text: /* SCTP kernel implementation
   * (C) Copyright IBM Corp. 2001, 2004
   * Copyright (c) 1999-2000 Cisco, Inc.
   * Copyright (c) 1999-2001 Motorola, Inc.
   * Copyright (c) 2001-2003 Intel Corp.
   * Copyright (c) 2001-2002 Nokia, Inc.
   * Copyright (c) 2001 La Monte H.P. Yarroll
   *
   * This file is part of the SCTP kernel implementation
   *
   * These functions interface with the sockets layer to implement the
   * SCTP Extensions for the Sockets API.
   *
   * Note that the descriptions from the specification are USER level
   * functions--this file is the functions which populate the struct proto
   * for SCTP which is the BOTTOM of the sockets interface.
   *
   * This SCTP 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.
   *
   * This SCTP 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>
   *    Narasimha Budihal     <narsi@refcode.org>
   *    Karl Knutson          <karl@athena.chicago.il.us>
   *    Jon Grimm             <jgrimm@us.ibm.com>
   *    Xingang Guo           <xingang.guo@intel.com>
   *    Daisy Chang           <daisyc@us.ibm.com>
   *    Sridhar Samudrala     <samudrala@us.ibm.com>
   *    Inaky Perez-Gonzalez  <inaky.gonzalez@intel.com>
   *    Ardelle Fan	    <ardelle.fan@intel.com>
   *    Ryan Layer	    <rmlayer@us.ibm.com>
   *    Anup Pemmaiah         <pemmaiah@cc.usu.edu>
   *    Kevin Gao             <kevin.gao@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/types.h>
  #include <linux/kernel.h>
  #include <linux/wait.h>
  #include <linux/time.h>
  #include <linux/ip.h>
  #include <linux/capability.h>
  #include <linux/fcntl.h>
  #include <linux/poll.h>
  #include <linux/init.h>
  #include <linux/crypto.h>
  #include <linux/slab.h>
  
  #include <net/ip.h>
  #include <net/icmp.h>
  #include <net/route.h>
  #include <net/ipv6.h>
  #include <net/inet_common.h>
  
  #include <linux/socket.h> /* for sa_family_t */
  #include <net/sock.h>
  #include <net/sctp/sctp.h>
  #include <net/sctp/sm.h>
  
  /* WARNING:  Please do not remove the SCTP_STATIC attribute to
   * any of the functions below as they are used to export functions
   * used by a project regression testsuite.
   */
  
  /* Forward declarations for internal helper functions. */
  static int sctp_writeable(struct sock *sk);
  static void sctp_wfree(struct sk_buff *skb);
  static int sctp_wait_for_sndbuf(struct sctp_association *, long *timeo_p,
  				size_t msg_len);
  static int sctp_wait_for_packet(struct sock * sk, int *err, long *timeo_p);
  static int sctp_wait_for_connect(struct sctp_association *, long *timeo_p);
  static int sctp_wait_for_accept(struct sock *sk, long timeo);
  static void sctp_wait_for_close(struct sock *sk, long timeo);
  static struct sctp_af *sctp_sockaddr_af(struct sctp_sock *opt,
  					union sctp_addr *addr, int len);
  static int sctp_bindx_add(struct sock *, struct sockaddr *, int);
  static int sctp_bindx_rem(struct sock *, struct sockaddr *, int);
  static int sctp_send_asconf_add_ip(struct sock *, struct sockaddr *, int);
  static int sctp_send_asconf_del_ip(struct sock *, struct sockaddr *, int);
  static int sctp_send_asconf(struct sctp_association *asoc,
  			    struct sctp_chunk *chunk);
  static int sctp_do_bind(struct sock *, union sctp_addr *, int);
  static int sctp_autobind(struct sock *sk);
  static void sctp_sock_migrate(struct sock *, struct sock *,
  			      struct sctp_association *, sctp_socket_type_t);
  static char *sctp_hmac_alg = SCTP_COOKIE_HMAC_ALG;
  
  extern struct kmem_cache *sctp_bucket_cachep;
  extern int sysctl_sctp_mem[3];
  extern int sysctl_sctp_rmem[3];
  extern int sysctl_sctp_wmem[3];
  
  static int sctp_memory_pressure;
  static atomic_t sctp_memory_allocated;
  struct percpu_counter sctp_sockets_allocated;
  
  static void sctp_enter_memory_pressure(struct sock *sk)
  {
  	sctp_memory_pressure = 1;
  }
  
  
  /* Get the sndbuf space available at the time on the association.  */
  static inline int sctp_wspace(struct sctp_association *asoc)
  {
  	int amt;
  
  	if (asoc->ep->sndbuf_policy)
  		amt = asoc->sndbuf_used;
  	else
  		amt = sk_wmem_alloc_get(asoc->base.sk);
  
  	if (amt >= asoc->base.sk->sk_sndbuf) {
  		if (asoc->base.sk->sk_userlocks & SOCK_SNDBUF_LOCK)
  			amt = 0;
  		else {
  			amt = sk_stream_wspace(asoc->base.sk);
  			if (amt < 0)
  				amt = 0;
  		}
  	} else {
  		amt = asoc->base.sk->sk_sndbuf - amt;
  	}
  	return amt;
  }
  
  /* Increment the used sndbuf space count of the corresponding association by
   * the size of the outgoing data chunk.
   * Also, set the skb destructor for sndbuf accounting later.
   *
   * Since it is always 1-1 between chunk and skb, and also a new skb is always
   * allocated for chunk bundling in sctp_packet_transmit(), we can use the
   * destructor in the data chunk skb for the purpose of the sndbuf space
   * tracking.
   */
  static inline void sctp_set_owner_w(struct sctp_chunk *chunk)
  {
  	struct sctp_association *asoc = chunk->asoc;
  	struct sock *sk = asoc->base.sk;
  
  	/* The sndbuf space is tracked per association.  */
  	sctp_association_hold(asoc);
  
  	skb_set_owner_w(chunk->skb, sk);
  
  	chunk->skb->destructor = sctp_wfree;
  	/* Save the chunk pointer in skb for sctp_wfree to use later.  */
  	*((struct sctp_chunk **)(chunk->skb->cb)) = chunk;
  
  	asoc->sndbuf_used += SCTP_DATA_SNDSIZE(chunk) +
  				sizeof(struct sk_buff) +
  				sizeof(struct sctp_chunk);
  
  	atomic_add(sizeof(struct sctp_chunk), &sk->sk_wmem_alloc);
  	sk->sk_wmem_queued += chunk->skb->truesize;
  	sk_mem_charge(sk, chunk->skb->truesize);
  }
  
  /* Verify that this is a valid address. */
  static inline int sctp_verify_addr(struct sock *sk, union sctp_addr *addr,
  				   int len)
  {
  	struct sctp_af *af;
  
  	/* Verify basic sockaddr. */
  	af = sctp_sockaddr_af(sctp_sk(sk), addr, len);
  	if (!af)
  		return -EINVAL;
  
  	/* Is this a valid SCTP address?  */
  	if (!af->addr_valid(addr, sctp_sk(sk), NULL))
  		return -EINVAL;
  
  	if (!sctp_sk(sk)->pf->send_verify(sctp_sk(sk), (addr)))
  		return -EINVAL;
  
  	return 0;
  }
  
  /* Look up the association by its id.  If this is not a UDP-style
   * socket, the ID field is always ignored.
   */
  struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id)
  {
  	struct sctp_association *asoc = NULL;
  
  	/* If this is not a UDP-style socket, assoc id should be ignored. */
  	if (!sctp_style(sk, UDP)) {
  		/* Return NULL if the socket state is not ESTABLISHED. It
  		 * could be a TCP-style listening socket or a socket which
  		 * hasn't yet called connect() to establish an association.
  		 */
  		if (!sctp_sstate(sk, ESTABLISHED))
  			return NULL;
  
  		/* Get the first and the only association from the list. */
  		if (!list_empty(&sctp_sk(sk)->ep->asocs))
  			asoc = list_entry(sctp_sk(sk)->ep->asocs.next,
  					  struct sctp_association, asocs);
  		return asoc;
  	}
  
  	/* Otherwise this is a UDP-style socket. */
  	if (!id || (id == (sctp_assoc_t)-1))
  		return NULL;
  
  	spin_lock_bh(&sctp_assocs_id_lock);
  	asoc = (struct sctp_association *)idr_find(&sctp_assocs_id, (int)id);
  	spin_unlock_bh(&sctp_assocs_id_lock);
  
  	if (!asoc || (asoc->base.sk != sk) || asoc->base.dead)
  		return NULL;
  
  	return asoc;
  }
  
  /* Look up the transport from an address and an assoc id. If both address and
   * id are specified, the associations matching the address and the id should be
   * the same.
   */
  static struct sctp_transport *sctp_addr_id2transport(struct sock *sk,
  					      struct sockaddr_storage *addr,
  					      sctp_assoc_t id)
  {
  	struct sctp_association *addr_asoc = NULL, *id_asoc = NULL;
  	struct sctp_transport *transport;
  	union sctp_addr *laddr = (union sctp_addr *)addr;
  
  	addr_asoc = sctp_endpoint_lookup_assoc(sctp_sk(sk)->ep,
  					       laddr,
  					       &transport);
  
  	if (!addr_asoc)
  		return NULL;
  
  	id_asoc = sctp_id2assoc(sk, id);
  	if (id_asoc && (id_asoc != addr_asoc))
  		return NULL;
  
  	sctp_get_pf_specific(sk->sk_family)->addr_v4map(sctp_sk(sk),
  						(union sctp_addr *)addr);
  
  	return transport;
  }
  
  /* API 3.1.2 bind() - UDP Style Syntax
   * The syntax of bind() is,
   *
   *   ret = bind(int sd, struct sockaddr *addr, int addrlen);
   *
   *   sd      - the socket descriptor returned by socket().
   *   addr    - the address structure (struct sockaddr_in or struct
   *             sockaddr_in6 [RFC 2553]),
   *   addr_len - the size of the address structure.
   */
  SCTP_STATIC int sctp_bind(struct sock *sk, struct sockaddr *addr, int addr_len)
  {
  	int retval = 0;
  
  	sctp_lock_sock(sk);
  
  	SCTP_DEBUG_PRINTK("sctp_bind(sk: %p, addr: %p, addr_len: %d)\n",
  			  sk, addr, addr_len);
  
  	/* Disallow binding twice. */
  	if (!sctp_sk(sk)->ep->base.bind_addr.port)
  		retval = sctp_do_bind(sk, (union sctp_addr *)addr,
  				      addr_len);
  	else
  		retval = -EINVAL;
  
  	sctp_release_sock(sk);
  
  	return retval;
  }
  
  static long sctp_get_port_local(struct sock *, union sctp_addr *);
  
  /* Verify this is a valid sockaddr. */
  static struct sctp_af *sctp_sockaddr_af(struct sctp_sock *opt,
  					union sctp_addr *addr, int len)
  {
  	struct sctp_af *af;
  
  	/* Check minimum size.  */
  	if (len < sizeof (struct sockaddr))
  		return NULL;
  
  	/* V4 mapped address are really of AF_INET family */
  	if (addr->sa.sa_family == AF_INET6 &&
  	    ipv6_addr_v4mapped(&addr->v6.sin6_addr)) {
  		if (!opt->pf->af_supported(AF_INET, opt))
  			return NULL;
  	} else {
  		/* Does this PF support this AF? */
  		if (!opt->pf->af_supported(addr->sa.sa_family, opt))
  			return NULL;
  	}
  
  	/* If we get this far, af is valid. */
  	af = sctp_get_af_specific(addr->sa.sa_family);
  
  	if (len < af->sockaddr_len)
  		return NULL;
  
  	return af;
  }
  
  /* Bind a local address either to an endpoint or to an association.  */
  SCTP_STATIC int sctp_do_bind(struct sock *sk, union sctp_addr *addr, int len)
  {
  	struct sctp_sock *sp = sctp_sk(sk);
  	struct sctp_endpoint *ep = sp->ep;
  	struct sctp_bind_addr *bp = &ep->base.bind_addr;
  	struct sctp_af *af;
  	unsigned short snum;
  	int ret = 0;
  
  	/* Common sockaddr verification. */
  	af = sctp_sockaddr_af(sp, addr, len);
  	if (!af) {
  		SCTP_DEBUG_PRINTK("sctp_do_bind(sk: %p, newaddr: %p, len: %d) EINVAL\n",
  				  sk, addr, len);
  		return -EINVAL;
  	}
  
  	snum = ntohs(addr->v4.sin_port);
  
  	SCTP_DEBUG_PRINTK_IPADDR("sctp_do_bind(sk: %p, new addr: ",
  				 ", port: %d, new port: %d, len: %d)\n",
  				 sk,
  				 addr,
  				 bp->port, snum,
  				 len);
  
  	/* PF specific bind() address verification. */
  	if (!sp->pf->bind_verify(sp, addr))
  		return -EADDRNOTAVAIL;
  
  	/* We must either be unbound, or bind to the same port.
  	 * It's OK to allow 0 ports if we are already bound.
  	 * We'll just inhert an already bound port in this case
  	 */
  	if (bp->port) {
  		if (!snum)
  			snum = bp->port;
  		else if (snum != bp->port) {
  			SCTP_DEBUG_PRINTK("sctp_do_bind:"
  				  " New port %d does not match existing port "
  				  "%d.\n", snum, bp->port);
  			return -EINVAL;
  		}
  	}
  
  	if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
  		return -EACCES;
  
  	/* See if the address matches any of the addresses we may have
  	 * already bound before checking against other endpoints.
  	 */
  	if (sctp_bind_addr_match(bp, addr, sp))
  		return -EINVAL;
  
  	/* Make sure we are allowed to bind here.
  	 * The function sctp_get_port_local() does duplicate address
  	 * detection.
  	 */
  	addr->v4.sin_port = htons(snum);
  	if ((ret = sctp_get_port_local(sk, addr))) {
  		return -EADDRINUSE;
  	}
  
  	/* Refresh ephemeral port.  */
  	if (!bp->port)
  		bp->port = inet_sk(sk)->inet_num;
  
  	/* Add the address to the bind address list.
  	 * Use GFP_ATOMIC since BHs will be disabled.
  	 */
  	ret = sctp_add_bind_addr(bp, addr, SCTP_ADDR_SRC, GFP_ATOMIC);
  
  	/* Copy back into socket for getsockname() use. */
  	if (!ret) {
  		inet_sk(sk)->inet_sport = htons(inet_sk(sk)->inet_num);
  		af->to_sk_saddr(addr, sk);
  	}
  
  	return ret;
  }
  
   /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
   *
   * R1) One and only one ASCONF Chunk MAY be in transit and unacknowledged
   * at any one time.  If a sender, after sending an ASCONF chunk, decides
   * it needs to transfer another ASCONF Chunk, it MUST wait until the
   * ASCONF-ACK Chunk returns from the previous ASCONF Chunk before sending a
   * subsequent ASCONF. Note this restriction binds each side, so at any
   * time two ASCONF may be in-transit on any given association (one sent
   * from each endpoint).
   */
  static int sctp_send_asconf(struct sctp_association *asoc,
  			    struct sctp_chunk *chunk)
  {
  	int		retval = 0;
  
  	/* If there is an outstanding ASCONF chunk, queue it for later
  	 * transmission.
  	 */
  	if (asoc->addip_last_asconf) {
  		list_add_tail(&chunk->list, &asoc->addip_chunk_list);
  		goto out;
  	}
  
  	/* Hold the chunk until an ASCONF_ACK is received. */
  	sctp_chunk_hold(chunk);
  	retval = sctp_primitive_ASCONF(asoc, chunk);
  	if (retval)
  		sctp_chunk_free(chunk);
  	else
  		asoc->addip_last_asconf = chunk;
  
  out:
  	return retval;
  }
  
  /* Add a list of addresses as bind addresses to local endpoint or
   * association.
   *
   * Basically run through each address specified in the addrs/addrcnt
   * array/length pair, determine if it is IPv6 or IPv4 and call
   * sctp_do_bind() on it.
   *
   * If any of them fails, then the operation will be reversed and the
   * ones that were added will be removed.
   *
   * Only sctp_setsockopt_bindx() is supposed to call this function.
   */
  static int sctp_bindx_add(struct sock *sk, struct sockaddr *addrs, int addrcnt)
  {
  	int cnt;
  	int retval = 0;
  	void *addr_buf;
  	struct sockaddr *sa_addr;
  	struct sctp_af *af;
  
  	SCTP_DEBUG_PRINTK("sctp_bindx_add (sk: %p, addrs: %p, addrcnt: %d)\n",
  			  sk, addrs, addrcnt);
  
  	addr_buf = addrs;
  	for (cnt = 0; cnt < addrcnt; cnt++) {
  		/* The list may contain either IPv4 or IPv6 address;
  		 * determine the address length for walking thru the list.
  		 */
  		sa_addr = (struct sockaddr *)addr_buf;
  		af = sctp_get_af_specific(sa_addr->sa_family);
  		if (!af) {
  			retval = -EINVAL;
  			goto err_bindx_add;
  		}
  
  		retval = sctp_do_bind(sk, (union sctp_addr *)sa_addr,
  				      af->sockaddr_len);
  
  		addr_buf += af->sockaddr_len;
  
  err_bindx_add:
  		if (retval < 0) {
  			/* Failed. Cleanup the ones that have been added */
  			if (cnt > 0)
  				sctp_bindx_rem(sk, addrs, cnt);
  			return retval;
  		}
  	}
  
  	return retval;
  }
  
  /* Send an ASCONF chunk with Add IP address parameters to all the peers of the
   * associations that are part of the endpoint indicating that a list of local
   * addresses are added to the endpoint.
   *
   * If any of the addresses is already in the bind address list of the
   * association, we do not send the chunk for that association.  But it will not
   * affect other associations.
   *
   * Only sctp_setsockopt_bindx() is supposed to call this function.
   */
  static int sctp_send_asconf_add_ip(struct sock		*sk,
  				   struct sockaddr	*addrs,
  				   int 			addrcnt)
  {
  	struct sctp_sock		*sp;
  	struct sctp_endpoint		*ep;
  	struct sctp_association		*asoc;
  	struct sctp_bind_addr		*bp;
  	struct sctp_chunk		*chunk;
  	struct sctp_sockaddr_entry	*laddr;
  	union sctp_addr			*addr;
  	union sctp_addr			saveaddr;
  	void				*addr_buf;
  	struct sctp_af			*af;
  	struct list_head		*p;
  	int 				i;
  	int 				retval = 0;
  
  	if (!sctp_addip_enable)
  		return retval;
  
  	sp = sctp_sk(sk);
  	ep = sp->ep;
  
  	SCTP_DEBUG_PRINTK("%s: (sk: %p, addrs: %p, addrcnt: %d)\n",
  			  __func__, sk, addrs, addrcnt);
  
  	list_for_each_entry(asoc, &ep->asocs, asocs) {
  
  		if (!asoc->peer.asconf_capable)
  			continue;
  
  		if (asoc->peer.addip_disabled_mask & SCTP_PARAM_ADD_IP)
  			continue;
  
  		if (!sctp_state(asoc, ESTABLISHED))
  			continue;
  
  		/* Check if any address in the packed array of addresses is
  		 * in the bind address list of the association. If so,
  		 * do not send the asconf chunk to its peer, but continue with
  		 * other associations.
  		 */
  		addr_buf = addrs;
  		for (i = 0; i < addrcnt; i++) {
  			addr = (union sctp_addr *)addr_buf;
  			af = sctp_get_af_specific(addr->v4.sin_family);
  			if (!af) {
  				retval = -EINVAL;
  				goto out;
  			}
  
  			if (sctp_assoc_lookup_laddr(asoc, addr))
  				break;
  
  			addr_buf += af->sockaddr_len;
  		}
  		if (i < addrcnt)
  			continue;
  
  		/* Use the first valid address in bind addr list of
  		 * association as Address Parameter of ASCONF CHUNK.
  		 */
  		bp = &asoc->base.bind_addr;
  		p = bp->address_list.next;
  		laddr = list_entry(p, struct sctp_sockaddr_entry, list);
  		chunk = sctp_make_asconf_update_ip(asoc, &laddr->a, addrs,
  						   addrcnt, SCTP_PARAM_ADD_IP);
  		if (!chunk) {
  			retval = -ENOMEM;
  			goto out;
  		}
  
  		retval = sctp_send_asconf(asoc, chunk);
  		if (retval)
  			goto out;
  
  		/* Add the new addresses to the bind address list with
  		 * use_as_src set to 0.
  		 */
  		addr_buf = addrs;
  		for (i = 0; i < addrcnt; i++) {
  			addr = (union sctp_addr *)addr_buf;
  			af = sctp_get_af_specific(addr->v4.sin_family);
  			memcpy(&saveaddr, addr, af->sockaddr_len);
  			retval = sctp_add_bind_addr(bp, &saveaddr,
  						    SCTP_ADDR_NEW, GFP_ATOMIC);
  			addr_buf += af->sockaddr_len;
  		}
  	}
  
  out:
  	return retval;
  }
  
  /* Remove a list of addresses from bind addresses list.  Do not remove the
   * last address.
   *
   * Basically run through each address specified in the addrs/addrcnt
   * array/length pair, determine if it is IPv6 or IPv4 and call
   * sctp_del_bind() on it.
   *
   * If any of them fails, then the operation will be reversed and the
   * ones that were removed will be added back.
   *
   * At least one address has to be left; if only one address is
   * available, the operation will return -EBUSY.
   *
   * Only sctp_setsockopt_bindx() is supposed to call this function.
   */
  static int sctp_bindx_rem(struct sock *sk, struct sockaddr *addrs, int addrcnt)
  {
  	struct sctp_sock *sp = sctp_sk(sk);
  	struct sctp_endpoint *ep = sp->ep;
  	int cnt;
  	struct sctp_bind_addr *bp = &ep->base.bind_addr;
  	int retval = 0;
  	void *addr_buf;
  	union sctp_addr *sa_addr;
  	struct sctp_af *af;
  
  	SCTP_DEBUG_PRINTK("sctp_bindx_rem (sk: %p, addrs: %p, addrcnt: %d)\n",
  			  sk, addrs, addrcnt);
  
  	addr_buf = addrs;
  	for (cnt = 0; cnt < addrcnt; cnt++) {
  		/* If the bind address list is empty or if there is only one
  		 * bind address, there is nothing more to be removed (we need
  		 * at least one address here).
  		 */
  		if (list_empty(&bp->address_list) ||
  		    (sctp_list_single_entry(&bp->address_list))) {
  			retval = -EBUSY;
  			goto err_bindx_rem;
  		}
  
  		sa_addr = (union sctp_addr *)addr_buf;
  		af = sctp_get_af_specific(sa_addr->sa.sa_family);
  		if (!af) {
  			retval = -EINVAL;
  			goto err_bindx_rem;
  		}
  
  		if (!af->addr_valid(sa_addr, sp, NULL)) {
  			retval = -EADDRNOTAVAIL;
  			goto err_bindx_rem;
  		}
  
  		if (sa_addr->v4.sin_port != htons(bp->port)) {
  			retval = -EINVAL;
  			goto err_bindx_rem;
  		}
  
  		/* FIXME - There is probably a need to check if sk->sk_saddr and
  		 * sk->sk_rcv_addr are currently set to one of the addresses to
  		 * be removed. This is something which needs to be looked into
  		 * when we are fixing the outstanding issues with multi-homing
  		 * socket routing and failover schemes. Refer to comments in
  		 * sctp_do_bind(). -daisy
  		 */
  		retval = sctp_del_bind_addr(bp, sa_addr);
  
  		addr_buf += af->sockaddr_len;
  err_bindx_rem:
  		if (retval < 0) {
  			/* Failed. Add the ones that has been removed back */
  			if (cnt > 0)
  				sctp_bindx_add(sk, addrs, cnt);
  			return retval;
  		}
  	}
  
  	return retval;
  }
  
  /* Send an ASCONF chunk with Delete IP address parameters to all the peers of
   * the associations that are part of the endpoint indicating that a list of
   * local addresses are removed from the endpoint.
   *
   * If any of the addresses is already in the bind address list of the
   * association, we do not send the chunk for that association.  But it will not
   * affect other associations.
   *
   * Only sctp_setsockopt_bindx() is supposed to call this function.
   */
  static int sctp_send_asconf_del_ip(struct sock		*sk,
  				   struct sockaddr	*addrs,
  				   int			addrcnt)
  {
  	struct sctp_sock	*sp;
  	struct sctp_endpoint	*ep;
  	struct sctp_association	*asoc;
  	struct sctp_transport	*transport;
  	struct sctp_bind_addr	*bp;
  	struct sctp_chunk	*chunk;
  	union sctp_addr		*laddr;
  	void			*addr_buf;
  	struct sctp_af		*af;
  	struct sctp_sockaddr_entry *saddr;
  	int 			i;
  	int 			retval = 0;
  
  	if (!sctp_addip_enable)
  		return retval;
  
  	sp = sctp_sk(sk);
  	ep = sp->ep;
  
