available,
  	.scope		   = sctp_v4_scope,
  	.skb_iif	   = sctp_v4_skb_iif,
  	.is_ce		   = sctp_v4_is_ce,
  	.seq_dump_addr	   = sctp_v4_seq_dump_addr,
  	.net_header_len	   = sizeof(struct iphdr),
  	.sockaddr_len	   = sizeof(struct sockaddr_in),

  #ifdef CONFIG_COMPAT

  	.compat_setsockopt = compat_ip_setsockopt,
  	.compat_getsockopt = compat_ip_getsockopt,

  #endif

  };
  
  struct sctp_pf *sctp_get_pf_specific(sa_family_t family) {
  
  	switch (family) {
  	case PF_INET:
  		return sctp_pf_inet_specific;
  	case PF_INET6:
  		return sctp_pf_inet6_specific;
  	default:
  		return NULL;
  	}
  }
  
  /* Register the PF specific function table.  */
  int sctp_register_pf(struct sctp_pf *pf, sa_family_t family)
  {
  	switch (family) {
  	case PF_INET:
  		if (sctp_pf_inet_specific)
  			return 0;
  		sctp_pf_inet_specific = pf;
  		break;
  	case PF_INET6:
  		if (sctp_pf_inet6_specific)
  			return 0;
  		sctp_pf_inet6_specific = pf;
  		break;
  	default:
  		return 0;
  	}
  	return 1;
  }
  
  static int __init init_sctp_mibs(void)
  {
  	sctp_statistics[0] = alloc_percpu(struct sctp_mib);
  	if (!sctp_statistics[0])
  		return -ENOMEM;
  	sctp_statistics[1] = alloc_percpu(struct sctp_mib);
  	if (!sctp_statistics[1]) {
  		free_percpu(sctp_statistics[0]);
  		return -ENOMEM;
  	}
  	return 0;
  
  }
  
  static void cleanup_sctp_mibs(void)
  {
  	free_percpu(sctp_statistics[0]);
  	free_percpu(sctp_statistics[1]);
  }
  
  /* Initialize the universe into something sensible.  */
  SCTP_STATIC __init int sctp_init(void)
  {
  	int i;
  	int status = -EINVAL;
  	unsigned long goal;
  	int order;
  
  	/* SCTP_DEBUG sanity check. */
  	if (!sctp_sanity_check())
  		goto out;

  	/* Allocate bind_bucket and chunk caches. */

  	status = -ENOBUFS;
  	sctp_bucket_cachep = kmem_cache_create("sctp_bind_bucket",
  					       sizeof(struct sctp_bind_bucket),
  					       0, SLAB_HWCACHE_ALIGN,

  					       NULL);

  	if (!sctp_bucket_cachep)

  		goto out;

  
  	sctp_chunk_cachep = kmem_cache_create("sctp_chunk",
  					       sizeof(struct sctp_chunk),
  					       0, SLAB_HWCACHE_ALIGN,

  					       NULL);

  	if (!sctp_chunk_cachep)
  		goto err_chunk_cachep;
  
  	/* Allocate and initialise sctp mibs.  */
  	status = init_sctp_mibs();
  	if (status)
  		goto err_init_mibs;
  
  	/* Initialize proc fs directory.  */
  	status = sctp_proc_init();
  	if (status)
  		goto err_init_proc;
  
  	/* Initialize object count debugging.  */
  	sctp_dbg_objcnt_init();
  
  	/* Initialize the SCTP specific PF functions. */
  	sctp_register_pf(&sctp_pf_inet, PF_INET);
  	/*
  	 * 14. Suggested SCTP Protocol Parameter Values
  	 */
  	/* The following protocol parameters are RECOMMENDED:  */
  	/* RTO.Initial              - 3  seconds */
  	sctp_rto_initial		= SCTP_RTO_INITIAL;
  	/* RTO.Min                  - 1  second */
  	sctp_rto_min	 		= SCTP_RTO_MIN;
  	/* RTO.Max                 -  60 seconds */
  	sctp_rto_max 			= SCTP_RTO_MAX;
  	/* RTO.Alpha                - 1/8 */
  	sctp_rto_alpha	        	= SCTP_RTO_ALPHA;
  	/* RTO.Beta                 - 1/4 */
  	sctp_rto_beta			= SCTP_RTO_BETA;
  
  	/* Valid.Cookie.Life        - 60  seconds */

  	sctp_valid_cookie_life		= SCTP_DEFAULT_COOKIE_LIFE;

  
  	/* Whether Cookie Preservative is enabled(1) or not(0) */
  	sctp_cookie_preserve_enable 	= 1;
  
  	/* Max.Burst		    - 4 */

  	sctp_max_burst 			= SCTP_DEFAULT_MAX_BURST;