  	SCTP_DEBUG_PRINTK("%s: (sk: %p, addrs: %p, addrcnt: %d)\n",
  			  __func__, sk, addrs, addrcnt);
  
  	list_for_each_entry(asoc, &ep->asocs, asocs) {
  
  		if (!asoc->peer.asconf_capable)
  			continue;
  
  		if (asoc->peer.addip_disabled_mask & SCTP_PARAM_DEL_IP)
  			continue;
  
  		if (!sctp_state(asoc, ESTABLISHED))
  			continue;
  
  		/* Check if any address in the packed array of addresses is
  		 * not present in the bind address list of the association.
  		 * If so, do not send the asconf chunk to its peer, but
  		 * continue with other associations.
  		 */
  		addr_buf = addrs;
  		for (i = 0; i < addrcnt; i++) {
  			laddr = (union sctp_addr *)addr_buf;
  			af = sctp_get_af_specific(laddr->v4.sin_family);
  			if (!af) {
  				retval = -EINVAL;
  				goto out;
  			}
  
  			if (!sctp_assoc_lookup_laddr(asoc, laddr))
  				break;
  
  			addr_buf += af->sockaddr_len;
  		}
  		if (i < addrcnt)
  			continue;
  
  		/* Find one address in the association's bind address list
  		 * that is not in the packed array of addresses. This is to
  		 * make sure that we do not delete all the addresses in the
  		 * association.
  		 */
  		bp = &asoc->base.bind_addr;
  		laddr = sctp_find_unmatch_addr(bp, (union sctp_addr *)addrs,
  					       addrcnt, sp);
  		if (!laddr)
  			continue;
  
  		/* We do not need RCU protection throughout this loop
  		 * because this is done under a socket lock from the
  		 * setsockopt call.
  		 */
  		chunk = sctp_make_asconf_update_ip(asoc, laddr, addrs, addrcnt,
  						   SCTP_PARAM_DEL_IP);
  		if (!chunk) {
  			retval = -ENOMEM;
  			goto out;
  		}
  
  		/* Reset use_as_src flag for the addresses in the bind address
  		 * list that are to be deleted.
  		 */
  		addr_buf = addrs;
  		for (i = 0; i < addrcnt; i++) {
  			laddr = (union sctp_addr *)addr_buf;
  			af = sctp_get_af_specific(laddr->v4.sin_family);
  			list_for_each_entry(saddr, &bp->address_list, list) {
  				if (sctp_cmp_addr_exact(&saddr->a, laddr))
  					saddr->state = SCTP_ADDR_DEL;
  			}
  			addr_buf += af->sockaddr_len;
  		}
  
  		/* Update the route and saddr entries for all the transports
  		 * as some of the addresses in the bind address list are
  		 * about to be deleted and cannot be used as source addresses.
  		 */
  		list_for_each_entry(transport, &asoc->peer.transport_addr_list,
  					transports) {
  			dst_release(transport->dst);
  			sctp_transport_route(transport, NULL,
  					     sctp_sk(asoc->base.sk));
  		}
  
  		retval = sctp_send_asconf(asoc, chunk);
  	}
  out:
  	return retval;
  }
  
  /* Helper for tunneling sctp_bindx() requests through sctp_setsockopt()
   *
   * API 8.1
   * int sctp_bindx(int sd, struct sockaddr *addrs, int addrcnt,
   *                int flags);
   *
   * If sd is an IPv4 socket, the addresses passed must be IPv4 addresses.
   * If the sd is an IPv6 socket, the addresses passed can either be IPv4
   * or IPv6 addresses.
   *
   * A single address may be specified as INADDR_ANY or IN6ADDR_ANY, see
   * Section 3.1.2 for this usage.
   *
   * addrs is a pointer to an array of one or more socket addresses. Each
   * address is contained in its appropriate structure (i.e. struct
   * sockaddr_in or struct sockaddr_in6) the family of the address type
   * must be used to distinguish the address length (note that this
   * representation is termed a "packed array" of addresses). The caller
   * specifies the number of addresses in the array with addrcnt.
   *
   * On success, sctp_bindx() returns 0. On failure, sctp_bindx() returns
   * -1, and sets errno to the appropriate error code.
   *
   * For SCTP, the port given in each socket address must be the same, or
   * sctp_bindx() will fail, setting errno to EINVAL.
   *
   * The flags parameter is formed from the bitwise OR of zero or more of
   * the following currently defined flags:
   *
   * SCTP_BINDX_ADD_ADDR
   *
   * SCTP_BINDX_REM_ADDR
   *
   * SCTP_BINDX_ADD_ADDR directs SCTP to add the given addresses to the
   * association, and SCTP_BINDX_REM_ADDR directs SCTP to remove the given
   * addresses from the association. The two flags are mutually exclusive;
   * if both are given, sctp_bindx() will fail with EINVAL. A caller may
   * not remove all addresses from an association; sctp_bindx() will
   * reject such an attempt with EINVAL.
   *
   * An application can use sctp_bindx(SCTP_BINDX_ADD_ADDR) to associate
   * additional addresses with an endpoint after calling bind().  Or use
   * sctp_bindx(SCTP_BINDX_REM_ADDR) to remove some addresses a listening
   * socket is associated with so that no new association accepted will be
   * associated with those addresses. If the endpoint supports dynamic
   * address a SCTP_BINDX_REM_ADDR or SCTP_BINDX_ADD_ADDR may cause a
   * endpoint to send the appropriate message to the peer to change the
   * peers address lists.
   *
   * Adding and removing addresses from a connected association is
   * optional functionality. Implementations that do not support this
   * functionality should return EOPNOTSUPP.
   *
   * Basically do nothing but copying the addresses from user to kernel
   * land and invoking either sctp_bindx_add() or sctp_bindx_rem() on the sk.
   * This is used for tunneling the sctp_bindx() request through sctp_setsockopt()
   * from userspace.
   *
   * We don't use copy_from_user() for optimization: we first do the
   * sanity checks (buffer size -fast- and access check-healthy
   * pointer); if all of those succeed, then we can alloc the memory
   * (expensive operation) needed to copy the data to kernel. Then we do
   * the copying without checking the user space area
   * (__copy_from_user()).
   *
   * On exit there is no need to do sockfd_put(), sys_setsockopt() does
   * it.
   *
   * sk        The sk of the socket
   * addrs     The pointer to the addresses in user land
   * addrssize Size of the addrs buffer
   * op        Operation to perform (add or remove, see the flags of
   *           sctp_bindx)
   *
   * Returns 0 if ok, <0 errno code on error.
   */
  SCTP_STATIC int sctp_setsockopt_bindx(struct sock* sk,
  				      struct sockaddr __user *addrs,
  				      int addrs_size, int op)
  {
  	struct sockaddr *kaddrs;
  	int err;
  	int addrcnt = 0;
  	int walk_size = 0;
  	struct sockaddr *sa_addr;
  	void *addr_buf;
  	struct sctp_af *af;
  
  	SCTP_DEBUG_PRINTK("sctp_setsocktopt_bindx: sk %p addrs %p"
  			  " addrs_size %d opt %d\n", sk, addrs, addrs_size, op);
  
  	if (unlikely(addrs_size <= 0))
  		return -EINVAL;
  
  	/* Check the user passed a healthy pointer.  */
  	if (unlikely(!access_ok(VERIFY_READ, addrs, addrs_size)))
  		return -EFAULT;
  
  	/* Alloc space for the address array in kernel memory.  */
  	kaddrs = kmalloc(addrs_size, GFP_KERNEL);
  	if (unlikely(!kaddrs))
  		return -ENOMEM;
  
  	if (__copy_from_user(kaddrs, addrs, addrs_size)) {
  		kfree(kaddrs);
  		return -EFAULT;
  	}
  
  	/* Walk through the addrs buffer and count the number of addresses. */
  	addr_buf = kaddrs;
  	while (walk_size < addrs_size) {
  		sa_addr = (struct sockaddr *)addr_buf;
  		af = sctp_get_af_specific(sa_addr->sa_family);
  
  		/* If the address family is not supported or if this address
  		 * causes the address buffer to overflow return EINVAL.
  		 */
  		if (!af || (walk_size + af->sockaddr_len) > addrs_size) {
  			kfree(kaddrs);
  			return -EINVAL;
  		}
  		addrcnt++;
  		addr_buf += af->sockaddr_len;
  		walk_size += af->sockaddr_len;
  	}
  
  	/* Do the work. */
  	switch (op) {
  	case SCTP_BINDX_ADD_ADDR:
  		err = sctp_bindx_add(sk, kaddrs, addrcnt);
  		if (err)
  			goto out;
  		err = sctp_send_asconf_add_ip(sk, kaddrs, addrcnt);
  		break;
  
  	case SCTP_BINDX_REM_ADDR:
  		err = sctp_bindx_rem(sk, kaddrs, addrcnt);
  		if (err)
  			goto out;
  		err = sctp_send_asconf_del_ip(sk, kaddrs, addrcnt);
  		break;
  
  	default:
  		err = -EINVAL;
  		break;
  	}
  
  out:
  	kfree(kaddrs);
  
  	return err;
  }
  
  /* __sctp_connect(struct sock* sk, struct sockaddr *kaddrs, int addrs_size)
   *
   * Common routine for handling connect() and sctp_connectx().
   * Connect will come in with just a single address.
   */
  static int __sctp_connect(struct sock* sk,
  			  struct sockaddr *kaddrs,
  			  int addrs_size,
  			  sctp_assoc_t *assoc_id)
  {
  	struct sctp_sock *sp;
  	struct sctp_endpoint *ep;
  	struct sctp_association *asoc = NULL;
  	struct sctp_association *asoc2;
  	struct sctp_transport *transport;
  	union sctp_addr to;
  	struct sctp_af *af;
  	sctp_scope_t scope;
  	long timeo;
  	int err = 0;
  	int addrcnt = 0;
  	int walk_size = 0;
  	union sctp_addr *sa_addr = NULL;
  	void *addr_buf;
  	unsigned short port;
  	unsigned int f_flags = 0;
  
  	sp = sctp_sk(sk);
  	ep = sp->ep;
  
  	/* connect() cannot be done on a socket that is already in ESTABLISHED
  	 * state - UDP-style peeled off socket or a TCP-style socket that
  	 * is already connected.
  	 * It cannot be done even on a TCP-style listening socket.
  	 */
  	if (sctp_sstate(sk, ESTABLISHED) ||
  	    (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))) {
  		err = -EISCONN;
  		goto out_free;
  	}
  
  	/* Walk through the addrs buffer and count the number of addresses. */
  	addr_buf = kaddrs;
  	while (walk_size < addrs_size) {
  		sa_addr = (union sctp_addr *)addr_buf;
  		af = sctp_get_af_specific(sa_addr->sa.sa_family);
  		port = ntohs(sa_addr->v4.sin_port);
  
  		/* If the address family is not supported or if this address
  		 * causes the address buffer to overflow return EINVAL.
  		 */
  		if (!af || (walk_size + af->sockaddr_len) > addrs_size) {
  			err = -EINVAL;
  			goto out_free;
  		}
  
  		/* Save current address so we can work with it */
  		memcpy(&to, sa_addr, af->sockaddr_len);
  
  		err = sctp_verify_addr(sk, &to, af->sockaddr_len);
  		if (err)
  			goto out_free;
  
  		/* Make sure the destination port is correctly set
  		 * in all addresses.
  		 */
  		if (asoc && asoc->peer.port && asoc->peer.port != port)
  			goto out_free;
  
  
  		/* Check if there already is a matching association on the
  		 * endpoint (other than the one created here).
  		 */
  		asoc2 = sctp_endpoint_lookup_assoc(ep, &to, &transport);
  		if (asoc2 && asoc2 != asoc) {
  			if (asoc2->state >= SCTP_STATE_ESTABLISHED)
  				err = -EISCONN;
  			else
  				err = -EALREADY;
  			goto out_free;
  		}
  
  		/* If we could not find a matching association on the endpoint,
  		 * make sure that there is no peeled-off association matching
  		 * the peer address even on another socket.
  		 */
  		if (sctp_endpoint_is_peeled_off(ep, &to)) {
  			err = -EADDRNOTAVAIL;
  			goto out_free;
  		}
  
  		if (!asoc) {
  			/* If a bind() or sctp_bindx() is not called prior to
  			 * an sctp_connectx() call, the system picks an
  			 * ephemeral port and will choose an address set
  			 * equivalent to binding with a wildcard address.
  			 */
  			if (!ep->base.bind_addr.port) {
  				if (sctp_autobind(sk)) {
  					err = -EAGAIN;
  					goto out_free;
  				}
  			} else {
  				/*
  				 * If an unprivileged user inherits a 1-many
  				 * style socket with open associations on a
  				 * privileged port, it MAY be permitted to
  				 * accept new associations, but it SHOULD NOT
  				 * be permitted to open new associations.
  				 */
  				if (ep->base.bind_addr.port < PROT_SOCK &&
  				    !capable(CAP_NET_BIND_SERVICE)) {
  					err = -EACCES;
  					goto out_free;
  				}
  			}
  
  			scope = sctp_scope(&to);
  			asoc = sctp_association_new(ep, sk, scope, GFP_KERNEL);
  			if (!asoc) {
  				err = -ENOMEM;
  				goto out_free;
  			}
  
  			err = sctp_assoc_set_bind_addr_from_ep(asoc, scope,
  							      GFP_KERNEL);
  			if (err < 0) {
  				goto out_free;
  			}
  
  		}
  
  		/* Prime the peer's transport structures.  */
  		transport = sctp_assoc_add_peer(asoc, &to, GFP_KERNEL,
  						SCTP_UNKNOWN);
  		if (!transport) {
  			err = -ENOMEM;
  			goto out_free;
  		}
  
  		addrcnt++;
  		addr_buf += af->sockaddr_len;
  		walk_size += af->sockaddr_len;
  	}
  
  	/* In case the user of sctp_connectx() wants an association
  	 * id back, assign one now.
  	 */
  	if (assoc_id) {
  		err = sctp_assoc_set_id(asoc, GFP_KERNEL);
  		if (err < 0)
  			goto out_free;
  	}
  
  	err = sctp_primitive_ASSOCIATE(asoc, NULL);
  	if (err < 0) {
  		goto out_free;
  	}
  
  	/* Initialize sk's dport and daddr for getpeername() */
  	inet_sk(sk)->inet_dport = htons(asoc->peer.port);
  	af = sctp_get_af_specific(sa_addr->sa.sa_family);
  	af->to_sk_daddr(sa_addr, sk);
  	sk->sk_err = 0;
  
  	/* in-kernel sockets don't generally have a file allocated to them
  	 * if all they do is call sock_create_kern().
  	 */
  	if (sk->sk_socket->file)
  		f_flags = sk->sk_socket->file->f_flags;
  
  	timeo = sock_sndtimeo(sk, f_flags & O_NONBLOCK);
  
  	err = sctp_wait_for_connect(asoc, &timeo);
  	if ((err == 0 || err == -EINPROGRESS) && assoc_id)
  		*assoc_id = asoc->assoc_id;
  
  	/* Don't free association on exit. */
  	asoc = NULL;
  
  out_free:
  
  	SCTP_DEBUG_PRINTK("About to exit __sctp_connect() free asoc: %p"
  			  " kaddrs: %p err: %d\n",
  			  asoc, kaddrs, err);
  	if (asoc)
  		sctp_association_free(asoc);
  	return err;
  }
  
  /* Helper for tunneling sctp_connectx() requests through sctp_setsockopt()
   *
   * API 8.9
   * int sctp_connectx(int sd, struct sockaddr *addrs, int addrcnt,
   * 			sctp_assoc_t *asoc);
   *
   * If sd is an IPv4 socket, the addresses passed must be IPv4 addresses.
   * If the sd is an IPv6 socket, the addresses passed can either be IPv4
   * or IPv6 addresses.
   *
   * A single address may be specified as INADDR_ANY or IN6ADDR_ANY, see
   * Section 3.1.2 for this usage.
   *
   * addrs is a pointer to an array of one or more socket addresses. Each
   * address is contained in its appropriate structure (i.e. struct
   * sockaddr_in or struct sockaddr_in6) the family of the address type
   * must be used to distengish the address length (note that this
   * representation is termed a "packed array" of addresses). The caller
   * specifies the number of addresses in the array with addrcnt.
   *
   * On success, sctp_connectx() returns 0. It also sets the assoc_id to
   * the association id of the new association.  On failure, sctp_connectx()
   * returns -1, and sets errno to the appropriate error code.  The assoc_id
   * is not touched by the kernel.
   *
   * For SCTP, the port given in each socket address must be the same, or
   * sctp_connectx() will fail, setting errno to EINVAL.
   *
   * An application can use sctp_connectx to initiate an association with
   * an endpoint that is multi-homed.  Much like sctp_bindx() this call
   * allows a caller to specify multiple addresses at which a peer can be
   * reached.  The way the SCTP stack uses the list of addresses to set up
   * the association is implementation dependant.  This function only
   * specifies that the stack will try to make use of all the addresses in
   * the list when needed.
   *
   * Note that the list of addresses passed in is only used for setting up
   * the association.  It does not necessarily equal the set of addresses
   * the peer uses for the resulting association.  If the caller wants to
   * find out the set of peer addresses, it must use sctp_getpaddrs() to
   * retrieve them after the association has been set up.
   *
   * Basically do nothing but copying the addresses from user to kernel
   * land and invoking either sctp_connectx(). This is used for tunneling
   * the sctp_connectx() request through sctp_setsockopt() from userspace.
   *
   * We don't use copy_from_user() for optimization: we first do the
   * sanity checks (buffer size -fast- and access check-healthy
   * pointer); if all of those succeed, then we can alloc the memory
   * (expensive operation) needed to copy the data to kernel. Then we do
   * the copying without checking the user space area
   * (__copy_from_user()).
   *
   * On exit there is no need to do sockfd_put(), sys_setsockopt() does
   * it.
   *
   * sk        The sk of the socket
   * addrs     The pointer to the addresses in user land
   * addrssize Size of the addrs buffer
   *
   * Returns >=0 if ok, <0 errno code on error.
   */
  SCTP_STATIC int __sctp_setsockopt_connectx(struct sock* sk,
  				      struct sockaddr __user *addrs,
  				      int addrs_size,
  				      sctp_assoc_t *assoc_id)
  {
  	int err = 0;
  	struct sockaddr *kaddrs;
  
  	SCTP_DEBUG_PRINTK("%s - sk %p addrs %p addrs_size %d\n",
  			  __func__, sk, addrs, addrs_size);
  
  	if (unlikely(addrs_size <= 0))
  		return -EINVAL;
  
  	/* Check the user passed a healthy pointer.  */
  	if (unlikely(!access_ok(VERIFY_READ, addrs, addrs_size)))
  		return -EFAULT;
  
  	/* Alloc space for the address array in kernel memory.  */
  	kaddrs = kmalloc(addrs_size, GFP_KERNEL);
  	if (unlikely(!kaddrs))
  		return -ENOMEM;
  
  	if (__copy_from_user(kaddrs, addrs, addrs_size)) {
  		err = -EFAULT;
  	} else {
  		err = __sctp_connect(sk, kaddrs, addrs_size, assoc_id);
  	}
  
  	kfree(kaddrs);
  
  	return err;
  }
  
  /*
   * This is an older interface.  It's kept for backward compatibility
   * to the option that doesn't provide association id.
   */
  SCTP_STATIC int sctp_setsockopt_connectx_old(struct sock* sk,
  				      struct sockaddr __user *addrs,
  				      int addrs_size)
  {
  	return __sctp_setsockopt_connectx(sk, addrs, addrs_size, NULL);
  }
  
  /*
   * New interface for the API.  The since the API is done with a socket
   * option, to make it simple we feed back the association id is as a return
   * indication to the call.  Error is always negative and association id is
   * always positive.
   */
  SCTP_STATIC int sctp_setsockopt_connectx(struct sock* sk,
  				      struct sockaddr __user *addrs,
  				      int addrs_size)
  {
  	sctp_assoc_t assoc_id = 0;
  	int err = 0;
  
  	err = __sctp_setsockopt_connectx(sk, addrs, addrs_size, &assoc_id);
  
  	if (err)
  		return err;
  	else
  		return assoc_id;
  }
  
  /*
   * New (hopefully final) interface for the API.
   * We use the sctp_getaddrs_old structure so that use-space library
   * can avoid any unnecessary allocations.   The only defferent part
   * is that we store the actual length of the address buffer into the
   * addrs_num structure member.  That way we can re-use the existing
   * code.
   */
  SCTP_STATIC int sctp_getsockopt_connectx3(struct sock* sk, int len,
  					char __user *optval,
  					int __user *optlen)
  {
  	struct sctp_getaddrs_old param;
  	sctp_assoc_t assoc_id = 0;
  	int err = 0;
  
  	if (len < sizeof(param))
  		return -EINVAL;
  
  	if (copy_from_user(&param, optval, sizeof(param)))
  		return -EFAULT;
  
  	err = __sctp_setsockopt_connectx(sk,
  			(struct sockaddr __user *)param.addrs,
  			param.addr_num, &assoc_id);
  
  	if (err == 0 || err == -EINPROGRESS) {
  		if (copy_to_user(optval, &assoc_id, sizeof(assoc_id)))
  			return -EFAULT;
  		if (put_user(sizeof(assoc_id), optlen))
  			return -EFAULT;
  	}
  
  	return err;
  }
  
  /* API 3.1.4 close() - UDP Style Syntax
   * Applications use close() to perform graceful shutdown (as described in
   * Section 10.1 of [SCTP]) on ALL the associations currently represented
   * by a UDP-style socket.
   *
   * The syntax is
   *
   *   ret = close(int sd);
   *
   *   sd      - the socket descriptor of the associations to be closed.
   *
   * To gracefully shutdown a specific association represented by the
   * UDP-style socket, an application should use the sendmsg() call,
   * passing no user data, but including the appropriate flag in the
   * ancillary data (see Section xxxx).
   *
   * If sd in the close() call is a branched-off socket representing only
   * one association, the shutdown is performed on that association only.
   *
   * 4.1.6 close() - TCP Style Syntax
   *
   * Applications use close() to gracefully close down an association.
   *
   * The syntax is:
   *
   *    int close(int sd);
   *
   *      sd      - the socket descriptor of the association to be closed.
   *
   * After an application calls close() on a socket descriptor, no further
   * socket operations will succeed on that descriptor.
   *
   * API 7.1.4 SO_LINGER
   *
   * An application using the TCP-style socket can use this option to
   * perform the SCTP ABORT primitive.  The linger option structure is:
   *
   *  struct  linger {
   *     int     l_onoff;                // option on/off
   *     int     l_linger;               // linger time
   * };
   *
   * To enable the option, set l_onoff to 1.  If the l_linger value is set
   * to 0, calling close() is the same as the ABORT primitive.  If the
   * value is set to a negative value, the setsockopt() call will return
   * an error.  If the value is set to a positive value linger_time, the
   * close() can be blocked for at most linger_time ms.  If the graceful
   * shutdown phase does not finish during this period, close() will
   * return but the graceful shutdown phase continues in the system.
   */
  SCTP_STATIC void sctp_close(struct sock *sk, long timeout)
  {
  	struct sctp_endpoint *ep;
  	struct sctp_association *asoc;
  	struct list_head *pos, *temp;
  
  	SCTP_DEBUG_PRINTK("sctp_close(sk: 0x%p, timeout:%ld)\n", sk, timeout);
  
  	sctp_lock_sock(sk);
  	sk->sk_shutdown = SHUTDOWN_MASK;
  	sk->sk_state = SCTP_SS_CLOSING;
  
  	ep = sctp_sk(sk)->ep;
  
  	/* Walk all associations on an endpoint.  */
  	list_for_each_safe(pos, temp, &ep->asocs) {
  		asoc = list_entry(pos, struct sctp_association, asocs);
  
  		if (sctp_style(sk, TCP)) {
  			/* A closed association can still be in the list if
  			 * it belongs to a TCP-style listening socket that is
  			 * not yet accepted. If so, free it. If not, send an
  			 * ABORT or SHUTDOWN based on the linger options.
  			 */
  			if (sctp_state(asoc, CLOSED)) {
  				sctp_unhash_established(asoc);
  				sctp_association_free(asoc);
  				continue;
  			}
  		}
  
  		if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
  			struct sctp_chunk *chunk;
  
  			chunk = sctp_make_abort_user(asoc, NULL, 0);
  			if (chunk)
  				sctp_primitive_ABORT(asoc, chunk);
  		} else
  			sctp_primitive_SHUTDOWN(asoc, NULL);
  	}
  
  	/* Clean up any skbs sitting on the receive queue.  */
  	sctp_queue_purge_ulpevents(&sk->sk_receive_queue);
  	sctp_queue_purge_ulpevents(&sctp_sk(sk)->pd_lobby);
  
  	/* On a TCP-style socket, block for at most linger_time if set. */
  	if (sctp_style(sk, TCP) && timeout)
  		sctp_wait_for_close(sk, timeout);
  
  	/* This will run the backlog queue.  */
  	sctp_release_sock(sk);
  
  	/* Supposedly, no process has access to the socket, but
  	 * the net layers still may.
  	 */
  	sctp_local_bh_disable();
  	sctp_bh_lock_sock(sk);
  
  	/* Hold the sock, since sk_common_release() will put sock_put()
  	 * and we have just a little more cleanup.
  	 */
  	sock_hold(sk);
  	sk_common_release(sk);
  
  	sctp_bh_unlock_sock(sk);
  	sctp_local_bh_enable();
  
  	sock_put(sk);
  
  	SCTP_DBG_OBJCNT_DEC(sock);
  }
  
  /* Handle EPIPE error. */
  static int sctp_error(struct sock *sk, int flags, int err)
  {
  	if (err == -EPIPE)
  		err = sock_error(sk) ? : -EPIPE;
  	if (err == -EPIPE && !(flags & MSG_NOSIGNAL))
  		send_sig(SIGPIPE, current, 0);
  	return err;
  }
  
  /* API 3.1.3 sendmsg() - UDP Style Syntax
   *
   * An application uses sendmsg() and recvmsg() calls to transmit data to
   * and receive data from its peer.
   *
   *  ssize_t sendmsg(int socket, const struct msghdr *message,
   *                  int flags);
   *
   *  socket  - the socket descriptor of the endpoint.
   *  message - pointer to the msghdr structure which contains a single
   *            user message and possibly some ancillary data.
   *
   *            See Section 5 for complete description of the data
   *            structures.
   *
   *  flags   - flags sent or received with the user message, see Section
   *            5 for complete description of the flags.
   *
   * Note:  This function could use a rewrite especially when explicit
   * connect support comes in.
   */
  /* BUG:  We do not implement the equivalent of sk_stream_wait_memory(). */
  
  SCTP_STATIC int sctp_msghdr_parse(const struct msghdr *, sctp_cmsgs_t *);
  
  SCTP_STATIC int sctp_sendmsg(struct kiocb *iocb, struct sock *sk,
  			     struct msghdr *msg, size_t msg_len)
  {
  	struct sctp_sock *sp;
  	struct sctp_endpoint *ep;
  	struct sctp_association *new_asoc=NULL, *asoc=NULL;
  	struct sctp_transport *transport, *chunk_tp;
  	struct sctp_chunk *chunk;
  	union sctp_addr to;
  	struct sockaddr *msg_name = NULL;
  	struct sctp_sndrcvinfo default_sinfo = { 0 };
  	struct sctp_sndrcvinfo *sinfo;
  	struct sctp_initmsg *sinit;
  	sctp_assoc_t associd = 0;
  	sctp_cmsgs_t cmsgs = { NULL };
  	int err;
  	sctp_scope_t scope;
  	long timeo;
  	__u16 sinfo_flags = 0;
  	struct sctp_datamsg *datamsg;
  	int msg_flags = msg->msg_flags;
  
  	SCTP_DEBUG_PRINTK("sctp_sendmsg(sk: %p, msg: %p, msg_len: %zu)\n",
  			  sk, msg, msg_len);
  
  	err = 0;
  	sp = sctp_sk(sk);
  	ep = sp->ep;
  
  	SCTP_DEBUG_PRINTK("Using endpoint: %p.\n", ep);
  
  	/* We cannot send a message over a TCP-style listening socket. */
  	if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING)) {
  		err = -EPIPE;
  		goto out_nounlock;
  	}
  
  	/* Parse out the SCTP CMSGs.  */
  	err = sctp_msghdr_parse(msg, &cmsgs);
  
  	if (err) {
  		SCTP_DEBUG_PRINTK("msghdr parse err = %x\n", err);
  		goto out_nounlock;
  	}
  
  	/* Fetch the destination address for this packet.  This
  	 * address only selects the association--it is not necessarily
  	 * the address we will send to.
  	 * For a peeled-off socket, msg_name is ignored.
  	 */
  	if (!sctp_style(sk, UDP_HIGH_BANDWIDTH) && msg->msg_name) {
  		int msg_namelen = msg->msg_namelen;
  
  		err = sctp_verify_addr(sk, (union sctp_addr *)msg->msg_name,
  				       msg_namelen);
  		if (err)
  			return err;
  
  		if (msg_namelen > sizeof(to))
  			msg_namelen = sizeof(to);
  		memcpy(&to, msg->msg_name, msg_namelen);
  		msg_name = msg->msg_name;
  	}
  
  	sinfo = cmsgs.info;
  	sinit = cmsgs.init;
  
  	/* Did the user specify SNDRCVINFO?  */
  	if (sinfo) {
  		sinfo_flags = sinfo->sinfo_flags;
  		associd = sinfo->sinfo_assoc_id;
  	}
  
  	SCTP_DEBUG_PRINTK("msg_len: %zu, sinfo_flags: 0x%x\n",
  			  msg_len, sinfo_flags);
  
  	/* SCTP_EOF or SCTP_ABORT cannot be set on a TCP-style socket. */
  	if (sctp_style(sk, TCP) && (sinfo_flags & (SCTP_EOF | SCTP_ABORT))) {
  		err = -EINVAL;
  		goto out_nounlock;
  	}
  
  	/* If SCTP_EOF is set, no data can be sent. Disallow sending zero
  	 * length messages when SCTP_EOF|SCTP_ABORT is not set.
  	 * If SCTP_ABORT is set, the message length could be non zero with
  	 * the msg_iov set to the user abort reason.
  	 */
  	if (((sinfo_flags & SCTP_EOF) && (msg_len > 0)) ||
  	    (!(sinfo_flags & (SCTP_EOF|SCTP_ABORT)) && (msg_len == 0))) {
  		err = -EINVAL;
  		goto out_nounlock;
  	}
  
  	/* If SCTP_ADDR_OVER is set, there must be an address
  	 * specified in msg_name.
  	 */
  	if ((sinfo_flags & SCTP_ADDR_OVER) && (!msg->msg_name)) {
  		err = -EINVAL;
  		goto out_nounlock;
  	}
  
  	transport = NULL;
  
  	SCTP_DEBUG_PRINTK("About to look up association.\n");
  
  	sctp_lock_sock(sk);
  
  	/* If a msg_name has been specified, assume this is to be used.  */
  	if (msg_name) {
  		/* Look for a matching association on the endpoint. */
  		asoc = sctp_endpoint_lookup_assoc(ep, &to, &transport);
  		if (!asoc) {
  			/* If we could not find a matching association on the
  			 * endpoint, make sure that it is not a TCP-style
  			 * socket that already has an association or there is
  			 * no peeled-off association on another socket.
  			 */
  			if ((sctp_style(sk, TCP) &&
  			     sctp_sstate(sk, ESTABLISHED)) ||
  			    sctp_endpoint_is_peeled_off(ep, &to)) {
  				err = -EADDRNOTAVAIL;
  				goto out_unlock;
  			}
  		}
  	} else {
  		asoc = sctp_id2assoc(sk, associd);
  		if (!asoc) {
  			err = -EPIPE;
  			goto out_unlock;
  		}
  	}
  
  	if (asoc) {
  		SCTP_DEBUG_PRINTK("Just looked up association: %p.\n", asoc);
  
  		/* We cannot send a message on a TCP-style SCTP_SS_ESTABLISHED
  		 * socket that has an association in CLOSED state. This can
  		 * happen when an accepted socket has an association that is
  		 * already CLOSED.
  		 */
  		if (sctp_state(asoc, CLOSED) && sctp_style(sk, TCP)) {
  			err = -EPIPE;
  			goto out_unlock;
  		}
  
  		if (sinfo_flags & SCTP_EOF) {
  			SCTP_DEBUG_PRINTK("Shutting down association: %p\n",
  					  asoc);
  			sctp_primitive_SHUTDOWN(asoc, NULL);
  			err = 0;
  			goto out_unlock;
  		}
  		if (sinfo_flags & SCTP_ABORT) {
  
  			chunk = sctp_make_abort_user(asoc, msg, msg_len);
  			if (!chunk) {
  				err = -ENOMEM;
  				goto out_unlock;
  			}
  
  			SCTP_DEBUG_PRINTK("Aborting association: %p\n", asoc);
  			sctp_primitive_ABORT(asoc, chunk);
  			err = 0;
  			goto out_unlock;
  		}
  	}
  
  	/* Do we need to create the association?  */
  	if (!asoc) {
  		SCTP_DEBUG_PRINTK("There is no association yet.\n");
  
  		if (sinfo_flags & (SCTP_EOF | SCTP_ABORT)) {
  			err = -EINVAL;
  			goto out_unlock;
  		}
  
  		/* Check for invalid stream against the stream counts,
  		 * either the default or the user specified stream counts.
  		 */
  		if (sinfo) {
  			if (!sinit || (sinit && !sinit->sinit_num_ostreams)) {
  				/* Check against the defaults. */
  				if (sinfo->sinfo_stream >=
  				    sp->initmsg.sinit_num_ostreams) {
  					err = -EINVAL;
  					goto out_unlock;
  				}
  			} else {
  				/* Check against the requested.  */
  				if (sinfo->sinfo_stream >=
  				    sinit->sinit_num_ostreams) {
  					err = -EINVAL;
  					goto out_unlock;
  				}
  			}
  		}
  
  		/*
  		 * API 3.1.2 bind() - UDP Style Syntax
  		 * If a bind() or sctp_bindx() is not called prior to a
  		 * sendmsg() call that initiates a new association, the
  		 * system picks an ephemeral port and will choose an address
  		 * set equivalent to binding with a wildcard address.
  		 */
  		if (!ep->base.bind_addr.port) {
  			if (sctp_autobind(sk)) {
  				err = -EAGAIN;
  				goto out_unlock;
  			}
  		} else {
  			/*
  			 * If an unprivileged user inherits a one-to-many
  			 * style socket with open associations on a privileged
  			 * port, it MAY be permitted to accept new associations,
  			 * but it SHOULD NOT be permitted to open new
  			 * associations.
  			 */
  			if (ep->base.bind_addr.port < PROT_SOCK &&
  			    !capable(CAP_NET_BIND_SERVICE)) {
  				err = -EACCES;
  				goto out_unlock;
  			}
  		}
  
  		scope = sctp_scope(&to);
  		new_asoc = sctp_association_new(ep, sk, scope, GFP_KERNEL);
  		if (!new_asoc) {
  			err = -ENOMEM;
  			goto out_unlock;
  		}
  		asoc = new_asoc;
  		err = sctp_assoc_set_bind_addr_from_ep(asoc, scope, GFP_KERNEL);
  		if (err < 0) {
  			err = -ENOMEM;
  			goto out_free;
  		}
  
  		/* If the SCTP_INIT ancillary data is specified, set all
  		 * the association init values accordingly.
  		 */
  		if (sinit) {
  			if (sinit->sinit_num_ostreams) {
  				asoc->c.sinit_num_ostreams =
  					sinit->sinit_num_ostreams;
  			}
  			if (sinit->sinit_max_instreams) {
  				asoc->c.sinit_max_instreams =
  					sinit->sinit_max_instreams;
  			}
  			if (sinit->sinit_max_attempts) {
  				asoc->max_init_attempts
  					= sinit->sinit_max_attempts;
  			}
  			if (sinit->sinit_max_init_timeo) {
  				asoc->max_init_timeo =
  				 msecs_to_jiffies(sinit->sinit_max_init_timeo);
  			}
  		}
  
  		/* Prime the peer's transport structures.  */
  		transport = sctp_assoc_add_peer(asoc, &to, GFP_KERNEL, SCTP_UNKNOWN);
  		if (!transport) {
  			err = -ENOMEM;
  			goto out_free;
  		}
  	}
  
  	/* ASSERT: we have a valid association at this point.  */
  	SCTP_DEBUG_PRINTK("We have a valid association.\n");
  
  	if (!sinfo) {
  		/* If the user didn't specify SNDRCVINFO, make up one with
  		 * some defaults.
  		 */
  		default_sinfo.sinfo_stream = asoc->default_stream;
  		default_sinfo.sinfo_flags = asoc->default_flags;
  		default_sinfo.sinfo_ppid = asoc->default_ppid;
  		default_sinfo.sinfo_context = asoc->default_context;
  		default_sinfo.sinfo_timetolive = asoc->default_timetolive;
  		default_sinfo.sinfo_assoc_id = sctp_assoc2id(asoc);
  		sinfo = &default_sinfo;
  	}
  
  	/* API 7.1.7, the sndbuf size per association bounds the
  	 * maximum size of data that can be sent in a single send call.
  	 */
  	if (msg_len > sk->sk_sndbuf) {
  		err = -EMSGSIZE;
  		goto out_free;
  	}
  
  	if (asoc->pmtu_pending)
  		sctp_assoc_pending_pmtu(asoc);
  
  	/* If fragmentation is disabled and the message length exceeds the
  	 * association fragmentation point, return EMSGSIZE.  The I-D
  	 * does not specify what this error is, but this looks like
  	 * a great fit.
  	 */
  	if (sctp_sk(sk)->disable_fragments && (msg_len > asoc->frag_point)) {
  		err = -EMSGSIZE;
  		goto out_free;
  	}
  
  	if (sinfo) {
  		/* Check for invalid stream. */
  		if (sinfo->sinfo_stream >= asoc->c.sinit_num_ostreams) {
  			err = -EINVAL;
  			goto out_free;
  		}
  	}
  
  	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
  	if (!sctp_wspace(asoc)) {
  		err = sctp_wait_for_sndbuf(asoc, &timeo, msg_len);
  		if (err)
  			goto out_free;
  	}
  
  	/* If an address is passed with the sendto/sendmsg call, it is used
  	 * to override the primary destination address in the TCP model, or
  	 * when SCTP_ADDR_OVER flag is set in the UDP model.
  	 */
  	if ((sctp_style(sk, TCP) && msg_name) ||
  	    (sinfo_flags & SCTP_ADDR_OVER)) {
  		chunk_tp = sctp_assoc_lookup_paddr(asoc, &to);
  		if (!chunk_tp) {
  			err = -EINVAL;
  			goto out_free;
  		}
  	} else
  		chunk_tp = NULL;
  
  	/* Auto-connect, if we aren't connected already. */
  	if (sctp_state(asoc, CLOSED)) {
  		err = sctp_primitive_ASSOCIATE(asoc, NULL);
  		if (err < 0)
  			goto out_free;
  		SCTP_DEBUG_PRINTK("We associated primitively.\n");
  	}
  
  	/* Break the message into multiple chunks of maximum size. */
  	datamsg = sctp_datamsg_from_user(asoc, sinfo, msg, msg_len);
  	if (!datamsg) {
  		err = -ENOMEM;
  		goto out_free;
  	}
  
  	/* Now send the (possibly) fragmented message. */
  	list_for_each_entry(chunk, &datamsg->chunks, frag_list) {
  		sctp_chunk_hold(chunk);
  
  		/* Do accounting for the write space.  */
  		sctp_set_owner_w(chunk);
  
  		chunk->transport = chunk_tp;
  	}
  
  	/* Send it to the lower layers.  Note:  all chunks
  	 * must either fail or succeed.   The lower layer
  	 * works that way today.  Keep it that way or this
  	 * breaks.
  	 */
  	err = sctp_primitive_SEND(asoc, datamsg);
  	/* Did the lower layer accept the chunk? */
  	if (err)
  		sctp_datamsg_free(datamsg);
  	else
  		sctp_datamsg_put(datamsg);
  
  	SCTP_DEBUG_PRINTK("We sent primitively.\n");
  
  	if (err)
  		goto out_free;
  	else
  		err = msg_len;
  
  	/* If we are already past ASSOCIATE, the lower
  	 * layers are responsible for association cleanup.
  	 */
  	goto out_unlock;
  
  out_free:
  	if (new_asoc)
  		sctp_association_free(asoc);
  out_unlock:
  	sctp_release_sock(sk);
  
  out_nounlock:
  	return sctp_error(sk, msg_flags, err);
  
  #if 0
  do_sock_err:
  	if (msg_len)
  		err = msg_len;
  	else
  		err = sock_error(sk);
  	goto out;
  
  do_interrupted:
  	if (msg_len)
  		err = msg_len;
  	goto out;
  #endif /* 0 */
  }
  
  /* This is an extended version of skb_pull() that removes the data from the
   * start of a skb even when data is spread across the list of skb's in the
   * frag_list. len specifies the total amount of data that needs to be removed.
   * when 'len' bytes could be removed from the skb, it returns 0.
   * If 'len' exceeds the total skb length,  it returns the no. of bytes that
   * could not be removed.
   */
  static int sctp_skb_pull(struct sk_buff *skb, int len)
  {
  	struct sk_buff *list;
  	int skb_len = skb_headlen(skb);
  	int rlen;
  
  	if (len <= skb_len) {
  		__skb_pull(skb, len);
  		return 0;
  	}
  	len -= skb_len;
  	__skb_pull(skb, skb_len);
  
  	skb_walk_frags(skb, list) {
  		rlen = sctp_skb_pull(list, len);
  		skb->len -= (len-rlen);
  		skb->data_len -= (len-rlen);
  
  		if (!rlen)
  			return 0;
  
  		len = rlen;
  	}
  
  	return len;
  }
  
  /* API 3.1.3  recvmsg() - UDP Style Syntax
   *
   *  ssize_t recvmsg(int socket, struct msghdr *message,
   *                    int flags);
   *
   *  socket  - the socket descriptor of the endpoint.
   *  message - pointer to the msghdr structure which contains a single
   *            user message and possibly some ancillary data.
   *
   *            See Section 5 for complete description of the data
   *            structures.
   *
   *  flags   - flags sent or received with the user message, see Section
   *            5 for complete description of the flags.
   */
  static struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int, int *);
  
  SCTP_STATIC int sctp_recvmsg(struct kiocb *iocb, struct sock *sk,
  			     struct msghdr *msg, size_t len, int noblock,
  			     int flags, int *addr_len)
  {
  	struct sctp_ulpevent *event = NULL;
  	struct sctp_sock *sp = sctp_sk(sk);
  	struct sk_buff *skb;
  	int copied;
  	int err = 0;
  	int skb_len;
  
  	SCTP_DEBUG_PRINTK("sctp_recvmsg(%s: %p, %s: %p, %s: %zd, %s: %d, %s: "
  			  "0x%x, %s: %p)\n", "sk", sk, "msghdr", msg,
  			  "len", len, "knoblauch", noblock,
  			  "flags", flags, "addr_len", addr_len);
  
  	sctp_lock_sock(sk);
  
  	if (sctp_style(sk, TCP) && !sctp_sstate(sk, ESTABLISHED)) {
  		err = -ENOTCONN;
  		goto out;
  	}
  
  	skb = sctp_skb_recv_datagram(sk, flags, noblock, &err);
  	if (!skb)
  		goto out;
  
  	/* Get the total length of the skb including any skb's in the
  	 * frag_list.
  	 */
  	skb_len = skb->len;
  
  	copied = skb_len;
  	if (copied > len)
  		copied = len;
  
  	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
  
  	event = sctp_skb2event(skb);
  
  	if (err)
  		goto out_free;
  
  	sock_recv_ts_and_drops(msg, sk, skb);
  	if (sctp_ulpevent_is_notification(event)) {
  		msg->msg_flags |= MSG_NOTIFICATION;
  		sp->pf->event_msgname(event, msg->msg_name, addr_len);
  	} else {
  		sp->pf->skb_msgname(skb, msg->msg_name, addr_len);
  	}
  
  	/* Check if we allow SCTP_SNDRCVINFO. */
  	if (sp->subscribe.sctp_data_io_event)
  		sctp_ulpevent_read_sndrcvinfo(event, msg);
  #if 0
  	/* FIXME: we should be calling IP/IPv6 layers.  */
  	if (sk->sk_protinfo.af_inet.cmsg_flags)
  		ip_cmsg_recv(msg, skb);
  #endif
  
  	err = copied;
  
  	/* If skb's length exceeds the user's buffer, update the skb and
  	 * push it back to the receive_queue so that the next call to
  	 * recvmsg() will return the remaining data. Don't set MSG_EOR.
  	 */
  	if (skb_len > copied) {
  		msg->msg_flags &= ~MSG_EOR;
  		if (flags & MSG_PEEK)
  			goto out_free;
  		sctp_skb_pull(skb, copied);
  		skb_queue_head(&sk->sk_receive_queue, skb);
  
  		/* When only partial message is copied to the user, increase
  		 * rwnd by that amount. If all the data in the skb is read,
  		 * rwnd is updated when the event is freed.
  		 */
  		if (!sctp_ulpevent_is_notification(event))
  			sctp_assoc_rwnd_increase(event->asoc, copied);
  		goto out;
  	} else if ((event->msg_flags & MSG_NOTIFICATION) ||
  		   (event->msg_flags & MSG_EOR))
  		msg->msg_flags |= MSG_EOR;
  	else
  		msg->msg_flags &= ~MSG_EOR;
  
  out_free:
  	if (flags & MSG_PEEK) {
  		/* Release the skb reference acquired after peeking the skb in
  		 * sctp_skb_recv_datagram().
  		 */
  		kfree_skb(skb);
  	} else {
  		/* Free the event which includes releasing the reference to
  		 * the owner of the skb, freeing the skb and updating the
  		 * rwnd.
  		 */
  		sctp_ulpevent_free(event);
  	}
  out:
  	sctp_release_sock(sk);
  	return err;
  }
  
  /* 7.1.12 Enable/Disable message fragmentation (SCTP_DISABLE_FRAGMENTS)
   *
   * This option is a on/off flag.  If enabled no SCTP message
   * fragmentation will be performed.  Instead if a message being sent
   * exceeds the current PMTU size, the message will NOT be sent and
   * instead a error will be indicated to the user.
   */
  static int sctp_setsockopt_disable_fragments(struct sock *sk,
  					     char __user *optval,
  					     unsigned int optlen)
  {
  	int val;
  
  	if (optlen < sizeof(int))
  		return -EINVAL;
  
  	if (get_user(val, (int __user *)optval))
  		return -EFAULT;
  
  	sctp_sk(sk)->disable_fragments = (val == 0) ? 0 : 1;
  
  	return 0;
  }
  
  static int sctp_setsockopt_events(struct sock *sk, char __user *optval,
  				  unsigned int optlen)
  {
  	if (optlen > sizeof(struct sctp_event_subscribe))
  		return -EINVAL;
  	if (copy_from_user(&sctp_sk(sk)->subscribe, optval, optlen))
  		return -EFAULT;
  	return 0;
  }
  