  
  	/* Association.Max.Retrans  - 10 attempts
  	 * Path.Max.Retrans         - 5  attempts (per destination address)
  	 * Max.Init.Retransmits     - 8  attempts
  	 */
  	sctp_max_retrans_association 	= 10;
  	sctp_max_retrans_path		= 5;
  	sctp_max_retrans_init		= 8;

  	/* Sendbuffer growth	    - do per-socket accounting */
  	sctp_sndbuf_policy		= 0;

  	/* Rcvbuffer growth	    - do per-socket accounting */
  	sctp_rcvbuf_policy		= 0;

  	/* HB.interval              - 30 seconds */

  	sctp_hb_interval		= SCTP_DEFAULT_TIMEOUT_HEARTBEAT;
  
  	/* delayed SACK timeout */
  	sctp_sack_timeout		= SCTP_DEFAULT_TIMEOUT_SACK;

  
  	/* Implementation specific variables. */
  
  	/* Initialize default stream count setup information. */
  	sctp_max_instreams    		= SCTP_DEFAULT_INSTREAMS;
  	sctp_max_outstreams   		= SCTP_DEFAULT_OUTSTREAMS;
  
  	/* Initialize handle used for association ids. */
  	idr_init(&sctp_assocs_id);
  
  	/* Size and allocate the association hash table.
  	 * The methodology is similar to that of the tcp hash tables.
  	 */
  	if (num_physpages >= (128 * 1024))
  		goal = num_physpages >> (22 - PAGE_SHIFT);
  	else
  		goal = num_physpages >> (24 - PAGE_SHIFT);
  
  	for (order = 0; (1UL << order) < goal; order++)
  		;
  
  	do {
  		sctp_assoc_hashsize = (1UL << order) * PAGE_SIZE /
  					sizeof(struct sctp_hashbucket);
  		if ((sctp_assoc_hashsize > (64 * 1024)) && order > 0)
  			continue;
  		sctp_assoc_hashtable = (struct sctp_hashbucket *)
  					__get_free_pages(GFP_ATOMIC, order);
  	} while (!sctp_assoc_hashtable && --order > 0);
  	if (!sctp_assoc_hashtable) {
  		printk(KERN_ERR "SCTP: Failed association hash alloc.
  ");
  		status = -ENOMEM;
  		goto err_ahash_alloc;
  	}
  	for (i = 0; i < sctp_assoc_hashsize; i++) {
  		rwlock_init(&sctp_assoc_hashtable[i].lock);
  		sctp_assoc_hashtable[i].chain = NULL;
  	}
  
  	/* Allocate and initialize the endpoint hash table.  */
  	sctp_ep_hashsize = 64;
  	sctp_ep_hashtable = (struct sctp_hashbucket *)
  		kmalloc(64 * sizeof(struct sctp_hashbucket), GFP_KERNEL);
  	if (!sctp_ep_hashtable) {
  		printk(KERN_ERR "SCTP: Failed endpoint_hash alloc.
  ");
  		status = -ENOMEM;
  		goto err_ehash_alloc;
  	}
  	for (i = 0; i < sctp_ep_hashsize; i++) {
  		rwlock_init(&sctp_ep_hashtable[i].lock);
  		sctp_ep_hashtable[i].chain = NULL;
  	}
  
  	/* Allocate and initialize the SCTP port hash table.  */
  	do {
  		sctp_port_hashsize = (1UL << order) * PAGE_SIZE /
  					sizeof(struct sctp_bind_hashbucket);
  		if ((sctp_port_hashsize > (64 * 1024)) && order > 0)
  			continue;
  		sctp_port_hashtable = (struct sctp_bind_hashbucket *)
  					__get_free_pages(GFP_ATOMIC, order);
  	} while (!sctp_port_hashtable && --order > 0);
  	if (!sctp_port_hashtable) {
  		printk(KERN_ERR "SCTP: Failed bind hash alloc.");
  		status = -ENOMEM;
  		goto err_bhash_alloc;
  	}
  	for (i = 0; i < sctp_port_hashsize; i++) {
  		spin_lock_init(&sctp_port_hashtable[i].lock);
  		sctp_port_hashtable[i].chain = NULL;
  	}
  
  	spin_lock_init(&sctp_port_alloc_lock);
  	sctp_port_rover = sysctl_local_port_range[0] - 1;
  
  	printk(KERN_INFO "SCTP: Hash tables configured "
  			 "(established %d bind %d)
  ",
  		sctp_assoc_hashsize, sctp_port_hashsize);
  
  	/* Disable ADDIP by default. */
  	sctp_addip_enable = 0;
  
  	/* Enable PR-SCTP by default. */
  	sctp_prsctp_enable = 1;
  
  	sctp_sysctl_register();
  
  	INIT_LIST_HEAD(&sctp_address_families);
  	sctp_register_af(&sctp_ipv4_specific);

  	status = proto_register(&sctp_prot, 1);
  	if (status)
  		goto err_proto_register;
  