  /* 7.1.8 Automatic Close of associations (SCTP_AUTOCLOSE)
   *
   * This socket option is applicable to the UDP-style socket only.  When
   * set it will cause associations that are idle for more than the
   * specified number of seconds to automatically close.  An association
   * being idle is defined an association that has NOT sent or received
   * user data.  The special value of '0' indicates that no automatic
   * close of any associations should be performed.  The option expects an
   * integer defining the number of seconds of idle time before an
   * association is closed.
   */
  static int sctp_setsockopt_autoclose(struct sock *sk, char __user *optval,
  				     unsigned int optlen)
  {
  	struct sctp_sock *sp = sctp_sk(sk);
  
  	/* Applicable to UDP-style socket only */
  	if (sctp_style(sk, TCP))
  		return -EOPNOTSUPP;
  	if (optlen != sizeof(int))
  		return -EINVAL;
  	if (copy_from_user(&sp->autoclose, optval, optlen))
  		return -EFAULT;
  	/* make sure it won't exceed MAX_SCHEDULE_TIMEOUT */
  	sp->autoclose = min_t(long, sp->autoclose, MAX_SCHEDULE_TIMEOUT / HZ);
  
  	return 0;
  }
  
  /* 7.1.13 Peer Address Parameters (SCTP_PEER_ADDR_PARAMS)
   *
   * Applications can enable or disable heartbeats for any peer address of
   * an association, modify an address's heartbeat interval, force a
   * heartbeat to be sent immediately, and adjust the address's maximum
   * number of retransmissions sent before an address is considered
   * unreachable.  The following structure is used to access and modify an
   * address's parameters:
   *
   *  struct sctp_paddrparams {
   *     sctp_assoc_t            spp_assoc_id;
   *     struct sockaddr_storage spp_address;
   *     uint32_t                spp_hbinterval;
   *     uint16_t                spp_pathmaxrxt;
   *     uint32_t                spp_pathmtu;
   *     uint32_t                spp_sackdelay;
   *     uint32_t                spp_flags;
   * };
   *
   *   spp_assoc_id    - (one-to-many style socket) This is filled in the
   *                     application, and identifies the association for
   *                     this query.
   *   spp_address     - This specifies which address is of interest.
   *   spp_hbinterval  - This contains the value of the heartbeat interval,
   *                     in milliseconds.  If a  value of zero
   *                     is present in this field then no changes are to
   *                     be made to this parameter.
   *   spp_pathmaxrxt  - This contains the maximum number of
   *                     retransmissions before this address shall be
   *                     considered unreachable. If a  value of zero
   *                     is present in this field then no changes are to
   *                     be made to this parameter.
   *   spp_pathmtu     - When Path MTU discovery is disabled the value
   *                     specified here will be the "fixed" path mtu.
   *                     Note that if the spp_address field is empty
   *                     then all associations on this address will
   *                     have this fixed path mtu set upon them.
   *
   *   spp_sackdelay   - When delayed sack is enabled, this value specifies
   *                     the number of milliseconds that sacks will be delayed
   *                     for. This value will apply to all addresses of an
   *                     association if the spp_address field is empty. Note
   *                     also, that if delayed sack is enabled and this
   *                     value is set to 0, no change is made to the last
   *                     recorded delayed sack timer value.
   *
   *   spp_flags       - These flags are used to control various features
   *                     on an association. The flag field may contain
   *                     zero or more of the following options.
   *
   *                     SPP_HB_ENABLE  - Enable heartbeats on the
   *                     specified address. Note that if the address
   *                     field is empty all addresses for the association
   *                     have heartbeats enabled upon them.
   *
   *                     SPP_HB_DISABLE - Disable heartbeats on the
   *                     speicifed address. Note that if the address
   *                     field is empty all addresses for the association
   *                     will have their heartbeats disabled. Note also
   *                     that SPP_HB_ENABLE and SPP_HB_DISABLE are
   *                     mutually exclusive, only one of these two should
   *                     be specified. Enabling both fields will have
   *                     undetermined results.
   *
   *                     SPP_HB_DEMAND - Request a user initiated heartbeat
   *                     to be made immediately.
   *
   *                     SPP_HB_TIME_IS_ZERO - Specify's that the time for
   *                     heartbeat delayis to be set to the value of 0
   *                     milliseconds.
   *
   *                     SPP_PMTUD_ENABLE - This field will enable PMTU
   *                     discovery upon the specified address. Note that
   *                     if the address feild is empty then all addresses
   *                     on the association are effected.
   *
   *                     SPP_PMTUD_DISABLE - This field will disable PMTU
   *                     discovery upon the specified address. Note that
   *                     if the address feild is empty then all addresses
   *                     on the association are effected. Not also that
   *                     SPP_PMTUD_ENABLE and SPP_PMTUD_DISABLE are mutually
   *                     exclusive. Enabling both will have undetermined
   *                     results.
   *
   *                     SPP_SACKDELAY_ENABLE - Setting this flag turns
   *                     on delayed sack. The time specified in spp_sackdelay
   *                     is used to specify the sack delay for this address. Note
   *                     that if spp_address is empty then all addresses will
   *                     enable delayed sack and take on the sack delay
   *                     value specified in spp_sackdelay.
   *                     SPP_SACKDELAY_DISABLE - Setting this flag turns
   *                     off delayed sack. If the spp_address field is blank then
   *                     delayed sack is disabled for the entire association. Note
   *                     also that this field is mutually exclusive to
   *                     SPP_SACKDELAY_ENABLE, setting both will have undefined
   *                     results.
   */
  static int sctp_apply_peer_addr_params(struct sctp_paddrparams *params,
  				       struct sctp_transport   *trans,
  				       struct sctp_association *asoc,
  				       struct sctp_sock        *sp,
  				       int                      hb_change,
  				       int                      pmtud_change,
  				       int                      sackdelay_change)
  {
  	int error;
  
  	if (params->spp_flags & SPP_HB_DEMAND && trans) {
  		error = sctp_primitive_REQUESTHEARTBEAT (trans->asoc, trans);
  		if (error)
  			return error;
  	}
  
  	/* Note that unless the spp_flag is set to SPP_HB_ENABLE the value of
  	 * this field is ignored.  Note also that a value of zero indicates
  	 * the current setting should be left unchanged.
  	 */
  	if (params->spp_flags & SPP_HB_ENABLE) {
  
  		/* Re-zero the interval if the SPP_HB_TIME_IS_ZERO is
  		 * set.  This lets us use 0 value when this flag
  		 * is set.
  		 */
  		if (params->spp_flags & SPP_HB_TIME_IS_ZERO)
  			params->spp_hbinterval = 0;
  
  		if (params->spp_hbinterval ||
  		    (params->spp_flags & SPP_HB_TIME_IS_ZERO)) {
  			if (trans) {
  				trans->hbinterval =
  				    msecs_to_jiffies(params->spp_hbinterval);
  			} else if (asoc) {
  				asoc->hbinterval =
  				    msecs_to_jiffies(params->spp_hbinterval);
  			} else {
  				sp->hbinterval = params->spp_hbinterval;
  			}
  		}
  	}
  
  	if (hb_change) {
  		if (trans) {
  			trans->param_flags =
  				(trans->param_flags & ~SPP_HB) | hb_change;
  		} else if (asoc) {
  			asoc->param_flags =
  				(asoc->param_flags & ~SPP_HB) | hb_change;
  		} else {
  			sp->param_flags =
  				(sp->param_flags & ~SPP_HB) | hb_change;
  		}
  	}
  
  	/* When Path MTU discovery is disabled the value specified here will
  	 * be the "fixed" path mtu (i.e. the value of the spp_flags field must
  	 * include the flag SPP_PMTUD_DISABLE for this field to have any
  	 * effect).
  	 */
  	if ((params->spp_flags & SPP_PMTUD_DISABLE) && params->spp_pathmtu) {
  		if (trans) {
  			trans->pathmtu = params->spp_pathmtu;
  			sctp_assoc_sync_pmtu(asoc);
  		} else if (asoc) {
  			asoc->pathmtu = params->spp_pathmtu;
  			sctp_frag_point(asoc, params->spp_pathmtu);
  		} else {
  			sp->pathmtu = params->spp_pathmtu;
  		}
  	}
  
  	if (pmtud_change) {
  		if (trans) {
  			int update = (trans->param_flags & SPP_PMTUD_DISABLE) &&
  				(params->spp_flags & SPP_PMTUD_ENABLE);
  			trans->param_flags =
  				(trans->param_flags & ~SPP_PMTUD) | pmtud_change;
  			if (update) {
  				sctp_transport_pmtu(trans);
  				sctp_assoc_sync_pmtu(asoc);
  			}
  		} else if (asoc) {
  			asoc->param_flags =
  				(asoc->param_flags & ~SPP_PMTUD) | pmtud_change;
  		} else {
  			sp->param_flags =
  				(sp->param_flags & ~SPP_PMTUD) | pmtud_change;
  		}
  	}
  
  	/* Note that unless the spp_flag is set to SPP_SACKDELAY_ENABLE the
  	 * value of this field is ignored.  Note also that a value of zero
  	 * indicates the current setting should be left unchanged.
  	 */
  	if ((params->spp_flags & SPP_SACKDELAY_ENABLE) && params->spp_sackdelay) {
  		if (trans) {
  			trans->sackdelay =
  				msecs_to_jiffies(params->spp_sackdelay);
  		} else if (asoc) {
  			asoc->sackdelay =
  				msecs_to_jiffies(params->spp_sackdelay);
  		} else {
  			sp->sackdelay = params->spp_sackdelay;
  		}
  	}
  
  	if (sackdelay_change) {
  		if (trans) {
  			trans->param_flags =
  				(trans->param_flags & ~SPP_SACKDELAY) |
  				sackdelay_change;
  		} else if (asoc) {
  			asoc->param_flags =
  				(asoc->param_flags & ~SPP_SACKDELAY) |
  				sackdelay_change;
  		} else {
  			sp->param_flags =
  				(sp->param_flags & ~SPP_SACKDELAY) |
  				sackdelay_change;
  		}
  	}
  
  	/* Note that a value of zero indicates the current setting should be
  	   left unchanged.
  	 */
  	if (params->spp_pathmaxrxt) {
  		if (trans) {
  			trans->pathmaxrxt = params->spp_pathmaxrxt;
  		} else if (asoc) {
  			asoc->pathmaxrxt = params->spp_pathmaxrxt;
  		} else {
  			sp->pathmaxrxt = params->spp_pathmaxrxt;
  		}
  	}
  
  	return 0;
  }
  
  static int sctp_setsockopt_peer_addr_params(struct sock *sk,
  					    char __user *optval,
  					    unsigned int optlen)
  {
  	struct sctp_paddrparams  params;
  	struct sctp_transport   *trans = NULL;
  	struct sctp_association *asoc = NULL;
  	struct sctp_sock        *sp = sctp_sk(sk);
  	int error;
  	int hb_change, pmtud_change, sackdelay_change;
  
  	if (optlen != sizeof(struct sctp_paddrparams))
  		return - EINVAL;
  
  	if (copy_from_user(&params, optval, optlen))
  		return -EFAULT;
  
  	/* Validate flags and value parameters. */
  	hb_change        = params.spp_flags & SPP_HB;
  	pmtud_change     = params.spp_flags & SPP_PMTUD;
  	sackdelay_change = params.spp_flags & SPP_SACKDELAY;
  
  	if (hb_change        == SPP_HB ||
  	    pmtud_change     == SPP_PMTUD ||
  	    sackdelay_change == SPP_SACKDELAY ||
  	    params.spp_sackdelay > 500 ||
  	    (params.spp_pathmtu &&
  	     params.spp_pathmtu < SCTP_DEFAULT_MINSEGMENT))
  		return -EINVAL;
  
  	/* If an address other than INADDR_ANY is specified, and
  	 * no transport is found, then the request is invalid.
  	 */
  	if (!sctp_is_any(sk, ( union sctp_addr *)&params.spp_address)) {
  		trans = sctp_addr_id2transport(sk, &params.spp_address,
  					       params.spp_assoc_id);
  		if (!trans)
  			return -EINVAL;
  	}
  
  	/* Get association, if assoc_id != 0 and the socket is a one
  	 * to many style socket, and an association was not found, then
  	 * the id was invalid.
  	 */
  	asoc = sctp_id2assoc(sk, params.spp_assoc_id);
  	if (!asoc && params.spp_assoc_id && sctp_style(sk, UDP))
  		return -EINVAL;
  
  	/* Heartbeat demand can only be sent on a transport or
  	 * association, but not a socket.
  	 */
  	if (params.spp_flags & SPP_HB_DEMAND && !trans && !asoc)
  		return -EINVAL;
  
  	/* Process parameters. */
  	error = sctp_apply_peer_addr_params(&params, trans, asoc, sp,
  					    hb_change, pmtud_change,
  					    sackdelay_change);
  
  	if (error)
  		return error;
  
  	/* If changes are for association, also apply parameters to each
  	 * transport.
  	 */
  	if (!trans && asoc) {
  		list_for_each_entry(trans, &asoc->peer.transport_addr_list,
  				transports) {
  			sctp_apply_peer_addr_params(&params, trans, asoc, sp,
  						    hb_change, pmtud_change,
  						    sackdelay_change);
  		}
  	}
  
  	return 0;
  }
  
  /*
   * 7.1.23.  Get or set delayed ack timer (SCTP_DELAYED_SACK)
   *
   * This option will effect the way delayed acks are performed.  This
   * option allows you to get or set the delayed ack time, in
   * milliseconds.  It also allows changing the delayed ack frequency.
   * Changing the frequency to 1 disables the delayed sack algorithm.  If
   * the assoc_id is 0, then this sets or gets the endpoints default
   * values.  If the assoc_id field is non-zero, then the set or get
   * effects the specified association for the one to many model (the
   * assoc_id field is ignored by the one to one model).  Note that if
   * sack_delay or sack_freq are 0 when setting this option, then the
   * current values will remain unchanged.
   *
   * struct sctp_sack_info {
   *     sctp_assoc_t            sack_assoc_id;
   *     uint32_t                sack_delay;
   *     uint32_t                sack_freq;
   * };
   *
   * sack_assoc_id -  This parameter, indicates which association the user
   *    is performing an action upon.  Note that if this field's value is
   *    zero then the endpoints default value is changed (effecting future
   *    associations only).
   *
   * sack_delay -  This parameter contains the number of milliseconds that
   *    the user is requesting the delayed ACK timer be set to.  Note that
   *    this value is defined in the standard to be between 200 and 500
   *    milliseconds.
   *
   * sack_freq -  This parameter contains the number of packets that must
   *    be received before a sack is sent without waiting for the delay
   *    timer to expire.  The default value for this is 2, setting this
   *    value to 1 will disable the delayed sack algorithm.
   */
  
  static int sctp_setsockopt_delayed_ack(struct sock *sk,
  				       char __user *optval, unsigned int optlen)
  {
  	struct sctp_sack_info    params;
  	struct sctp_transport   *trans = NULL;
  	struct sctp_association *asoc = NULL;
  	struct sctp_sock        *sp = sctp_sk(sk);
  
  	if (optlen == sizeof(struct sctp_sack_info)) {
  		if (copy_from_user(&params, optval, optlen))
  			return -EFAULT;
  
  		if (params.sack_delay == 0 && params.sack_freq == 0)
  			return 0;
  	} else if (optlen == sizeof(struct sctp_assoc_value)) {
  		printk(KERN_WARNING "SCTP: Use of struct sctp_assoc_value "
  		       "in delayed_ack socket option deprecated\n");
  		printk(KERN_WARNING "SCTP: Use struct sctp_sack_info instead\n");
  		if (copy_from_user(&params, optval, optlen))
  			return -EFAULT;
  
  		if (params.sack_delay == 0)
  			params.sack_freq = 1;
  		else
  			params.sack_freq = 0;
  	} else
  		return - EINVAL;
  
  	/* Validate value parameter. */
  	if (params.sack_delay > 500)
  		return -EINVAL;
  
  	/* Get association, if sack_assoc_id != 0 and the socket is a one
  	 * to many style socket, and an association was not found, then
  	 * the id was invalid.
  	 */
  	asoc = sctp_id2assoc(sk, params.sack_assoc_id);
  	if (!asoc && params.sack_assoc_id && sctp_style(sk, UDP))
  		return -EINVAL;
  
  	if (params.sack_delay) {
  		if (asoc) {
  			asoc->sackdelay =
  				msecs_to_jiffies(params.sack_delay);
  			asoc->param_flags =
  				(asoc->param_flags & ~SPP_SACKDELAY) |
  				SPP_SACKDELAY_ENABLE;
  		} else {
  			sp->sackdelay = params.sack_delay;
  			sp->param_flags =
  				(sp->param_flags & ~SPP_SACKDELAY) |
  				SPP_SACKDELAY_ENABLE;
  		}
  	}
  
  	if (params.sack_freq == 1) {
  		if (asoc) {
  			asoc->param_flags =
  				(asoc->param_flags & ~SPP_SACKDELAY) |
  				SPP_SACKDELAY_DISABLE;
  		} else {
  			sp->param_flags =
  				(sp->param_flags & ~SPP_SACKDELAY) |
  				SPP_SACKDELAY_DISABLE;
  		}
  	} else if (params.sack_freq > 1) {
  		if (asoc) {
  			asoc->sackfreq = params.sack_freq;
  			asoc->param_flags =
  				(asoc->param_flags & ~SPP_SACKDELAY) |
  				SPP_SACKDELAY_ENABLE;
  		} else {
  			sp->sackfreq = params.sack_freq;
  			sp->param_flags =
  				(sp->param_flags & ~SPP_SACKDELAY) |
  				SPP_SACKDELAY_ENABLE;
  		}
  	}
  
  	/* If change is for association, also apply to each transport. */
  	if (asoc) {
  		list_for_each_entry(trans, &asoc->peer.transport_addr_list,
  				transports) {
  			if (params.sack_delay) {
  				trans->sackdelay =
  					msecs_to_jiffies(params.sack_delay);
  				trans->param_flags =
  					(trans->param_flags & ~SPP_SACKDELAY) |
  					SPP_SACKDELAY_ENABLE;
  			}
  			if (params.sack_freq == 1) {
  				trans->param_flags =
  					(trans->param_flags & ~SPP_SACKDELAY) |
  					SPP_SACKDELAY_DISABLE;
  			} else if (params.sack_freq > 1) {
  				trans->sackfreq = params.sack_freq;
  				trans->param_flags =
  					(trans->param_flags & ~SPP_SACKDELAY) |
  					SPP_SACKDELAY_ENABLE;
  			}
  		}
  	}
  
  	return 0;
  }
  
  /* 7.1.3 Initialization Parameters (SCTP_INITMSG)
   *
   * Applications can specify protocol parameters for the default association
   * initialization.  The option name argument to setsockopt() and getsockopt()
   * is SCTP_INITMSG.
   *
   * Setting initialization parameters is effective only on an unconnected
   * socket (for UDP-style sockets only future associations are effected
   * by the change).  With TCP-style sockets, this option is inherited by
   * sockets derived from a listener socket.
   */
  static int sctp_setsockopt_initmsg(struct sock *sk, char __user *optval, unsigned int optlen)
  {
  	struct sctp_initmsg sinit;
  	struct sctp_sock *sp = sctp_sk(sk);
  
  	if (optlen != sizeof(struct sctp_initmsg))
  		return -EINVAL;
  	if (copy_from_user(&sinit, optval, optlen))
  		return -EFAULT;
  
  	if (sinit.sinit_num_ostreams)
  		sp->initmsg.sinit_num_ostreams = sinit.sinit_num_ostreams;
  	if (sinit.sinit_max_instreams)
  		sp->initmsg.sinit_max_instreams = sinit.sinit_max_instreams;
  	if (sinit.sinit_max_attempts)
  		sp->initmsg.sinit_max_attempts = sinit.sinit_max_attempts;
  	if (sinit.sinit_max_init_timeo)
  		sp->initmsg.sinit_max_init_timeo = sinit.sinit_max_init_timeo;
  
  	return 0;
  }
  
  /*
   * 7.1.14 Set default send parameters (SCTP_DEFAULT_SEND_PARAM)
   *
   *   Applications that wish to use the sendto() system call may wish to
   *   specify a default set of parameters that would normally be supplied
   *   through the inclusion of ancillary data.  This socket option allows
   *   such an application to set the default sctp_sndrcvinfo structure.
   *   The application that wishes to use this socket option simply passes
   *   in to this call the sctp_sndrcvinfo structure defined in Section
   *   5.2.2) The input parameters accepted by this call include
   *   sinfo_stream, sinfo_flags, sinfo_ppid, sinfo_context,
   *   sinfo_timetolive.  The user must provide the sinfo_assoc_id field in
   *   to this call if the caller is using the UDP model.
   */
  static int sctp_setsockopt_default_send_param(struct sock *sk,
  					      char __user *optval,
  					      unsigned int optlen)
  {
  	struct sctp_sndrcvinfo info;
  	struct sctp_association *asoc;
  	struct sctp_sock *sp = sctp_sk(sk);
  
  	if (optlen != sizeof(struct sctp_sndrcvinfo))
  		return -EINVAL;
  	if (copy_from_user(&info, optval, optlen))
  		return -EFAULT;
  
  	asoc = sctp_id2assoc(sk, info.sinfo_assoc_id);
  	if (!asoc && info.sinfo_assoc_id && sctp_style(sk, UDP))
  		return -EINVAL;
  
  	if (asoc) {
  		asoc->default_stream = info.sinfo_stream;
  		asoc->default_flags = info.sinfo_flags;
  		asoc->default_ppid = info.sinfo_ppid;
  		asoc->default_context = info.sinfo_context;
  		asoc->default_timetolive = info.sinfo_timetolive;
  	} else {
  		sp->default_stream = info.sinfo_stream;
  		sp->default_flags = info.sinfo_flags;
  		sp->default_ppid = info.sinfo_ppid;
  		sp->default_context = info.sinfo_context;
  		sp->default_timetolive = info.sinfo_timetolive;
  	}
  
  	return 0;
  }
  
  /* 7.1.10 Set Primary Address (SCTP_PRIMARY_ADDR)
   *
   * Requests that the local SCTP stack use the enclosed peer address as
   * the association primary.  The enclosed address must be one of the
   * association peer's addresses.
   */
  static int sctp_setsockopt_primary_addr(struct sock *sk, char __user *optval,
  					unsigned int optlen)
  {
  	struct sctp_prim prim;
  	struct sctp_transport *trans;
  
  	if (optlen != sizeof(struct sctp_prim))
  		return -EINVAL;
  
  	if (copy_from_user(&prim, optval, sizeof(struct sctp_prim)))
  		return -EFAULT;
  
  	trans = sctp_addr_id2transport(sk, &prim.ssp_addr, prim.ssp_assoc_id);
  	if (!trans)
  		return -EINVAL;
  
  	sctp_assoc_set_primary(trans->asoc, trans);
  
  	return 0;
  }
  
  /*
   * 7.1.5 SCTP_NODELAY
   *
   * Turn on/off any Nagle-like algorithm.  This means that packets are
   * generally sent as soon as possible and no unnecessary delays are
   * introduced, at the cost of more packets in the network.  Expects an
   *  integer boolean flag.
   */
  static int sctp_setsockopt_nodelay(struct sock *sk, char __user *optval,
  				   unsigned int optlen)
  {
  	int val;
  
  	if (optlen < sizeof(int))
  		return -EINVAL;
  	if (get_user(val, (int __user *)optval))
  		return -EFAULT;
  
  	sctp_sk(sk)->nodelay = (val == 0) ? 0 : 1;
  	return 0;
  }
  
  /*
   *
   * 7.1.1 SCTP_RTOINFO
   *
   * The protocol parameters used to initialize and bound retransmission
   * timeout (RTO) are tunable. sctp_rtoinfo structure is used to access
   * and modify these parameters.
   * All parameters are time values, in milliseconds.  A value of 0, when
   * modifying the parameters, indicates that the current value should not
   * be changed.
   *
   */
  static int sctp_setsockopt_rtoinfo(struct sock *sk, char __user *optval, unsigned int optlen)
  {
  	struct sctp_rtoinfo rtoinfo;
  	struct sctp_association *asoc;
  
  	if (optlen != sizeof (struct sctp_rtoinfo))
  		return -EINVAL;
  
  	if (copy_from_user(&rtoinfo, optval, optlen))
  		return -EFAULT;
  
  	asoc = sctp_id2assoc(sk, rtoinfo.srto_assoc_id);
  
  	/* Set the values to the specific association */
  	if (!asoc && rtoinfo.srto_assoc_id && sctp_style(sk, UDP))
  		return -EINVAL;
  
  	if (asoc) {
  		if (rtoinfo.srto_initial != 0)
  			asoc->rto_initial =
  				msecs_to_jiffies(rtoinfo.srto_initial);
  		if (rtoinfo.srto_max != 0)
  			asoc->rto_max = msecs_to_jiffies(rtoinfo.srto_max);
  		if (rtoinfo.srto_min != 0)
  			asoc->rto_min = msecs_to_jiffies(rtoinfo.srto_min);
  	} else {
  		/* If there is no association or the association-id = 0
  		 * set the values to the endpoint.
  		 */
  		struct sctp_sock *sp = sctp_sk(sk);
  
  		if (rtoinfo.srto_initial != 0)
  			sp->rtoinfo.srto_initial = rtoinfo.srto_initial;
  		if (rtoinfo.srto_max != 0)
  			sp->rtoinfo.srto_max = rtoinfo.srto_max;
  		if (rtoinfo.srto_min != 0)
  			sp->rtoinfo.srto_min = rtoinfo.srto_min;
  	}
  
  	return 0;
  }
  
  /*
   *
   * 7.1.2 SCTP_ASSOCINFO
   *
   * This option is used to tune the maximum retransmission attempts
   * of the association.
   * Returns an error if the new association retransmission value is
   * greater than the sum of the retransmission value  of the peer.
   * See [SCTP] for more information.
   *
   */
  static int sctp_setsockopt_associnfo(struct sock *sk, char __user *optval, unsigned int optlen)
  {
  
  	struct sctp_assocparams assocparams;
  	struct sctp_association *asoc;
  
  	if (optlen != sizeof(struct sctp_assocparams))
  		return -EINVAL;
  	if (copy_from_user(&assocparams, optval, optlen))
  		return -EFAULT;
  
  	asoc = sctp_id2assoc(sk, assocparams.sasoc_assoc_id);
  
  	if (!asoc && assocparams.sasoc_assoc_id && sctp_style(sk, UDP))
  		return -EINVAL;
  
  	/* Set the values to the specific association */
  	if (asoc) {
  		if (assocparams.sasoc_asocmaxrxt != 0) {
  			__u32 path_sum = 0;
  			int   paths = 0;
  			struct sctp_transport *peer_addr;
  
  			list_for_each_entry(peer_addr, &asoc->peer.transport_addr_list,
  					transports) {
  				path_sum += peer_addr->pathmaxrxt;
  				paths++;
  			}
  
  			/* Only validate asocmaxrxt if we have more than
  			 * one path/transport.  We do this because path
  			 * retransmissions are only counted when we have more
  			 * then one path.
  			 */
  			if (paths > 1 &&
  			    assocparams.sasoc_asocmaxrxt > path_sum)
  				return -EINVAL;
  
  			asoc->max_retrans = assocparams.sasoc_asocmaxrxt;
  		}
  
  		if (assocparams.sasoc_cookie_life != 0) {
  			asoc->cookie_life.tv_sec =
  					assocparams.sasoc_cookie_life / 1000;
  			asoc->cookie_life.tv_usec =
  					(assocparams.sasoc_cookie_life % 1000)
  					* 1000;
  		}
  	} else {
  		/* Set the values to the endpoint */
  		struct sctp_sock *sp = sctp_sk(sk);
  
  		if (assocparams.sasoc_asocmaxrxt != 0)
  			sp->assocparams.sasoc_asocmaxrxt =
  						assocparams.sasoc_asocmaxrxt;
  		if (assocparams.sasoc_cookie_life != 0)
  			sp->assocparams.sasoc_cookie_life =
  						assocparams.sasoc_cookie_life;
  	}
  	return 0;
  }
  
  /*
   * 7.1.16 Set/clear IPv4 mapped addresses (SCTP_I_WANT_MAPPED_V4_ADDR)
   *
   * This socket option is a boolean flag which turns on or off mapped V4
   * addresses.  If this option is turned on and the socket is type
   * PF_INET6, then IPv4 addresses will be mapped to V6 representation.
   * If this option is turned off, then no mapping will be done of V4
   * addresses and a user will receive both PF_INET6 and PF_INET type
   * addresses on the socket.
   */
  static int sctp_setsockopt_mappedv4(struct sock *sk, char __user *optval, unsigned int optlen)
  {
  	int val;
  	struct sctp_sock *sp = sctp_sk(sk);
  
  	if (optlen < sizeof(int))
  		return -EINVAL;
  	if (get_user(val, (int __user *)optval))
  		return -EFAULT;
  	if (val)
  		sp->v4mapped = 1;
  	else
  		sp->v4mapped = 0;
  
  	return 0;
  }
  
  /*
   * 8.1.16.  Get or Set the Maximum Fragmentation Size (SCTP_MAXSEG)
   * This option will get or set the maximum size to put in any outgoing
   * SCTP DATA chunk.  If a message is larger than this size it will be
   * fragmented by SCTP into the specified size.  Note that the underlying
   * SCTP implementation may fragment into smaller sized chunks when the
   * PMTU of the underlying association is smaller than the value set by
   * the user.  The default value for this option is '0' which indicates
   * the user is NOT limiting fragmentation and only the PMTU will effect
   * SCTP's choice of DATA chunk size.  Note also that values set larger
   * than the maximum size of an IP datagram will effectively let SCTP
   * control fragmentation (i.e. the same as setting this option to 0).
   *
   * The following structure is used to access and modify this parameter:
   *
   * struct sctp_assoc_value {
   *   sctp_assoc_t assoc_id;
   *   uint32_t assoc_value;
   * };
   *
   * assoc_id:  This parameter is ignored for one-to-one style sockets.
   *    For one-to-many style sockets this parameter indicates which
   *    association the user is performing an action upon.  Note that if
   *    this field's value is zero then the endpoints default value is
   *    changed (effecting future associations only).
   * assoc_value:  This parameter specifies the maximum size in bytes.
   */
  static int sctp_setsockopt_maxseg(struct sock *sk, char __user *optval, unsigned int optlen)
  {
  	struct sctp_assoc_value params;
  	struct sctp_association *asoc;
  	struct sctp_sock *sp = sctp_sk(sk);
  	int val;
  
  	if (optlen == sizeof(int)) {
  		printk(KERN_WARNING
  		   "SCTP: Use of int in maxseg socket option deprecated\n");
  		printk(KERN_WARNING
  		   "SCTP: Use struct sctp_assoc_value instead\n");
  		if (copy_from_user(&val, optval, optlen))
  			return -EFAULT;
  		params.assoc_id = 0;
  	} else if (optlen == sizeof(struct sctp_assoc_value)) {
  		if (copy_from_user(&params, optval, optlen))
  			return -EFAULT;
  		val = params.assoc_value;
  	} else
  		return -EINVAL;
  
  	if ((val != 0) && ((val < 8) || (val > SCTP_MAX_CHUNK_LEN)))
  		return -EINVAL;
  
  	asoc = sctp_id2assoc(sk, params.assoc_id);
  	if (!asoc && params.assoc_id && sctp_style(sk, UDP))
  		return -EINVAL;
  
  	if (asoc) {
  		if (val == 0) {
  			val = asoc->pathmtu;
  			val -= sp->pf->af->net_header_len;
  			val -= sizeof(struct sctphdr) +
  					sizeof(struct sctp_data_chunk);
  		}
  		asoc->user_frag = val;
  		asoc->frag_point = sctp_frag_point(asoc, asoc->pathmtu);
  	} else {
  		sp->user_frag = val;
  	}
  
  	return 0;
  }
  
  
  /*
   *  7.1.9 Set Peer Primary Address (SCTP_SET_PEER_PRIMARY_ADDR)
   *
   *   Requests that the peer mark the enclosed address as the association
   *   primary. The enclosed address must be one of the association's
   *   locally bound addresses. The following structure is used to make a
   *   set primary request:
   */
  static int sctp_setsockopt_peer_primary_addr(struct sock *sk, char __user *optval,
  					     unsigned int optlen)
  {
  	struct sctp_sock	*sp;
  	struct sctp_endpoint	*ep;
  	struct sctp_association	*asoc = NULL;
  	struct sctp_setpeerprim	prim;
  	struct sctp_chunk	*chunk;
  	int 			err;
  
  	sp = sctp_sk(sk);
  	ep = sp->ep;
  
  	if (!sctp_addip_enable)
  		return -EPERM;
  
  	if (optlen != sizeof(struct sctp_setpeerprim))
  		return -EINVAL;
  
  	if (copy_from_user(&prim, optval, optlen))
  		return -EFAULT;
  
  	asoc = sctp_id2assoc(sk, prim.sspp_assoc_id);
  	if (!asoc)
  		return -EINVAL;
  
  	if (!asoc->peer.asconf_capable)
  		return -EPERM;
  
  	if (asoc->peer.addip_disabled_mask & SCTP_PARAM_SET_PRIMARY)
  		return -EPERM;
  
  	if (!sctp_state(asoc, ESTABLISHED))
  		return -ENOTCONN;
  
  	if (!sctp_assoc_lookup_laddr(asoc, (union sctp_addr *)&prim.sspp_addr))
  		return -EADDRNOTAVAIL;
  
  	/* Create an ASCONF chunk with SET_PRIMARY parameter	*/
  	chunk = sctp_make_asconf_set_prim(asoc,
  					  (union sctp_addr *)&prim.sspp_addr);
  	if (!chunk)
  		return -ENOMEM;
  
  	err = sctp_send_asconf(asoc, chunk);
  
  	SCTP_DEBUG_PRINTK("We set peer primary addr primitively.\n");
  
  	return err;
  }
  
  static int sctp_setsockopt_adaptation_layer(struct sock *sk, char __user *optval,
  					    unsigned int optlen)
  {
  	struct sctp_setadaptation adaptation;
  
  	if (optlen != sizeof(struct sctp_setadaptation))
  		return -EINVAL;
  	if (copy_from_user(&adaptation, optval, optlen))
  		return -EFAULT;
  
  	sctp_sk(sk)->adaptation_ind = adaptation.ssb_adaptation_ind;
  
  	return 0;
  }
  
  /*
   * 7.1.29.  Set or Get the default context (SCTP_CONTEXT)
   *
   * The context field in the sctp_sndrcvinfo structure is normally only
   * used when a failed message is retrieved holding the value that was
   * sent down on the actual send call.  This option allows the setting of
   * a default context on an association basis that will be received on
   * reading messages from the peer.  This is especially helpful in the
   * one-2-many model for an application to keep some reference to an
   * internal state machine that is processing messages on the
   * association.  Note that the setting of this value only effects
   * received messages from the peer and does not effect the value that is
   * saved with outbound messages.
   */
  static int sctp_setsockopt_context(struct sock *sk, char __user *optval,
  				   unsigned int optlen)
  {
  	struct sctp_assoc_value params;
  	struct sctp_sock *sp;
  	struct sctp_association *asoc;
  
  	if (optlen != sizeof(struct sctp_assoc_value))
  		return -EINVAL;
  	if (copy_from_user(&params, optval, optlen))
  		return -EFAULT;
  
  	sp = sctp_sk(sk);
  
  	if (params.assoc_id != 0) {
  		asoc = sctp_id2assoc(sk, params.assoc_id);
  		if (!asoc)
  			return -EINVAL;
  		asoc->default_rcv_context = params.assoc_value;
  	} else {
  		sp->default_rcv_context = params.assoc_value;
  	}
  
  	return 0;
  }
  
  /*
   * 7.1.24.  Get or set fragmented interleave (SCTP_FRAGMENT_INTERLEAVE)
   *
   * This options will at a minimum specify if the implementation is doing
   * fragmented interleave.  Fragmented interleave, for a one to many
   * socket, is when subsequent calls to receive a message may return
   * parts of messages from different associations.  Some implementations
   * may allow you to turn this value on or off.  If so, when turned off,
   * no fragment interleave will occur (which will cause a head of line
   * blocking amongst multiple associations sharing the same one to many
   * socket).  When this option is turned on, then each receive call may
   * come from a different association (thus the user must receive data
   * with the extended calls (e.g. sctp_recvmsg) to keep track of which
   * association each receive belongs to.
   *
   * This option takes a boolean value.  A non-zero value indicates that
   * fragmented interleave is on.  A value of zero indicates that
   * fragmented interleave is off.
   *
   * Note that it is important that an implementation that allows this
   * option to be turned on, have it off by default.  Otherwise an unaware
   * application using the one to many model may become confused and act
   * incorrectly.
   */
  static int sctp_setsockopt_fragment_interleave(struct sock *sk,
  					       char __user *optval,
  					       unsigned int optlen)
  {
  	int val;
  
  	if (optlen != sizeof(int))
  		return -EINVAL;
  	if (get_user(val, (int __user *)optval))
  		return -EFAULT;
  
  	sctp_sk(sk)->frag_interleave = (val == 0) ? 0 : 1;
  
  	return 0;
  }
  
  /*
   * 8.1.21.  Set or Get the SCTP Partial Delivery Point
   *       (SCTP_PARTIAL_DELIVERY_POINT)
   *
   * This option will set or get the SCTP partial delivery point.  This
   * point is the size of a message where the partial delivery API will be
   * invoked to help free up rwnd space for the peer.  Setting this to a
   * lower value will cause partial deliveries to happen more often.  The
   * calls argument is an integer that sets or gets the partial delivery
   * point.  Note also that the call will fail if the user attempts to set
   * this value larger than the socket receive buffer size.
   *
   * Note that any single message having a length smaller than or equal to
   * the SCTP partial delivery point will be delivered in one single read
   * call as long as the user provided buffer is large enough to hold the
   * message.
   */
  static int sctp_setsockopt_partial_delivery_point(struct sock *sk,
  						  char __user *optval,
  						  unsigned int optlen)
  {
  	u32 val;
  
  	if (optlen != sizeof(u32))
  		return -EINVAL;
  	if (get_user(val, (int __user *)optval))
  		return -EFAULT;
  
  	/* Note: We double the receive buffer from what the user sets
  	 * it to be, also initial rwnd is based on rcvbuf/2.
  	 */
  	if (val > (sk->sk_rcvbuf >> 1))
  		return -EINVAL;
  
  	sctp_sk(sk)->pd_point = val;
  
  	return 0; /* is this the right error code? */
  }
  
  /*
   * 7.1.28.  Set or Get the maximum burst (SCTP_MAX_BURST)
   *
   * This option will allow a user to change the maximum burst of packets
   * that can be emitted by this association.  Note that the default value
   * is 4, and some implementations may restrict this setting so that it
   * can only be lowered.
   *
   * NOTE: This text doesn't seem right.  Do this on a socket basis with
   * future associations inheriting the socket value.
   */
  static int sctp_setsockopt_maxburst(struct sock *sk,
  				    char __user *optval,
  				    unsigned int optlen)
  {
  	struct sctp_assoc_value params;
  	struct sctp_sock *sp;
  	struct sctp_association *asoc;
  	int val;
  	int assoc_id = 0;
  
  	if (optlen == sizeof(int)) {
  		printk(KERN_WARNING
  		   "SCTP: Use of int in max_burst socket option deprecated\n");
  		printk(KERN_WARNING
  		   "SCTP: Use struct sctp_assoc_value instead\n");
  		if (copy_from_user(&val, optval, optlen))
  			return -EFAULT;
  	} else if (optlen == sizeof(struct sctp_assoc_value)) {
  		if (copy_from_user(&params, optval, optlen))
  			return -EFAULT;
  		val = params.assoc_value;
  		assoc_id = params.assoc_id;
  	} else
  		return -EINVAL;
  
  	sp = sctp_sk(sk);
  
  	if (assoc_id != 0) {
  		asoc = sctp_id2assoc(sk, assoc_id);
  		if (!asoc)
  			return -EINVAL;
  		asoc->max_burst = val;
  	} else
  		sp->max_burst = val;
  
  	return 0;
  }
  
  /*
   * 7.1.18.  Add a chunk that must be authenticated (SCTP_AUTH_CHUNK)
   *
   * This set option adds a chunk type that the user is requesting to be
   * received only in an authenticated way.  Changes to the list of chunks
   * will only effect future associations on the socket.
   */
  static int sctp_setsockopt_auth_chunk(struct sock *sk,
  				      char __user *optval,
  				      unsigned int optlen)
  {
  	struct sctp_authchunk val;
  
  	if (!sctp_auth_enable)
  		return -EACCES;
  
  	if (optlen != sizeof(struct sctp_authchunk))
  		return -EINVAL;
  	if (copy_from_user(&val, optval, optlen))
  		return -EFAULT;
  
  	switch (val.sauth_chunk) {
  		case SCTP_CID_INIT:
  		case SCTP_CID_INIT_ACK:
  		case SCTP_CID_SHUTDOWN_COMPLETE:
  		case SCTP_CID_AUTH:
  			return -EINVAL;
  	}
  
  	/* add this chunk id to the endpoint */
  	return sctp_auth_ep_add_chunkid(sctp_sk(sk)->ep, val.sauth_chunk);
  }
  
  /*
   * 7.1.19.  Get or set the list of supported HMAC Identifiers (SCTP_HMAC_IDENT)
   *
   * This option gets or sets the list of HMAC algorithms that the local
   * endpoint requires the peer to use.
   */
  static int sctp_setsockopt_hmac_ident(struct sock *sk,
  				      char __user *optval,
  				      unsigned int optlen)
  {
  	struct sctp_hmacalgo *hmacs;
  	u32 idents;
  	int err;
  
  	if (!sctp_auth_enable)
  		return -EACCES;
  
  	if (optlen < sizeof(struct sctp_hmacalgo))
  		return -EINVAL;
  
  	hmacs = kmalloc(optlen, GFP_KERNEL);
  	if (!hmacs)
  		return -ENOMEM;
  
  	if (copy_from_user(hmacs, optval, optlen)) {
  		err = -EFAULT;
  		goto out;
  	}
  
  	idents = hmacs->shmac_num_idents;
  	if (idents == 0 || idents > SCTP_AUTH_NUM_HMACS ||
  	    (idents * sizeof(u16)) > (optlen - sizeof(struct sctp_hmacalgo))) {
  		err = -EINVAL;
  		goto out;
  	}
  
  	err = sctp_auth_ep_set_hmacs(sctp_sk(sk)->ep, hmacs);
  out:
  	kfree(hmacs);
  	return err;
  }
  
  /*
   * 7.1.20.  Set a shared key (SCTP_AUTH_KEY)
   *
   * This option will set a shared secret key which is used to build an
   * association shared key.
   */
  static int sctp_setsockopt_auth_key(struct sock *sk,
  				    char __user *optval,
  				    unsigned int optlen)
  {
  	struct sctp_authkey *authkey;
  	struct sctp_association *asoc;
  	int ret;
  
  	if (!sctp_auth_enable)
  		return -EACCES;
  
  	if (optlen <= sizeof(struct sctp_authkey))
  		return -EINVAL;
  
  	authkey = kmalloc(optlen, GFP_KERNEL);
  	if (!authkey)
  		return -ENOMEM;
  
  	if (copy_from_user(authkey, optval, optlen)) {
  		ret = -EFAULT;
  		goto out;
  	}
  
  	if (authkey->sca_keylength > optlen - sizeof(struct sctp_authkey)) {
  		ret = -EINVAL;
  		goto out;
  	}
  
  	asoc = sctp_id2assoc(sk, authkey->sca_assoc_id);
  	if (!asoc && authkey->sca_assoc_id && sctp_style(sk, UDP)) {
  		ret = -EINVAL;
  		goto out;
  	}
  
  	ret = sctp_auth_set_key(sctp_sk(sk)->ep, asoc, authkey);
  out:
  	kfree(authkey);
  	return ret;
  }
  
  /*
   * 7.1.21.  Get or set the active shared key (SCTP_AUTH_ACTIVE_KEY)
   *
   * This option will get or set the active shared key to be used to build
   * the association shared key.
   */
  static int sctp_setsockopt_active_key(struct sock *sk,
  				      char __user *optval,
  				      unsigned int optlen)
  {
  	struct sctp_authkeyid val;
  	struct sctp_association *asoc;
  
  	if (!sctp_auth_enable)
  		return -EACCES;
  
  	if (optlen != sizeof(struct sctp_authkeyid))
  		return -EINVAL;
  	if (copy_from_user(&val, optval, optlen))
  		return -EFAULT;
  
  	asoc = sctp_id2assoc(sk, val.scact_assoc_id);
  	if (!asoc && val.scact_assoc_id && sctp_style(sk, UDP))
  		return -EINVAL;
  
  	return sctp_auth_set_active_key(sctp_sk(sk)->ep, asoc,
  					val.scact_keynumber);
  }
  
  /*
   * 7.1.22.  Delete a shared key (SCTP_AUTH_DELETE_KEY)
   *
   * This set option will delete a shared secret key from use.
   */
  static int sctp_setsockopt_del_key(struct sock *sk,
  				   char __user *optval,
  				   unsigned int optlen)
  {
  	struct sctp_authkeyid val;
  	struct sctp_association *asoc;
  
  	if (!sctp_auth_enable)
  		return -EACCES;
  
  	if (optlen != sizeof(struct sctp_authkeyid))
  		return -EINVAL;
  	if (copy_from_user(&val, optval, optlen))
  		return -EFAULT;
  
  	asoc = sctp_id2assoc(sk, val.scact_assoc_id);
  	if (!asoc && val.scact_assoc_id && sctp_style(sk, UDP))
  		return -EINVAL;
  
  	return sctp_auth_del_key_id(sctp_sk(sk)->ep, asoc,
  				    val.scact_keynumber);
  
  }
  
  
  /* API 6.2 setsockopt(), getsockopt()
   *
   * Applications use setsockopt() and getsockopt() to set or retrieve
   * socket options.  Socket options are used to change the default
   * behavior of sockets calls.  They are described in Section 7.
   *
   * The syntax is:
   *
   *   ret = getsockopt(int sd, int level, int optname, void __user *optval,
   *                    int __user *optlen);
   *   ret = setsockopt(int sd, int level, int optname, const void __user *optval,
   *                    int optlen);
   *
   *   sd      - the socket descript.
   *   level   - set to IPPROTO_SCTP for all SCTP options.
   *   optname - the option name.
   *   optval  - the buffer to store the value of the option.
   *   optlen  - the size of the buffer.
   */
  SCTP_STATIC int sctp_setsockopt(struct sock *sk, int level, int optname,
  				char __user *optval, unsigned int optlen)
  {
  	int retval = 0;
  
  	SCTP_DEBUG_PRINTK("sctp_setsockopt(sk: %p... optname: %d)\n",
  			  sk, optname);
  