  	/* Register SCTP(UDP and TCP style) with socket layer.  */
  	inet_register_protosw(&sctp_seqpacket_protosw);
  	inet_register_protosw(&sctp_stream_protosw);

  	status = sctp_v6_init();
  	if (status)
  		goto err_v6_init;
  
  	/* Initialize the control inode/socket for handling OOTB packets.  */
  	if ((status = sctp_ctl_sock_init())) {
  		printk (KERN_ERR
  			"SCTP: Failed to initialize the SCTP control sock.
  ");
  		goto err_ctl_sock_init;
  	}
  
  	/* Initialize the local address list. */
  	INIT_LIST_HEAD(&sctp_local_addr_list);

  	sctp_get_local_addr_list();

  
  	/* Register notifier for inet address additions/deletions. */
  	register_inetaddr_notifier(&sctp_inetaddr_notifier);

  	/* Register SCTP with inet layer.  */
  	if (inet_add_protocol(&sctp_protocol, IPPROTO_SCTP) < 0) {
  		status = -EAGAIN;
  		goto err_add_protocol;
  	}
  
  	/* Register SCTP with inet6 layer.  */
  	status = sctp_v6_add_protocol();
  	if (status)
  		goto err_v6_add_protocol;

  	__unsafe(THIS_MODULE);
  	status = 0;
  out:
  	return status;

  err_v6_add_protocol:
  	inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
  	unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
  err_add_protocol:
  	sctp_free_local_addr_list();
  	sock_release(sctp_ctl_socket);

  err_ctl_sock_init:
  	sctp_v6_exit();
  err_v6_init:

  	inet_unregister_protosw(&sctp_stream_protosw);
  	inet_unregister_protosw(&sctp_seqpacket_protosw);
  	proto_unregister(&sctp_prot);
  err_proto_register:

  	sctp_sysctl_unregister();
  	list_del(&sctp_ipv4_specific.list);
  	free_pages((unsigned long)sctp_port_hashtable,
  		   get_order(sctp_port_hashsize *
  			     sizeof(struct sctp_bind_hashbucket)));
  err_bhash_alloc:
  	kfree(sctp_ep_hashtable);
  err_ehash_alloc:
  	free_pages((unsigned long)sctp_assoc_hashtable,
  		   get_order(sctp_assoc_hashsize *
  			     sizeof(struct sctp_hashbucket)));
  err_ahash_alloc:
  	sctp_dbg_objcnt_exit();

  	sctp_proc_exit();

  err_init_proc:

  	cleanup_sctp_mibs();
  err_init_mibs:
  	kmem_cache_destroy(sctp_chunk_cachep);
  err_chunk_cachep:
  	kmem_cache_destroy(sctp_bucket_cachep);

  	goto out;
  }
  
  /* Exit handler for the SCTP protocol.  */
  SCTP_STATIC __exit void sctp_exit(void)
  {
  	/* BUG.  This should probably do something useful like clean
  	 * up all the remaining associations and all that memory.
  	 */

  	/* Unregister with inet6/inet layers. */
  	sctp_v6_del_protocol();
  	inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);

  
  	/* Free the local address list.  */
  	sctp_free_local_addr_list();
  
  	/* Free the control endpoint.  */
  	sock_release(sctp_ctl_socket);

  	/* Cleanup v6 initializations. */

  	sctp_v6_exit();

  
  	/* Unregister with socket layer. */
  	inet_unregister_protosw(&sctp_stream_protosw);
  	inet_unregister_protosw(&sctp_seqpacket_protosw);
  
  	/* Unregister notifier for inet address additions/deletions. */
  	unregister_inetaddr_notifier(&sctp_inetaddr_notifier);

  	sctp_sysctl_unregister();
  	list_del(&sctp_ipv4_specific.list);
  
  	free_pages((unsigned long)sctp_assoc_hashtable,
  		   get_order(sctp_assoc_hashsize *
  			     sizeof(struct sctp_hashbucket)));
  	kfree(sctp_ep_hashtable);
  	free_pages((unsigned long)sctp_port_hashtable,
  		   get_order(sctp_port_hashsize *
  			     sizeof(struct sctp_bind_hashbucket)));

  	sctp_dbg_objcnt_exit();
  	sctp_proc_exit();
  	cleanup_sctp_mibs();

  	kmem_cache_destroy(sctp_chunk_cachep);
  	kmem_cache_destroy(sctp_bucket_cachep);

  	proto_unregister(&sctp_prot);
  }
  
  module_init(sctp_init);
  module_exit(sctp_exit);

  /*
   * __stringify doesn't likes enums, so use IPPROTO_SCTP value (132) directly.
   */
  MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-132");

  MODULE_ALIAS("net-pf-" __stringify(PF_INET6) "-proto-132");

  MODULE_AUTHOR("Linux Kernel SCTP developers <lksctp-developers@lists.sourceforge.net>");
  MODULE_DESCRIPTION("Support for the SCTP protocol (RFC2960)");
  MODULE_LICENSE("GPL");