  	/* I can hardly begin to describe how wrong this is.  This is
  	 * so broken as to be worse than useless.  The API draft
  	 * REALLY is NOT helpful here...  I am not convinced that the
  	 * semantics of setsockopt() with a level OTHER THAN SOL_SCTP
  	 * are at all well-founded.
  	 */
  	if (level != SOL_SCTP) {
  		struct sctp_af *af = sctp_sk(sk)->pf->af;
  		retval = af->setsockopt(sk, level, optname, optval, optlen);
  		goto out_nounlock;
  	}
  
  	sctp_lock_sock(sk);
  
  	switch (optname) {
  	case SCTP_SOCKOPT_BINDX_ADD:
  		/* 'optlen' is the size of the addresses buffer. */
  		retval = sctp_setsockopt_bindx(sk, (struct sockaddr __user *)optval,
  					       optlen, SCTP_BINDX_ADD_ADDR);
  		break;
  
  	case SCTP_SOCKOPT_BINDX_REM:
  		/* 'optlen' is the size of the addresses buffer. */
  		retval = sctp_setsockopt_bindx(sk, (struct sockaddr __user *)optval,
  					       optlen, SCTP_BINDX_REM_ADDR);
  		break;
  
  	case SCTP_SOCKOPT_CONNECTX_OLD:
  		/* 'optlen' is the size of the addresses buffer. */
  		retval = sctp_setsockopt_connectx_old(sk,
  					    (struct sockaddr __user *)optval,
  					    optlen);
  		break;
  
  	case SCTP_SOCKOPT_CONNECTX:
  		/* 'optlen' is the size of the addresses buffer. */
  		retval = sctp_setsockopt_connectx(sk,
  					    (struct sockaddr __user *)optval,
  					    optlen);
  		break;
  
  	case SCTP_DISABLE_FRAGMENTS:
  		retval = sctp_setsockopt_disable_fragments(sk, optval, optlen);
  		break;
  
  	case SCTP_EVENTS:
  		retval = sctp_setsockopt_events(sk, optval, optlen);
  		break;
  
  	case SCTP_AUTOCLOSE:
  		retval = sctp_setsockopt_autoclose(sk, optval, optlen);
  		break;
  
  	case SCTP_PEER_ADDR_PARAMS:
  		retval = sctp_setsockopt_peer_addr_params(sk, optval, optlen);
  		break;
  
  	case SCTP_DELAYED_ACK:
  		retval = sctp_setsockopt_delayed_ack(sk, optval, optlen);
  		break;
  	case SCTP_PARTIAL_DELIVERY_POINT:
  		retval = sctp_setsockopt_partial_delivery_point(sk, optval, optlen);
  		break;
  
  	case SCTP_INITMSG:
  		retval = sctp_setsockopt_initmsg(sk, optval, optlen);
  		break;
  	case SCTP_DEFAULT_SEND_PARAM:
  		retval = sctp_setsockopt_default_send_param(sk, optval,
  							    optlen);
  		break;
  	case SCTP_PRIMARY_ADDR:
  		retval = sctp_setsockopt_primary_addr(sk, optval, optlen);
  		break;
  	case SCTP_SET_PEER_PRIMARY_ADDR:
  		retval = sctp_setsockopt_peer_primary_addr(sk, optval, optlen);
  		break;
  	case SCTP_NODELAY:
  		retval = sctp_setsockopt_nodelay(sk, optval, optlen);
  		break;
  	case SCTP_RTOINFO:
  		retval = sctp_setsockopt_rtoinfo(sk, optval, optlen);
  		break;
  	case SCTP_ASSOCINFO:
  		retval = sctp_setsockopt_associnfo(sk, optval, optlen);
  		break;
  	case SCTP_I_WANT_MAPPED_V4_ADDR:
  		retval = sctp_setsockopt_mappedv4(sk, optval, optlen);
  		break;
  	case SCTP_MAXSEG:
  		retval = sctp_setsockopt_maxseg(sk, optval, optlen);
  		break;
  	case SCTP_ADAPTATION_LAYER:
  		retval = sctp_setsockopt_adaptation_layer(sk, optval, optlen);
  		break;
  	case SCTP_CONTEXT:
  		retval = sctp_setsockopt_context(sk, optval, optlen);
  		break;
  	case SCTP_FRAGMENT_INTERLEAVE:
  		retval = sctp_setsockopt_fragment_interleave(sk, optval, optlen);
  		break;
  	case SCTP_MAX_BURST:
  		retval = sctp_setsockopt_maxburst(sk, optval, optlen);
  		break;
  	case SCTP_AUTH_CHUNK:
  		retval = sctp_setsockopt_auth_chunk(sk, optval, optlen);
  		break;
  	case SCTP_HMAC_IDENT:
  		retval = sctp_setsockopt_hmac_ident(sk, optval, optlen);
  		break;
  	case SCTP_AUTH_KEY:
  		retval = sctp_setsockopt_auth_key(sk, optval, optlen);
  		break;
  	case SCTP_AUTH_ACTIVE_KEY:
  		retval = sctp_setsockopt_active_key(sk, optval, optlen);
  		break;
  	case SCTP_AUTH_DELETE_KEY:
  		retval = sctp_setsockopt_del_key(sk, optval, optlen);
  		break;
  	default:
  		retval = -ENOPROTOOPT;
  		break;
  	}
  
  	sctp_release_sock(sk);
  
  out_nounlock:
  	return retval;
  }
  
  /* API 3.1.6 connect() - UDP Style Syntax
   *
   * An application may use the connect() call in the UDP model to initiate an
   * association without sending data.
   *
   * The syntax is:
   *
   * ret = connect(int sd, const struct sockaddr *nam, socklen_t len);
   *
   * sd: the socket descriptor to have a new association added to.
   *
   * nam: the address structure (either struct sockaddr_in or struct
   *    sockaddr_in6 defined in RFC2553 [7]).
   *
   * len: the size of the address.
   */
  SCTP_STATIC int sctp_connect(struct sock *sk, struct sockaddr *addr,
  			     int addr_len)
  {
  	int err = 0;
  	struct sctp_af *af;
  
  	sctp_lock_sock(sk);
  
  	SCTP_DEBUG_PRINTK("%s - sk: %p, sockaddr: %p, addr_len: %d\n",
  			  __func__, sk, addr, addr_len);
  
  	/* Validate addr_len before calling common connect/connectx routine. */
  	af = sctp_get_af_specific(addr->sa_family);
  	if (!af || addr_len < af->sockaddr_len) {
  		err = -EINVAL;
  	} else {
  		/* Pass correct addr len to common routine (so it knows there
  		 * is only one address being passed.
  		 */
  		err = __sctp_connect(sk, addr, af->sockaddr_len, NULL);
  	}
  
  	sctp_release_sock(sk);
  	return err;
  }
  
  /* FIXME: Write comments. */
  SCTP_STATIC int sctp_disconnect(struct sock *sk, int flags)
  {
  	return -EOPNOTSUPP; /* STUB */
  }
  
  /* 4.1.4 accept() - TCP Style Syntax
   *
   * Applications use accept() call to remove an established SCTP
   * association from the accept queue of the endpoint.  A new socket
   * descriptor will be returned from accept() to represent the newly
   * formed association.
   */
  SCTP_STATIC struct sock *sctp_accept(struct sock *sk, int flags, int *err)
  {
  	struct sctp_sock *sp;
  	struct sctp_endpoint *ep;
  	struct sock *newsk = NULL;
  	struct sctp_association *asoc;
  	long timeo;
  	int error = 0;
  
  	sctp_lock_sock(sk);
  
  	sp = sctp_sk(sk);
  	ep = sp->ep;
  
  	if (!sctp_style(sk, TCP)) {
  		error = -EOPNOTSUPP;
  		goto out;
  	}
  
  	if (!sctp_sstate(sk, LISTENING)) {
  		error = -EINVAL;
  		goto out;
  	}
  
  	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
  
  	error = sctp_wait_for_accept(sk, timeo);
  	if (error)
  		goto out;
  
  	/* We treat the list of associations on the endpoint as the accept
  	 * queue and pick the first association on the list.
  	 */
  	asoc = list_entry(ep->asocs.next, struct sctp_association, asocs);
  
  	newsk = sp->pf->create_accept_sk(sk, asoc);
  	if (!newsk) {
  		error = -ENOMEM;
  		goto out;
  	}
  
  	/* Populate the fields of the newsk from the oldsk and migrate the
  	 * asoc to the newsk.
  	 */
  	sctp_sock_migrate(sk, newsk, asoc, SCTP_SOCKET_TCP);
  
  out:
  	sctp_release_sock(sk);
  	*err = error;
  	return newsk;
  }
  
  /* The SCTP ioctl handler. */
  SCTP_STATIC int sctp_ioctl(struct sock *sk, int cmd, unsigned long arg)
  {
  	return -ENOIOCTLCMD;
  }
  
  /* This is the function which gets called during socket creation to
   * initialized the SCTP-specific portion of the sock.
   * The sock structure should already be zero-filled memory.
   */
  SCTP_STATIC int sctp_init_sock(struct sock *sk)
  {
  	struct sctp_endpoint *ep;
  	struct sctp_sock *sp;
  
  	SCTP_DEBUG_PRINTK("sctp_init_sock(sk: %p)\n", sk);
  
  	sp = sctp_sk(sk);
  
  	/* Initialize the SCTP per socket area.  */
  	switch (sk->sk_type) {
  	case SOCK_SEQPACKET:
  		sp->type = SCTP_SOCKET_UDP;
  		break;
  	case SOCK_STREAM:
  		sp->type = SCTP_SOCKET_TCP;
  		break;
  	default:
  		return -ESOCKTNOSUPPORT;
  	}
  
  	/* Initialize default send parameters. These parameters can be
  	 * modified with the SCTP_DEFAULT_SEND_PARAM socket option.
  	 */
  	sp->default_stream = 0;
  	sp->default_ppid = 0;
  	sp->default_flags = 0;
  	sp->default_context = 0;
  	sp->default_timetolive = 0;
  
  	sp->default_rcv_context = 0;
  	sp->max_burst = sctp_max_burst;
  
  	/* Initialize default setup parameters. These parameters
  	 * can be modified with the SCTP_INITMSG socket option or
  	 * overridden by the SCTP_INIT CMSG.
  	 */
  	sp->initmsg.sinit_num_ostreams   = sctp_max_outstreams;
  	sp->initmsg.sinit_max_instreams  = sctp_max_instreams;
  	sp->initmsg.sinit_max_attempts   = sctp_max_retrans_init;
  	sp->initmsg.sinit_max_init_timeo = sctp_rto_max;
  
  	/* Initialize default RTO related parameters.  These parameters can
  	 * be modified for with the SCTP_RTOINFO socket option.
  	 */
  	sp->rtoinfo.srto_initial = sctp_rto_initial;
  	sp->rtoinfo.srto_max     = sctp_rto_max;
  	sp->rtoinfo.srto_min     = sctp_rto_min;
  
  	/* Initialize default association related parameters. These parameters
  	 * can be modified with the SCTP_ASSOCINFO socket option.
  	 */
  	sp->assocparams.sasoc_asocmaxrxt = sctp_max_retrans_association;
  	sp->assocparams.sasoc_number_peer_destinations = 0;
  	sp->assocparams.sasoc_peer_rwnd = 0;
  	sp->assocparams.sasoc_local_rwnd = 0;
  	sp->assocparams.sasoc_cookie_life = sctp_valid_cookie_life;
  
  	/* Initialize default event subscriptions. By default, all the
  	 * options are off.
  	 */
  	memset(&sp->subscribe, 0, sizeof(struct sctp_event_subscribe));
  
  	/* Default Peer Address Parameters.  These defaults can
  	 * be modified via SCTP_PEER_ADDR_PARAMS
  	 */
  	sp->hbinterval  = sctp_hb_interval;
  	sp->pathmaxrxt  = sctp_max_retrans_path;
  	sp->pathmtu     = 0; // allow default discovery
  	sp->sackdelay   = sctp_sack_timeout;
  	sp->sackfreq	= 2;
  	sp->param_flags = SPP_HB_ENABLE |
  			  SPP_PMTUD_ENABLE |
  			  SPP_SACKDELAY_ENABLE;
  
  	/* If enabled no SCTP message fragmentation will be performed.
  	 * Configure through SCTP_DISABLE_FRAGMENTS socket option.
  	 */
  	sp->disable_fragments = 0;
  
  	/* Enable Nagle algorithm by default.  */
  	sp->nodelay           = 0;
  
  	/* Enable by default. */
  	sp->v4mapped          = 1;
  
  	/* Auto-close idle associations after the configured
  	 * number of seconds.  A value of 0 disables this
  	 * feature.  Configure through the SCTP_AUTOCLOSE socket option,
  	 * for UDP-style sockets only.
  	 */
  	sp->autoclose         = 0;
  
  	/* User specified fragmentation limit. */
  	sp->user_frag         = 0;
  
  	sp->adaptation_ind = 0;
  
  	sp->pf = sctp_get_pf_specific(sk->sk_family);
  
  	/* Control variables for partial data delivery. */
  	atomic_set(&sp->pd_mode, 0);
  	skb_queue_head_init(&sp->pd_lobby);
  	sp->frag_interleave = 0;
  
  	/* Create a per socket endpoint structure.  Even if we
  	 * change the data structure relationships, this may still
  	 * be useful for storing pre-connect address information.
  	 */
  	ep = sctp_endpoint_new(sk, GFP_KERNEL);
  	if (!ep)
  		return -ENOMEM;
  
  	sp->ep = ep;
  	sp->hmac = NULL;
  
  	SCTP_DBG_OBJCNT_INC(sock);
  
  	/* Set socket backlog limit. */
  	sk->sk_backlog.limit = sysctl_sctp_rmem[1];
  
  	local_bh_disable();
  	percpu_counter_inc(&sctp_sockets_allocated);
  	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
  	local_bh_enable();
  
  	return 0;
  }
  
  /* Cleanup any SCTP per socket resources.  */
  SCTP_STATIC void sctp_destroy_sock(struct sock *sk)
  {
  	struct sctp_endpoint *ep;
  
  	SCTP_DEBUG_PRINTK("sctp_destroy_sock(sk: %p)\n", sk);
  
  	/* Release our hold on the endpoint. */
  	ep = sctp_sk(sk)->ep;
  	sctp_endpoint_free(ep);
  	local_bh_disable();
  	percpu_counter_dec(&sctp_sockets_allocated);
  	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
  	local_bh_enable();
  }
  
  /* API 4.1.7 shutdown() - TCP Style Syntax
   *     int shutdown(int socket, int how);
   *
   *     sd      - the socket descriptor of the association to be closed.
   *     how     - Specifies the type of shutdown.  The  values  are
   *               as follows:
   *               SHUT_RD
   *                     Disables further receive operations. No SCTP
   *                     protocol action is taken.
   *               SHUT_WR
   *                     Disables further send operations, and initiates
   *                     the SCTP shutdown sequence.
   *               SHUT_RDWR
   *                     Disables further send  and  receive  operations
   *                     and initiates the SCTP shutdown sequence.
   */
  SCTP_STATIC void sctp_shutdown(struct sock *sk, int how)
  {
  	struct sctp_endpoint *ep;
  	struct sctp_association *asoc;
  
  	if (!sctp_style(sk, TCP))
  		return;
  
  	if (how & SEND_SHUTDOWN) {
  		ep = sctp_sk(sk)->ep;
  		if (!list_empty(&ep->asocs)) {
  			asoc = list_entry(ep->asocs.next,
  					  struct sctp_association, asocs);
  			sctp_primitive_SHUTDOWN(asoc, NULL);
  		}
  	}
  }
  
  /* 7.2.1 Association Status (SCTP_STATUS)
  
   * Applications can retrieve current status information about an
   * association, including association state, peer receiver window size,
   * number of unacked data chunks, and number of data chunks pending
   * receipt.  This information is read-only.
   */
  static int sctp_getsockopt_sctp_status(struct sock *sk, int len,
  				       char __user *optval,
  				       int __user *optlen)
  {
  	struct sctp_status status;
  	struct sctp_association *asoc = NULL;
  	struct sctp_transport *transport;
  	sctp_assoc_t associd;
  	int retval = 0;
  
  	if (len < sizeof(status)) {
  		retval = -EINVAL;
  		goto out;
  	}
  
  	len = sizeof(status);
  	if (copy_from_user(&status, optval, len)) {
  		retval = -EFAULT;
  		goto out;
  	}
  
  	associd = status.sstat_assoc_id;
  	asoc = sctp_id2assoc(sk, associd);
  	if (!asoc) {
  		retval = -EINVAL;
  		goto out;
  	}
  
  	transport = asoc->peer.primary_path;
  
  	status.sstat_assoc_id = sctp_assoc2id(asoc);
  	status.sstat_state = asoc->state;
  	status.sstat_rwnd =  asoc->peer.rwnd;
  	status.sstat_unackdata = asoc->unack_data;
  
  	status.sstat_penddata = sctp_tsnmap_pending(&asoc->peer.tsn_map);
  	status.sstat_instrms = asoc->c.sinit_max_instreams;
  	status.sstat_outstrms = asoc->c.sinit_num_ostreams;
  	status.sstat_fragmentation_point = asoc->frag_point;
  	status.sstat_primary.spinfo_assoc_id = sctp_assoc2id(transport->asoc);
  	memcpy(&status.sstat_primary.spinfo_address, &transport->ipaddr,
  			transport->af_specific->sockaddr_len);
  	/* Map ipv4 address into v4-mapped-on-v6 address.  */
  	sctp_get_pf_specific(sk->sk_family)->addr_v4map(sctp_sk(sk),
  		(union sctp_addr *)&status.sstat_primary.spinfo_address);
  	status.sstat_primary.spinfo_state = transport->state;
  	status.sstat_primary.spinfo_cwnd = transport->cwnd;
  	status.sstat_primary.spinfo_srtt = transport->srtt;
  	status.sstat_primary.spinfo_rto = jiffies_to_msecs(transport->rto);
  	status.sstat_primary.spinfo_mtu = transport->pathmtu;
  
  	if (status.sstat_primary.spinfo_state == SCTP_UNKNOWN)
  		status.sstat_primary.spinfo_state = SCTP_ACTIVE;
  
  	if (put_user(len, optlen)) {
  		retval = -EFAULT;
  		goto out;
  	}
  
  	SCTP_DEBUG_PRINTK("sctp_getsockopt_sctp_status(%d): %d %d %d\n",
  			  len, status.sstat_state, status.sstat_rwnd,
  			  status.sstat_assoc_id);
  
  	if (copy_to_user(optval, &status, len)) {
  		retval = -EFAULT;
  		goto out;
  	}
  
  out:
  	return (retval);
  }
  
  
  /* 7.2.2 Peer Address Information (SCTP_GET_PEER_ADDR_INFO)
   *
   * Applications can retrieve information about a specific peer address
   * of an association, including its reachability state, congestion
   * window, and retransmission timer values.  This information is
   * read-only.
   */
  static int sctp_getsockopt_peer_addr_info(struct sock *sk, int len,
  					  char __user *optval,
  					  int __user *optlen)
  {
  	struct sctp_paddrinfo pinfo;
  	struct sctp_transport *transport;
  	int retval = 0;
  
  	if (len < sizeof(pinfo)) {
  		retval = -EINVAL;
  		goto out;
  	}
  
  	len = sizeof(pinfo);
  	if (copy_from_user(&pinfo, optval, len)) {
  		retval = -EFAULT;
  		goto out;
  	}
  
  	transport = sctp_addr_id2transport(sk, &pinfo.spinfo_address,
  					   pinfo.spinfo_assoc_id);
  	if (!transport)
  		return -EINVAL;
  
  	pinfo.spinfo_assoc_id = sctp_assoc2id(transport->asoc);
  	pinfo.spinfo_state = transport->state;
  	pinfo.spinfo_cwnd = transport->cwnd;
  	pinfo.spinfo_srtt = transport->srtt;
  	pinfo.spinfo_rto = jiffies_to_msecs(transport->rto);
  	pinfo.spinfo_mtu = transport->pathmtu;
  
  	if (pinfo.spinfo_state == SCTP_UNKNOWN)
  		pinfo.spinfo_state = SCTP_ACTIVE;
  
  	if (put_user(len, optlen)) {
  		retval = -EFAULT;
  		goto out;
  	}
  
  	if (copy_to_user(optval, &pinfo, len)) {
  		retval = -EFAULT;
  		goto out;
  	}
  
  out:
  	return (retval);
  }
  
  /* 7.1.12 Enable/Disable message fragmentation (SCTP_DISABLE_FRAGMENTS)
   *
   * This option is a on/off flag.  If enabled no SCTP message
   * fragmentation will be performed.  Instead if a message being sent
   * exceeds the current PMTU size, the message will NOT be sent and
   * instead a error will be indicated to the user.
   */
  static int sctp_getsockopt_disable_fragments(struct sock *sk, int len,
  					char __user *optval, int __user *optlen)
  {
  	int val;
  
  	if (len < sizeof(int))
  		return -EINVAL;
  
  	len = sizeof(int);
  	val = (sctp_sk(sk)->disable_fragments == 1);
  	if (put_user(len, optlen))
  		return -EFAULT;
  	if (copy_to_user(optval, &val, len))
  		return -EFAULT;
  	return 0;
  }
  
  /* 7.1.15 Set notification and ancillary events (SCTP_EVENTS)
   *
   * This socket option is used to specify various notifications and
   * ancillary data the user wishes to receive.
   */
  static int sctp_getsockopt_events(struct sock *sk, int len, char __user *optval,
  				  int __user *optlen)
  {
  	if (len < sizeof(struct sctp_event_subscribe))
  		return -EINVAL;
  	len = sizeof(struct sctp_event_subscribe);
  	if (put_user(len, optlen))
  		return -EFAULT;
  	if (copy_to_user(optval, &sctp_sk(sk)->subscribe, len))
  		return -EFAULT;
  	return 0;
  }
  
  /* 7.1.8 Automatic Close of associations (SCTP_AUTOCLOSE)
   *
   * This socket option is applicable to the UDP-style socket only.  When
   * set it will cause associations that are idle for more than the
   * specified number of seconds to automatically close.  An association
   * being idle is defined an association that has NOT sent or received
   * user data.  The special value of '0' indicates that no automatic
   * close of any associations should be performed.  The option expects an
   * integer defining the number of seconds of idle time before an
   * association is closed.
   */
  static int sctp_getsockopt_autoclose(struct sock *sk, int len, char __user *optval, int __user *optlen)
  {
  	/* Applicable to UDP-style socket only */
  	if (sctp_style(sk, TCP))
  		return -EOPNOTSUPP;
  	if (len < sizeof(int))
  		return -EINVAL;
  	len = sizeof(int);
  	if (put_user(len, optlen))
  		return -EFAULT;
  	if (copy_to_user(optval, &sctp_sk(sk)->autoclose, sizeof(int)))
  		return -EFAULT;
  	return 0;
  }
  
  /* Helper routine to branch off an association to a new socket.  */
  SCTP_STATIC int sctp_do_peeloff(struct sctp_association *asoc,
  				struct socket **sockp)
  {
  	struct sock *sk = asoc->base.sk;
  	struct socket *sock;
  	struct sctp_af *af;
  	int err = 0;
  
  	/* An association cannot be branched off from an already peeled-off
  	 * socket, nor is this supported for tcp style sockets.
  	 */
  	if (!sctp_style(sk, UDP))
  		return -EINVAL;
  
  	/* Create a new socket.  */
  	err = sock_create(sk->sk_family, SOCK_SEQPACKET, IPPROTO_SCTP, &sock);
  	if (err < 0)
  		return err;
  
  	sctp_copy_sock(sock->sk, sk, asoc);
  
  	/* Make peeled-off sockets more like 1-1 accepted sockets.
  	 * Set the daddr and initialize id to something more random
  	 */
  	af = sctp_get_af_specific(asoc->peer.primary_addr.sa.sa_family);
  	af->to_sk_daddr(&asoc->peer.primary_addr, sk);
  
  	/* Populate the fields of the newsk from the oldsk and migrate the
  	 * asoc to the newsk.
  	 */
  	sctp_sock_migrate(sk, sock->sk, asoc, SCTP_SOCKET_UDP_HIGH_BANDWIDTH);
  
  	*sockp = sock;
  
  	return err;
  }
  
  static int sctp_getsockopt_peeloff(struct sock *sk, int len, char __user *optval, int __user *optlen)
  {
  	sctp_peeloff_arg_t peeloff;
  	struct socket *newsock;
  	int retval = 0;
  	struct sctp_association *asoc;
  
  	if (len < sizeof(sctp_peeloff_arg_t))
  		return -EINVAL;
  	len = sizeof(sctp_peeloff_arg_t);
  	if (copy_from_user(&peeloff, optval, len))
  		return -EFAULT;
  
  	asoc = sctp_id2assoc(sk, peeloff.associd);
  	if (!asoc) {
  		retval = -EINVAL;
  		goto out;
  	}
  
  	SCTP_DEBUG_PRINTK("%s: sk: %p asoc: %p\n", __func__, sk, asoc);
  
  	retval = sctp_do_peeloff(asoc, &newsock);
  	if (retval < 0)
  		goto out;
  
  	/* Map the socket to an unused fd that can be returned to the user.  */
  	retval = sock_map_fd(newsock, 0);
  	if (retval < 0) {
  		sock_release(newsock);
  		goto out;
  	}
  
  	SCTP_DEBUG_PRINTK("%s: sk: %p asoc: %p newsk: %p sd: %d\n",
  			  __func__, sk, asoc, newsock->sk, retval);
  
  	/* Return the fd mapped to the new socket.  */
  	peeloff.sd = retval;
  	if (put_user(len, optlen))
  		return -EFAULT;
  	if (copy_to_user(optval, &peeloff, len))
  		retval = -EFAULT;
  
  out:
  	return retval;
  }
  
  /* 7.1.13 Peer Address Parameters (SCTP_PEER_ADDR_PARAMS)
   *
   * Applications can enable or disable heartbeats for any peer address of
   * an association, modify an address's heartbeat interval, force a
   * heartbeat to be sent immediately, and adjust the address's maximum
   * number of retransmissions sent before an address is considered
   * unreachable.  The following structure is used to access and modify an
   * address's parameters:
   *
   *  struct sctp_paddrparams {
   *     sctp_assoc_t            spp_assoc_id;
   *     struct sockaddr_storage spp_address;
   *     uint32_t                spp_hbinterval;
   *     uint16_t                spp_pathmaxrxt;
   *     uint32_t                spp_pathmtu;
   *     uint32_t                spp_sackdelay;
   *     uint32_t                spp_flags;
   * };
   *
   *   spp_assoc_id    - (one-to-many style socket) This is filled in the
   *                     application, and identifies the association for
   *                     this query.
   *   spp_address     - This specifies which address is of interest.
   *   spp_hbinterval  - This contains the value of the heartbeat interval,
   *                     in milliseconds.  If a  value of zero
   *                     is present in this field then no changes are to
   *                     be made to this parameter.
   *   spp_pathmaxrxt  - This contains the maximum number of
   *                     retransmissions before this address shall be
   *                     considered unreachable. If a  value of zero
   *                     is present in this field then no changes are to
   *                     be made to this parameter.
   *   spp_pathmtu     - When Path MTU discovery is disabled the value
   *                     specified here will be the "fixed" path mtu.
   *                     Note that if the spp_address field is empty
   *                     then all associations on this address will
   *                     have this fixed path mtu set upon them.
   *
   *   spp_sackdelay   - When delayed sack is enabled, this value specifies
   *                     the number of milliseconds that sacks will be delayed
   *                     for. This value will apply to all addresses of an
   *                     association if the spp_address field is empty. Note
   *                     also, that if delayed sack is enabled and this
   *                     value is set to 0, no change is made to the last
   *                     recorded delayed sack timer value.
   *
   *   spp_flags       - These flags are used to control various features
   *                     on an association. The flag field may contain
   *                     zero or more of the following options.
   *
   *                     SPP_HB_ENABLE  - Enable heartbeats on the
   *                     specified address. Note that if the address
   *                     field is empty all addresses for the association
   *                     have heartbeats enabled upon them.
   *
   *                     SPP_HB_DISABLE - Disable heartbeats on the
   *                     speicifed address. Note that if the address
   *                     field is empty all addresses for the association
   *                     will have their heartbeats disabled. Note also
   *                     that SPP_HB_ENABLE and SPP_HB_DISABLE are
   *                     mutually exclusive, only one of these two should
   *                     be specified. Enabling both fields will have
   *                     undetermined results.
   *
   *                     SPP_HB_DEMAND - Request a user initiated heartbeat
   *                     to be made immediately.
   *
   *                     SPP_PMTUD_ENABLE - This field will enable PMTU
   *                     discovery upon the specified address. Note that
   *                     if the address feild is empty then all addresses
   *                     on the association are effected.
   *
   *                     SPP_PMTUD_DISABLE - This field will disable PMTU
   *                     discovery upon the specified address. Note that
   *                     if the address feild is empty then all addresses
   *                     on the association are effected. Not also that
   *                     SPP_PMTUD_ENABLE and SPP_PMTUD_DISABLE are mutually
   *                     exclusive. Enabling both will have undetermined
   *                     results.
   *
   *                     SPP_SACKDELAY_ENABLE - Setting this flag turns
   *                     on delayed sack. The time specified in spp_sackdelay
   *                     is used to specify the sack delay for this address. Note
   *                     that if spp_address is empty then all addresses will
   *                     enable delayed sack and take on the sack delay
   *                     value specified in spp_sackdelay.
   *                     SPP_SACKDELAY_DISABLE - Setting this flag turns
   *                     off delayed sack. If the spp_address field is blank then
   *                     delayed sack is disabled for the entire association. Note
   *                     also that this field is mutually exclusive to
   *                     SPP_SACKDELAY_ENABLE, setting both will have undefined
   *                     results.
   */
  static int sctp_getsockopt_peer_addr_params(struct sock *sk, int len,
  					    char __user *optval, int __user *optlen)
  {
  	struct sctp_paddrparams  params;
  	struct sctp_transport   *trans = NULL;
  	struct sctp_association *asoc = NULL;
  	struct sctp_sock        *sp = sctp_sk(sk);
  
  	if (len < sizeof(struct sctp_paddrparams))
  		return -EINVAL;
  	len = sizeof(struct sctp_paddrparams);
  	if (copy_from_user(&params, optval, len))
  		return -EFAULT;
  
  	/* If an address other than INADDR_ANY is specified, and
  	 * no transport is found, then the request is invalid.
  	 */
  	if (!sctp_is_any(sk, ( union sctp_addr *)&params.spp_address)) {
  		trans = sctp_addr_id2transport(sk, &params.spp_address,
  					       params.spp_assoc_id);
  		if (!trans) {
  			SCTP_DEBUG_PRINTK("Failed no transport\n");
  			return -EINVAL;
  		}
  	}
  
  	/* Get association, if assoc_id != 0 and the socket is a one
  	 * to many style socket, and an association was not found, then
  	 * the id was invalid.
  	 */
  	asoc = sctp_id2assoc(sk, params.spp_assoc_id);
  	if (!asoc && params.spp_assoc_id && sctp_style(sk, UDP)) {
  		SCTP_DEBUG_PRINTK("Failed no association\n");
  		return -EINVAL;
  	}
  
  	if (trans) {
  		/* Fetch transport values. */
  		params.spp_hbinterval = jiffies_to_msecs(trans->hbinterval);
  		params.spp_pathmtu    = trans->pathmtu;
  		params.spp_pathmaxrxt = trans->pathmaxrxt;
  		params.spp_sackdelay  = jiffies_to_msecs(trans->sackdelay);
  
  		/*draft-11 doesn't say what to return in spp_flags*/
  		params.spp_flags      = trans->param_flags;
  	} else if (asoc) {
  		/* Fetch association values. */
  		params.spp_hbinterval = jiffies_to_msecs(asoc->hbinterval);
  		params.spp_pathmtu    = asoc->pathmtu;
  		params.spp_pathmaxrxt = asoc->pathmaxrxt;
  		params.spp_sackdelay  = jiffies_to_msecs(asoc->sackdelay);
  
  		/*draft-11 doesn't say what to return in spp_flags*/
  		params.spp_flags      = asoc->param_flags;
  	} else {
  		/* Fetch socket values. */
  		params.spp_hbinterval = sp->hbinterval;
  		params.spp_pathmtu    = sp->pathmtu;
  		params.spp_sackdelay  = sp->sackdelay;
  		params.spp_pathmaxrxt = sp->pathmaxrxt;
  
  		/*draft-11 doesn't say what to return in spp_flags*/
  		params.spp_flags      = sp->param_flags;
  	}
  
  	if (copy_to_user(optval, &params, len))
  		return -EFAULT;
  
  	if (put_user(len, optlen))
  		return -EFAULT;
  
  	return 0;
  }
  
  /*
   * 7.1.23.  Get or set delayed ack timer (SCTP_DELAYED_SACK)
   *
   * This option will effect the way delayed acks are performed.  This
   * option allows you to get or set the delayed ack time, in
   * milliseconds.  It also allows changing the delayed ack frequency.
   * Changing the frequency to 1 disables the delayed sack algorithm.  If
   * the assoc_id is 0, then this sets or gets the endpoints default
   * values.  If the assoc_id field is non-zero, then the set or get
   * effects the specified association for the one to many model (the
   * assoc_id field is ignored by the one to one model).  Note that if
   * sack_delay or sack_freq are 0 when setting this option, then the
   * current values will remain unchanged.
   *
   * struct sctp_sack_info {
   *     sctp_assoc_t            sack_assoc_id;
   *     uint32_t                sack_delay;
   *     uint32_t                sack_freq;
   * };
   *
   * sack_assoc_id -  This parameter, indicates which association the user
   *    is performing an action upon.  Note that if this field's value is
   *    zero then the endpoints default value is changed (effecting future
   *    associations only).
   *
   * sack_delay -  This parameter contains the number of milliseconds that
   *    the user is requesting the delayed ACK timer be set to.  Note that
   *    this value is defined in the standard to be between 200 and 500
   *    milliseconds.
   *
   * sack_freq -  This parameter contains the number of packets that must
   *    be received before a sack is sent without waiting for the delay
   *    timer to expire.  The default value for this is 2, setting this
   *    value to 1 will disable the delayed sack algorithm.
   */
  static int sctp_getsockopt_delayed_ack(struct sock *sk, int len,
  					    char __user *optval,
  					    int __user *optlen)
  {
  	struct sctp_sack_info    params;
  	struct sctp_association *asoc = NULL;
  	struct sctp_sock        *sp = sctp_sk(sk);
  
  	if (len >= sizeof(struct sctp_sack_info)) {
  		len = sizeof(struct sctp_sack_info);
  
  		if (copy_from_user(&params, optval, len))
  			return -EFAULT;
  	} else if (len == sizeof(struct sctp_assoc_value)) {
  		printk(KERN_WARNING "SCTP: Use of struct sctp_assoc_value "
  		       "in delayed_ack socket option deprecated\n");
  		printk(KERN_WARNING "SCTP: Use struct sctp_sack_info instead\n");
  		if (copy_from_user(&params, optval, len))
  			return -EFAULT;
  	} else
  		return - EINVAL;
  
  	/* Get association, if sack_assoc_id != 0 and the socket is a one
  	 * to many style socket, and an association was not found, then
  	 * the id was invalid.
  	 */
  	asoc = sctp_id2assoc(sk, params.sack_assoc_id);
  	if (!asoc && params.sack_assoc_id && sctp_style(sk, UDP))
  		return -EINVAL;
  
  	if (asoc) {
  		/* Fetch association values. */
  		if (asoc->param_flags & SPP_SACKDELAY_ENABLE) {
  			params.sack_delay = jiffies_to_msecs(
  				asoc->sackdelay);
  			params.sack_freq = asoc->sackfreq;
  
  		} else {
  			params.sack_delay = 0;
  			params.sack_freq = 1;
  		}
  	} else {
  		/* Fetch socket values. */
  		if (sp->param_flags & SPP_SACKDELAY_ENABLE) {
  			params.sack_delay  = sp->sackdelay;
  			params.sack_freq = sp->sackfreq;
  		} else {
  			params.sack_delay  = 0;
  			params.sack_freq = 1;
  		}
  	}
  
  	if (copy_to_user(optval, &params, len))
  		return -EFAULT;
  
  	if (put_user(len, optlen))
  		return -EFAULT;
  
  	return 0;
  }
  
  /* 7.1.3 Initialization Parameters (SCTP_INITMSG)
   *
   * Applications can specify protocol parameters for the default association
   * initialization.  The option name argument to setsockopt() and getsockopt()
   * is SCTP_INITMSG.
   *
   * Setting initialization parameters is effective only on an unconnected
   * socket (for UDP-style sockets only future associations are effected
   * by the change).  With TCP-style sockets, this option is inherited by
   * sockets derived from a listener socket.
   */
  static int sctp_getsockopt_initmsg(struct sock *sk, int len, char __user *optval, int __user *optlen)
  {
  	if (len < sizeof(struct sctp_initmsg))
  		return -EINVAL;
  	len = sizeof(struct sctp_initmsg);
  	if (put_user(len, optlen))
  		return -EFAULT;
  	if (copy_to_user(optval, &sctp_sk(sk)->initmsg, len))
  		return -EFAULT;
  	return 0;
  }
  
  
  static int sctp_getsockopt_peer_addrs(struct sock *sk, int len,
  				      char __user *optval, int __user *optlen)
  {
  	struct sctp_association *asoc;
  	int cnt = 0;
  	struct sctp_getaddrs getaddrs;
  	struct sctp_transport *from;
  	void __user *to;
  	union sctp_addr temp;
  	struct sctp_sock *sp = sctp_sk(sk);
  	int addrlen;
  	size_t space_left;
  	int bytes_copied;
  
  	if (len < sizeof(struct sctp_getaddrs))
  		return -EINVAL;
  
  	if (copy_from_user(&getaddrs, optval, sizeof(struct sctp_getaddrs)))
  		return -EFAULT;
  
  	/* For UDP-style sockets, id specifies the association to query.  */
  	asoc = sctp_id2assoc(sk, getaddrs.assoc_id);
  	if (!asoc)
  		return -EINVAL;
  
  	to = optval + offsetof(struct sctp_getaddrs,addrs);
  	space_left = len - offsetof(struct sctp_getaddrs,addrs);
  
  	list_for_each_entry(from, &asoc->peer.transport_addr_list,
  				transports) {
  		memcpy(&temp, &from->ipaddr, sizeof(temp));
  		sctp_get_pf_specific(sk->sk_family)->addr_v4map(sp, &temp);
  		addrlen = sctp_get_af_specific(sk->sk_family)->sockaddr_len;
  		if (space_left < addrlen)
  			return -ENOMEM;
  		if (copy_to_user(to, &temp, addrlen))
  			return -EFAULT;
  		to += addrlen;
  		cnt++;
  		space_left -= addrlen;
  	}
  
  	if (put_user(cnt, &((struct sctp_getaddrs __user *)optval)->addr_num))
  		return -EFAULT;
  	bytes_copied = ((char __user *)to) - optval;
  	if (put_user(bytes_copied, optlen))
  		return -EFAULT;
  
  	return 0;
  }
  
  static int sctp_copy_laddrs(struct sock *sk, __u16 port, void *to,
  			    size_t space_left, int *bytes_copied)
  {
  	struct sctp_sockaddr_entry *addr;
  	union sctp_addr temp;
  	int cnt = 0;
  	int addrlen;
  
  	rcu_read_lock();
  	list_for_each_entry_rcu(addr, &sctp_local_addr_list, list) {
  		if (!addr->valid)
  			continue;
  
  		if ((PF_INET == sk->sk_family) &&
  		    (AF_INET6 == addr->a.sa.sa_family))
  			continue;
  		if ((PF_INET6 == sk->sk_family) &&
  		    inet_v6_ipv6only(sk) &&
  		    (AF_INET == addr->a.sa.sa_family))
  			continue;
  		memcpy(&temp, &addr->a, sizeof(temp));
  		if (!temp.v4.sin_port)
  			temp.v4.sin_port = htons(port);
  
  		sctp_get_pf_specific(sk->sk_family)->addr_v4map(sctp_sk(sk),
  								&temp);
  		addrlen = sctp_get_af_specific(temp.sa.sa_family)->sockaddr_len;
  		if (space_left < addrlen) {
  			cnt =  -ENOMEM;
  			break;
  		}
  		memcpy(to, &temp, addrlen);
  
  		to += addrlen;
  		cnt ++;
  		space_left -= addrlen;
  		*bytes_copied += addrlen;
  	}
  	rcu_read_unlock();
  
  	return cnt;
  }
  
  
  static int sctp_getsockopt_local_addrs(struct sock *sk, int len,
  				       char __user *optval, int __user *optlen)
  {
  	struct sctp_bind_addr *bp;
  	struct sctp_association *asoc;
  	int cnt = 0;
  	struct sctp_getaddrs getaddrs;
  	struct sctp_sockaddr_entry *addr;
  	void __user *to;
  	union sctp_addr temp;
  	struct sctp_sock *sp = sctp_sk(sk);
  	int addrlen;
  	int err = 0;
  	size_t space_left;
  	int bytes_copied = 0;
  	void *addrs;
  	void *buf;
  
  	if (len < sizeof(struct sctp_getaddrs))
  		return -EINVAL;
  
  	if (copy_from_user(&getaddrs, optval, sizeof(struct sctp_getaddrs)))
  		return -EFAULT;
  
  	/*
  	 *  For UDP-style sockets, id specifies the association to query.
  	 *  If the id field is set to the value '0' then the locally bound
  	 *  addresses are returned without regard to any particular
  	 *  association.
  	 */
  	if (0 == getaddrs.assoc_id) {
  		bp = &sctp_sk(sk)->ep->base.bind_addr;
  	} else {
  		asoc = sctp_id2assoc(sk, getaddrs.assoc_id);
  		if (!asoc)
  			return -EINVAL;
  		bp = &asoc->base.bind_addr;
  	}
  
  	to = optval + offsetof(struct sctp_getaddrs,addrs);
  	space_left = len - offsetof(struct sctp_getaddrs,addrs);
  
  	addrs = kmalloc(space_left, GFP_KERNEL);
  	if (!addrs)
  		return -ENOMEM;
  
  	/* If the endpoint is bound to 0.0.0.0 or ::0, get the valid
  	 * addresses from the global local address list.
  	 */
  	if (sctp_list_single_entry(&bp->address_list)) {
  		addr = list_entry(bp->address_list.next,
  				  struct sctp_sockaddr_entry, list);
  		if (sctp_is_any(sk, &addr->a)) {
  			cnt = sctp_copy_laddrs(sk, bp->port, addrs,
  						space_left, &bytes_copied);
  			if (cnt < 0) {
  				err = cnt;
  				goto out;
  			}
  			goto copy_getaddrs;
  		}
  	}
  
  	buf = addrs;
  	/* Protection on the bound address list is not needed since
  	 * in the socket option context we hold a socket lock and
  	 * thus the bound address list can't change.
  	 */
  	list_for_each_entry(addr, &bp->address_list, list) {
  		memcpy(&temp, &addr->a, sizeof(temp));
  		sctp_get_pf_specific(sk->sk_family)->addr_v4map(sp, &temp);
  		addrlen = sctp_get_af_specific(temp.sa.sa_family)->sockaddr_len;
  		if (space_left < addrlen) {
  			err =  -ENOMEM; /*fixme: right error?*/
  			goto out;
  		}
  		memcpy(buf, &temp, addrlen);
  		buf += addrlen;
  		bytes_copied += addrlen;
  		cnt ++;
  		space_left -= addrlen;
  	}
  
  copy_getaddrs:
  	if (copy_to_user(to, addrs, bytes_copied)) {
  		err = -EFAULT;
  		goto out;
  	}
  	if (put_user(cnt, &((struct sctp_getaddrs __user *)optval)->addr_num)) {
  		err = -EFAULT;
  		goto out;
  	}
  	if (put_user(bytes_copied, optlen))
  		err = -EFAULT;
  out:
  	kfree(addrs);
  	return err;
  }
  
  /* 7.1.10 Set Primary Address (SCTP_PRIMARY_ADDR)
   *
   * Requests that the local SCTP stack use the enclosed peer address as
   * the association primary.  The enclosed address must be one of the
   * association peer's addresses.
   */
  static int sctp_getsockopt_primary_addr(struct sock *sk, int len,
  					char __user *optval, int __user *optlen)
  {
  	struct sctp_prim prim;
  	struct sctp_association *asoc;
  	struct sctp_sock *sp = sctp_sk(sk);
  
  	if (len < sizeof(struct sctp_prim))
  		return -EINVAL;
  
  	len = sizeof(struct sctp_prim);
  
  	if (copy_from_user(&prim, optval, len))
  		return -EFAULT;
  
  	asoc = sctp_id2assoc(sk, prim.ssp_assoc_id);
  	if (!asoc)
  		return -EINVAL;
  
  	if (!asoc->peer.primary_path)
  		return -ENOTCONN;
  
  	memcpy(&prim.ssp_addr, &asoc->peer.primary_path->ipaddr,
  		asoc->peer.primary_path->af_specific->sockaddr_len);
  
  	sctp_get_pf_specific(sk->sk_family)->addr_v4map(sp,
  			(union sctp_addr *)&prim.ssp_addr);
  
  	if (put_user(len, optlen))
  		return -EFAULT;
  	if (copy_to_user(optval, &prim, len))
  		return -EFAULT;
  
  	return 0;
  }
  
  /*
   * 7.1.11  Set Adaptation Layer Indicator (SCTP_ADAPTATION_LAYER)
   *
   * Requests that the local endpoint set the specified Adaptation Layer
   * Indication parameter for all future INIT and INIT-ACK exchanges.
   */
  static int sctp_getsockopt_adaptation_layer(struct sock *sk, int len,
  				  char __user *optval, int __user *optlen)
  {
  	struct sctp_setadaptation adaptation;
  
  	if (len < sizeof(struct sctp_setadaptation))
  		return -EINVAL;
  
  	len = sizeof(struct sctp_setadaptation);
  
  	adaptation.ssb_adaptation_ind = sctp_sk(sk)->adaptation_ind;
  
  	if (put_user(len, optlen))
  		return -EFAULT;
  	if (copy_to_user(optval, &adaptation, len))
  		return -EFAULT;
  
  	return 0;
  }
  
  /*
   *
   * 7.1.14 Set default send parameters (SCTP_DEFAULT_SEND_PARAM)
   *
   *   Applications that wish to use the sendto() system call may wish to
   *   specify a default set of parameters that would normally be supplied
   *   through the inclusion of ancillary data.  This socket option allows
   *   such an application to set the default sctp_sndrcvinfo structure.
  
  
   *   The application that wishes to use this socket option simply passes
   *   in to this call the sctp_sndrcvinfo structure defined in Section
   *   5.2.2) The input parameters accepted by this call include
   *   sinfo_stream, sinfo_flags, sinfo_ppid, sinfo_context,
   *   sinfo_timetolive.  The user must provide the sinfo_assoc_id field in
   *   to this call if the caller is using the UDP model.
   *
   *   For getsockopt, it get the default sctp_sndrcvinfo structure.
   */
  static int sctp_getsockopt_default_send_param(struct sock *sk,
  					int len, char __user *optval,
  					int __user *optlen)
  {
  	struct sctp_sndrcvinfo info;
  	struct sctp_association *asoc;
  	struct sctp_sock *sp = sctp_sk(sk);
  
  	if (len < sizeof(struct sctp_sndrcvinfo))
  		return -EINVAL;
  
  	len = sizeof(struct sctp_sndrcvinfo);
  
  	if (copy_from_user(&info, optval, len))
  		return -EFAULT;
  
  	asoc = sctp_id2assoc(sk, info.sinfo_assoc_id);
  	if (!asoc && info.sinfo_assoc_id && sctp_style(sk, UDP))
  		return -EINVAL;
  
  	if (asoc) {
  		info.sinfo_stream = asoc->default_stream;
  		info.sinfo_flags = asoc->default_flags;
  		info.sinfo_ppid = asoc->default_ppid;
  		info.sinfo_context = asoc->default_context;
  		info.sinfo_timetolive = asoc->default_timetolive;
  	} else {
  		info.sinfo_stream = sp->default_stream;
  		info.sinfo_flags = sp->default_flags;
  		info.sinfo_ppid = sp->default_ppid;
  		info.sinfo_context = sp->default_context;
  		info.sinfo_timetolive = sp->default_timetolive;
  	}
  
  	if (put_user(len, optlen))
  		return -EFAULT;
  	if (copy_to_user(optval, &info, len))
  		return -EFAULT;
  
  	return 0;
  }
  
  /*
   *
   * 7.1.5 SCTP_NODELAY
   *
   * Turn on/off any Nagle-like algorithm.  This means that packets are
   * generally sent as soon as possible and no unnecessary delays are
   * introduced, at the cost of more packets in the network.  Expects an
   * integer boolean flag.
   */
  
  static int sctp_getsockopt_nodelay(struct sock *sk, int len,
  				   char __user *optval, int __user *optlen)
  {
  	int val;
  
  	if (len < sizeof(int))
  		return -EINVAL;
  
  	len = sizeof(int);
  	val = (sctp_sk(sk)->nodelay == 1);
  	if (put_user(len, optlen))
  		return -EFAULT;
  	if (copy_to_user(optval, &val, len))
  		return -EFAULT;
  	return 0;
  }
  
  /*
   *
   * 7.1.1 SCTP_RTOINFO
   *
   * The protocol parameters used to initialize and bound retransmission
   * timeout (RTO) are tunable. sctp_rtoinfo structure is used to access
   * and modify these parameters.
   * All parameters are time values, in milliseconds.  A value of 0, when
   * modifying the parameters, indicates that the current value should not
   * be changed.
   *
   */
  static int sctp_getsockopt_rtoinfo(struct sock *sk, int len,
  				char __user *optval,
  				int __user *optlen) {
  	struct sctp_rtoinfo rtoinfo;
  	struct sctp_association *asoc;
  
  	if (len < sizeof (struct sctp_rtoinfo))
  		return -EINVAL;
  
  	len = sizeof(struct sctp_rtoinfo);
  
  	if (copy_from_user(&rtoinfo, optval, len))
  		return -EFAULT;
  
  	asoc = sctp_id2assoc(sk, rtoinfo.srto_assoc_id);
  
  	if (!asoc && rtoinfo.srto_assoc_id && sctp_style(sk, UDP))
  		return -EINVAL;
  
  	/* Values corresponding to the specific association. */
  	if (asoc) {
  		rtoinfo.srto_initial = jiffies_to_msecs(asoc->rto_initial);
  		rtoinfo.srto_max = jiffies_to_msecs(asoc->rto_max);
  		rtoinfo.srto_min = jiffies_to_msecs(asoc->rto_min);
  	} else {
  		/* Values corresponding to the endpoint. */
  		struct sctp_sock *sp = sctp_sk(sk);
  
  		rtoinfo.srto_initial = sp->rtoinfo.srto_initial;
  		rtoinfo.srto_max = sp->rtoinfo.srto_max;
  		rtoinfo.srto_min = sp->rtoinfo.srto_min;
  	}
  
  	if (put_user(len, optlen))
  		return -EFAULT;
  
  	if (copy_to_user(optval, &rtoinfo, len))
  		return -EFAULT;
  
  	return 0;
  }
  
  /*
   *
   * 7.1.2 SCTP_ASSOCINFO
   *
   * This option is used to tune the maximum retransmission attempts
   * of the association.
   * Returns an error if the new association retransmission value is
   * greater than the sum of the retransmission value  of the peer.
   * See [SCTP] for more information.
   *
   */
  static int sctp_getsockopt_associnfo(struct sock *sk, int len,
  				     char __user *optval,
  				     int __user *optlen)
  {
  
  	struct sctp_assocparams assocparams;
  	struct sctp_association *asoc;
  	struct list_head *pos;
  	int cnt = 0;
  
  	if (len < sizeof (struct sctp_assocparams))
  		return -EINVAL;
  
  	len = sizeof(struct sctp_assocparams);
  
  	if (copy_from_user(&assocparams, optval, len))
  		return -EFAULT;
  
  	asoc = sctp_id2assoc(sk, assocparams.sasoc_assoc_id);
  
  	if (!asoc && assocparams.sasoc_assoc_id && sctp_style(sk, UDP))
  		return -EINVAL;
  
  	/* Values correspoinding to the specific association */
  	if (asoc) {
  		assocparams.sasoc_asocmaxrxt = asoc->max_retrans;
  		assocparams.sasoc_peer_rwnd = asoc->peer.rwnd;
  		assocparams.sasoc_local_rwnd = asoc->a_rwnd;
  		assocparams.sasoc_cookie_life = (asoc->cookie_life.tv_sec
  						* 1000) +
  						(asoc->cookie_life.tv_usec
  						/ 1000);
  
  		list_for_each(pos, &asoc->peer.transport_addr_list) {
  			cnt ++;
  		}
  
  		assocparams.sasoc_number_peer_destinations = cnt;
  	} else {
  		/* Values corresponding to the endpoint */
  		struct sctp_sock *sp = sctp_sk(sk);
  
  		assocparams.sasoc_asocmaxrxt = sp->assocparams.sasoc_asocmaxrxt;
  		assocparams.sasoc_peer_rwnd = sp->assocparams.sasoc_peer_rwnd;
  		assocparams.sasoc_local_rwnd = sp->assocparams.sasoc_local_rwnd;
  		assocparams.sasoc_cookie_life =
  					sp->assocparams.sasoc_cookie_life;
  		assocparams.sasoc_number_peer_destinations =
  					sp->assocparams.
  					sasoc_number_peer_destinations;
  	}
  
  	if (put_user(len, optlen))
  		return -EFAULT;
  
  	if (copy_to_user(optval, &assocparams, len))
  		return -EFAULT;
  
  	return 0;
  }
  
  /*
   * 7.1.16 Set/clear IPv4 mapped addresses (SCTP_I_WANT_MAPPED_V4_ADDR)
   *
   * This socket option is a boolean flag which turns on or off mapped V4
   * addresses.  If this option is turned on and the socket is type
   * PF_INET6, then IPv4 addresses will be mapped to V6 representation.
   * If this option is turned off, then no mapping will be done of V4
   * addresses and a user will receive both PF_INET6 and PF_INET type
   * addresses on the socket.
   */
  static int sctp_getsockopt_mappedv4(struct sock *sk, int len,
  				    char __user *optval, int __user *optlen)
  {
  	int val;
  	struct sctp_sock *sp = sctp_sk(sk);
  
  	if (len < sizeof(int))
  		return -EINVAL;
  
  	len = sizeof(int);
  	val = sp->v4mapped;
  	if (put_user(len, optlen))
  		return -EFAULT;
  	if (copy_to_user(optval, &val, len))
  		return -EFAULT;
  
  	return 0;
  }
  
  /*
   * 7.1.29.  Set or Get the default context (SCTP_CONTEXT)
   * (chapter and verse is quoted at sctp_setsockopt_context())
   */
  static int sctp_getsockopt_context(struct sock *sk, int len,
  				   char __user *optval, int __user *optlen)
  {
  	struct sctp_assoc_value params;
  	struct sctp_sock *sp;
  	struct sctp_association *asoc;
  
  	if (len < sizeof(struct sctp_assoc_value))
  		return -EINVAL;
  
  	len = sizeof(struct sctp_assoc_value);
  
  	if (copy_from_user(&params, optval, len))
  		return -EFAULT;
  
  	sp = sctp_sk(sk);
  
  	if (params.assoc_id != 0) {
  		asoc = sctp_id2assoc(sk, params.assoc_id);
  		if (!asoc)
  			return -EINVAL;
  		params.assoc_value = asoc->default_rcv_context;
  	} else {
  		params.assoc_value = sp->default_rcv_context;
  	}
  
  	if (put_user(len, optlen))
  		return -EFAULT;
  	if (copy_to_user(optval, &params, len))
  		return -EFAULT;
  
  	return 0;
  }
  
  /*
   * 8.1.16.  Get or Set the Maximum Fragmentation Size (SCTP_MAXSEG)
   * This option will get or set the maximum size to put in any outgoing
   * SCTP DATA chunk.  If a message is larger than this size it will be
   * fragmented by SCTP into the specified size.  Note that the underlying
   * SCTP implementation may fragment into smaller sized chunks when the
   * PMTU of the underlying association is smaller than the value set by
   * the user.  The default value for this option is '0' which indicates
   * the user is NOT limiting fragmentation and only the PMTU will effect
   * SCTP's choice of DATA chunk size.  Note also that values set larger
   * than the maximum size of an IP datagram will effectively let SCTP
   * control fragmentation (i.e. the same as setting this option to 0).
   *
   * The following structure is used to access and modify this parameter:
   *
   * struct sctp_assoc_value {
   *   sctp_assoc_t assoc_id;
   *   uint32_t assoc_value;
   * };
   *
   * assoc_id:  This parameter is ignored for one-to-one style sockets.
   *    For one-to-many style sockets this parameter indicates which
   *    association the user is performing an action upon.  Note that if
   *    this field's value is zero then the endpoints default value is
   *    changed (effecting future associations only).
   * assoc_value:  This parameter specifies the maximum size in bytes.
   */
  static int sctp_getsockopt_maxseg(struct sock *sk, int len,
  				  char __user *optval, int __user *optlen)
  {
  	struct sctp_assoc_value params;
  	struct sctp_association *asoc;
  
  	if (len == sizeof(int)) {
  		printk(KERN_WARNING
  		   "SCTP: Use of int in maxseg socket option deprecated\n");
  		printk(KERN_WARNING
  		   "SCTP: Use struct sctp_assoc_value instead\n");
  		params.assoc_id = 0;
  	} else if (len >= sizeof(struct sctp_assoc_value)) {
  		len = sizeof(struct sctp_assoc_value);
  		if (copy_from_user(&params, optval, sizeof(params)))
  			return -EFAULT;
  	} else
  		return -EINVAL;
  
  	asoc = sctp_id2assoc(sk, params.assoc_id);
  	if (!asoc && params.assoc_id && sctp_style(sk, UDP))
  		return -EINVAL;
  
  	if (asoc)
  		params.assoc_value = asoc->frag_point;
  	else
  		params.assoc_value = sctp_sk(sk)->user_frag;
  
  	if (put_user(len, optlen))
  		return -EFAULT;
  	if (len == sizeof(int)) {
  		if (copy_to_user(optval, &params.assoc_value, len))
  			return -EFAULT;
  	} else {
  		if (copy_to_user(optval, &params, len))
  			return -EFAULT;
  	}
  
  	return 0;
  }
  
  /*
   * 7.1.24.  Get or set fragmented interleave (SCTP_FRAGMENT_INTERLEAVE)
   * (chapter and verse is quoted at sctp_setsockopt_fragment_interleave())
   */
  static int sctp_getsockopt_fragment_interleave(struct sock *sk, int len,
  					       char __user *optval, int __user *optlen)
  {
  	int val;
  
  	if (len < sizeof(int))
  		return -EINVAL;
  
  	len = sizeof(int);
  
  	val = sctp_sk(sk)->frag_interleave;
  	if (put_user(len, optlen))
  		return -EFAULT;
  	if (copy_to_user(optval, &val, len))
  		return -EFAULT;
  
  	return 0;
  }
  
  /*
   * 7.1.25.  Set or Get the sctp partial delivery point
   * (chapter and verse is quoted at sctp_setsockopt_partial_delivery_point())
   */
  static int sctp_getsockopt_partial_delivery_point(struct sock *sk, int len,
  						  char __user *optval,
  						  int __user *optlen)
  {
  	u32 val;
  
  	if (len < sizeof(u32))
  		return -EINVAL;
  
  	len = sizeof(u32);
  
  	val = sctp_sk(sk)->pd_point;
  	if (put_user(len, optlen))
  		return -EFAULT;
  	if (copy_to_user(optval, &val, len))
  		return -EFAULT;
  
  	return -ENOTSUPP;
  }
  
  /*
   * 7.1.28.  Set or Get the maximum burst (SCTP_MAX_BURST)
   * (chapter and verse is quoted at sctp_setsockopt_maxburst())
   */
  static int sctp_getsockopt_maxburst(struct sock *sk, int len,
  				    char __user *optval,
  				    int __user *optlen)
  {
  	struct sctp_assoc_value params;
  	struct sctp_sock *sp;
  	struct sctp_association *asoc;
  
  	if (len == sizeof(int)) {
  		printk(KERN_WARNING
  		   "SCTP: Use of int in max_burst socket option deprecated\n");
  		printk(KERN_WARNING
  		   "SCTP: Use struct sctp_assoc_value instead\n");
  		params.assoc_id = 0;
  	} else if (len >= sizeof(struct sctp_assoc_value)) {
  		len = sizeof(struct sctp_assoc_value);
  		if (copy_from_user(&params, optval, len))
  			return -EFAULT;
  	} else
  		return -EINVAL;
  
  	sp = sctp_sk(sk);
  
  	if (params.assoc_id != 0) {
  		asoc = sctp_id2assoc(sk, params.assoc_id);
  		if (!asoc)
  			return -EINVAL;
  		params.assoc_value = asoc->max_burst;
  	} else
  		params.assoc_value = sp->max_burst;
  
  	if (len == sizeof(int)) {
  		if (copy_to_user(optval, &params.assoc_value, len))
  			return -EFAULT;
  	} else {
  		if (copy_to_user(optval, &params, len))
  			return -EFAULT;
  	}
  
  	return 0;
  
  }
  
  static int sctp_getsockopt_hmac_ident(struct sock *sk, int len,
  				    char __user *optval, int __user *optlen)
  {
  	struct sctp_hmacalgo  __user *p = (void __user *)optval;
  	struct sctp_hmac_algo_param *hmacs;
  	__u16 data_len = 0;
  	u32 num_idents;
  
  	if (!sctp_auth_enable)
  		return -EACCES;
  
  	hmacs = sctp_sk(sk)->ep->auth_hmacs_list;
  	data_len = ntohs(hmacs->param_hdr.length) - sizeof(sctp_paramhdr_t);
  
  	if (len < sizeof(struct sctp_hmacalgo) + data_len)
  		return -EINVAL;
  
  	len = sizeof(struct sctp_hmacalgo) + data_len;
  	num_idents = data_len / sizeof(u16);
  
  	if (put_user(len, optlen))
  		return -EFAULT;
  	if (put_user(num_idents, &p->shmac_num_idents))
  		return -EFAULT;
  	if (copy_to_user(p->shmac_idents, hmacs->hmac_ids, data_len))
  		return -EFAULT;
  	return 0;
  }
  
  static int sctp_getsockopt_active_key(struct sock *sk, int len,
  				    char __user *optval, int __user *optlen)
  {
  	struct sctp_authkeyid val;
  	struct sctp_association *asoc;
  
  	if (!sctp_auth_enable)
  		return -EACCES;
  
  	if (len < sizeof(struct sctp_authkeyid))
  		return -EINVAL;
  	if (copy_from_user(&val, optval, sizeof(struct sctp_authkeyid)))
  		return -EFAULT;
  
  	asoc = sctp_id2assoc(sk, val.scact_assoc_id);
  	if (!asoc && val.scact_assoc_id && sctp_style(sk, UDP))
  		return -EINVAL;
  
  	if (asoc)
  		val.scact_keynumber = asoc->active_key_id;
  	else
  		val.scact_keynumber = sctp_sk(sk)->ep->active_key_id;
  
  	len = sizeof(struct sctp_authkeyid);
  	if (put_user(len, optlen))
  		return -EFAULT;
  	if (copy_to_user(optval, &val, len))
  		return -EFAULT;
  
  	return 0;
  }
  
  static int sctp_getsockopt_peer_auth_chunks(struct sock *sk, int len,
  				    char __user *optval, int __user *optlen)
  {
  	struct sctp_authchunks __user *p = (void __user *)optval;
  	struct sctp_authchunks val;
  	struct sctp_association *asoc;
  	struct sctp_chunks_param *ch;
  	u32    num_chunks = 0;
  	char __user *to;
  
  	if (!sctp_auth_enable)
  		return -EACCES;
  
  	if (len < sizeof(struct sctp_authchunks))
  		return -EINVAL;
  
  	if (copy_from_user(&val, optval, sizeof(struct sctp_authchunks)))
  		return -EFAULT;
  
  	to = p->gauth_chunks;
  	asoc = sctp_id2assoc(sk, val.gauth_assoc_id);
  	if (!asoc)
  		return -EINVAL;
  
  	ch = asoc->peer.peer_chunks;
  	if (!ch)
  		goto num;
  
  	/* See if the user provided enough room for all the data */
  	num_chunks = ntohs(ch->param_hdr.length) - sizeof(sctp_paramhdr_t);
  	if (len < num_chunks)
  		return -EINVAL;
  
  	if (copy_to_user(to, ch->chunks, num_chunks))
  		return -EFAULT;
  num:
  	len = sizeof(struct sctp_authchunks) + num_chunks;
  	if (put_user(len, optlen)) return -EFAULT;
  	if (put_user(num_chunks, &p->gauth_number_of_chunks))
  		return -EFAULT;
  	return 0;
  }
  
  static int sctp_getsockopt_local_auth_chunks(struct sock *sk, int len,
  				    char __user *optval, int __user *optlen)
  {
  	struct sctp_authchunks __user *p = (void __user *)optval;
  	struct sctp_authchunks val;
  	struct sctp_association *asoc;
  	struct sctp_chunks_param *ch;
  	u32    num_chunks = 0;
  	char __user *to;
  
  	if (!sctp_auth_enable)
  		return -EACCES;
  
  	if (len < sizeof(struct sctp_authchunks))
  		return -EINVAL;
  
  	if (copy_from_user(&val, optval, sizeof(struct sctp_authchunks)))
  		return -EFAULT;
  
  	to = p->gauth_chunks;
  	asoc = sctp_id2assoc(sk, val.gauth_assoc_id);
  	if (!asoc && val.gauth_assoc_id && sctp_style(sk, UDP))
  		return -EINVAL;
  
  	if (asoc)
  		ch = (struct sctp_chunks_param*)asoc->c.auth_chunks;
  	else
  		ch = sctp_sk(sk)->ep->auth_chunk_list;
  
  	if (!ch)
  		goto num;
  
  	num_chunks = ntohs(ch->param_hdr.length) - sizeof(sctp_paramhdr_t);
  	if (len < sizeof(struct sctp_authchunks) + num_chunks)
  		return -EINVAL;
  
  	if (copy_to_user(to, ch->chunks, num_chunks))
  		return -EFAULT;
  num:
  	len = sizeof(struct sctp_authchunks) + num_chunks;
  	if (put_user(len, optlen))
  		return -EFAULT;
  	if (put_user(num_chunks, &p->gauth_number_of_chunks))
  		return -EFAULT;
  
  	return 0;
  }
  
  /*
   * 8.2.5.  Get the Current Number of Associations (SCTP_GET_ASSOC_NUMBER)
   * This option gets the current number of associations that are attached
   * to a one-to-many style socket.  The option value is an uint32_t.
   */
  static int sctp_getsockopt_assoc_number(struct sock *sk, int len,
  				    char __user *optval, int __user *optlen)
  {
  	struct sctp_sock *sp = sctp_sk(sk);
  	struct sctp_association *asoc;
  	u32 val = 0;
  
  	if (sctp_style(sk, TCP))
  		return -EOPNOTSUPP;
  
  	if (len < sizeof(u32))
  		return -EINVAL;
  
  	len = sizeof(u32);
  
  	list_for_each_entry(asoc, &(sp->ep->asocs), asocs) {
  		val++;
  	}
  
  	if (put_user(len, optlen))
  		return -EFAULT;
  	if (copy_to_user(optval, &val, len))
  		return -EFAULT;
  
  	return 0;
  }
  
  SCTP_STATIC int sctp_getsockopt(struct sock *sk, int level, int optname,
  				char __user *optval, int __user *optlen)
  {
  	int retval = 0;
  	int len;
  
  	SCTP_DEBUG_PRINTK("sctp_getsockopt(sk: %p... optname: %d)\n",
  			  sk, optname);
  
  	/* I can hardly begin to describe how wrong this is.  This is
  	 * so broken as to be worse than useless.  The API draft
  	 * REALLY is NOT helpful here...  I am not convinced that the
  	 * semantics of getsockopt() with a level OTHER THAN SOL_SCTP
  	 * are at all well-founded.
  	 */
  	if (level != SOL_SCTP) {
  		struct sctp_af *af = sctp_sk(sk)->pf->af;
  
  		retval = af->getsockopt(sk, level, optname, optval, optlen);
  		return retval;
  	}
  
  	if (get_user(len, optlen))
  		return -EFAULT;
  
  	sctp_lock_sock(sk);
  
  	switch (optname) {
  	case SCTP_STATUS:
  		retval = sctp_getsockopt_sctp_status(sk, len, optval, optlen);
  		break;
  	case SCTP_DISABLE_FRAGMENTS:
  		retval = sctp_getsockopt_disable_fragments(sk, len, optval,
  							   optlen);
  		break;
  	case SCTP_EVENTS:
  		retval = sctp_getsockopt_events(sk, len, optval, optlen);
  		break;
  	case SCTP_AUTOCLOSE:
  		retval = sctp_getsockopt_autoclose(sk, len, optval, optlen);
  		break;
  	case SCTP_SOCKOPT_PEELOFF:
  		retval = sctp_getsockopt_peeloff(sk, len, optval, optlen);
  		break;
  	case SCTP_PEER_ADDR_PARAMS:
  		retval = sctp_getsockopt_peer_addr_params(sk, len, optval,
  							  optlen);
  		break;
  	case SCTP_DELAYED_ACK:
  		retval = sctp_getsockopt_delayed_ack(sk, len, optval,
  							  optlen);
  		break;
  	case SCTP_INITMSG:
  		retval = sctp_getsockopt_initmsg(sk, len, optval, optlen);
  		break;
  	case SCTP_GET_PEER_ADDRS:
  		retval = sctp_getsockopt_peer_addrs(sk, len, optval,
  						    optlen);
  		break;
  	case SCTP_GET_LOCAL_ADDRS:
  		retval = sctp_getsockopt_local_addrs(sk, len, optval,
  						     optlen);
  		break;
  	case SCTP_SOCKOPT_CONNECTX3:
  		retval = sctp_getsockopt_connectx3(sk, len, optval, optlen);
  		break;
  	case SCTP_DEFAULT_SEND_PARAM:
  		retval = sctp_getsockopt_default_send_param(sk, len,
  							    optval, optlen);
  		break;
  	case SCTP_PRIMARY_ADDR:
  		retval = sctp_getsockopt_primary_addr(sk, len, optval, optlen);
  		break;
  	case SCTP_NODELAY:
  		retval = sctp_getsockopt_nodelay(sk, len, optval, optlen);
  		break;
  	case SCTP_RTOINFO:
  		retval = sctp_getsockopt_rtoinfo(sk, len, optval, optlen);
  		break;
  	case SCTP_ASSOCINFO:
  		retval = sctp_getsockopt_associnfo(sk, len, optval, optlen);
  		break;
  	case SCTP_I_WANT_MAPPED_V4_ADDR:
  		retval = sctp_getsockopt_mappedv4(sk, len, optval, optlen);
  		break;
  	case SCTP_MAXSEG:
  		retval = sctp_getsockopt_maxseg(sk, len, optval, optlen);
  		break;
  	case SCTP_GET_PEER_ADDR_INFO:
  		retval = sctp_getsockopt_peer_addr_info(sk, len, optval,
  							optlen);
  		break;
  	case SCTP_ADAPTATION_LAYER:
  		retval = sctp_getsockopt_adaptation_layer(sk, len, optval,
  							optlen);
  		break;
  	case SCTP_CONTEXT:
  		retval = sctp_getsockopt_context(sk, len, optval, optlen);
  		break;
  	case SCTP_FRAGMENT_INTERLEAVE:
  		retval = sctp_getsockopt_fragment_interleave(sk, len, optval,
  							     optlen);
  		break;
  	case SCTP_PARTIAL_DELIVERY_POINT:
  		retval = sctp_getsockopt_partial_delivery_point(sk, len, optval,
  								optlen);
  		break;
  	case SCTP_MAX_BURST:
  		retval = sctp_getsockopt_maxburst(sk, len, optval, optlen);
  		break;
  	case SCTP_AUTH_KEY:
  	case SCTP_AUTH_CHUNK:
  	case SCTP_AUTH_DELETE_KEY:
  		retval = -EOPNOTSUPP;
  		break;
  	case SCTP_HMAC_IDENT:
  		retval = sctp_getsockopt_hmac_ident(sk, len, optval, optlen);
  		break;
  	case SCTP_AUTH_ACTIVE_KEY:
  		retval = sctp_getsockopt_active_key(sk, len, optval, optlen);
  		break;
  	case SCTP_PEER_AUTH_CHUNKS:
  		retval = sctp_getsockopt_peer_auth_chunks(sk, len, optval,
  							optlen);
  		break;
  	case SCTP_LOCAL_AUTH_CHUNKS:
  		retval = sctp_getsockopt_local_auth_chunks(sk, len, optval,
  							optlen);
  		break;
  	case SCTP_GET_ASSOC_NUMBER:
  		retval = sctp_getsockopt_assoc_number(sk, len, optval, optlen);
  		break;
  	default:
  		retval = -ENOPROTOOPT;
  		break;
  	}
  
  	sctp_release_sock(sk);
  	return retval;
  }
  
  static void sctp_hash(struct sock *sk)
  {
  	/* STUB */
  }
  
  static void sctp_unhash(struct sock *sk)
  {
  	/* STUB */
  }
  
  /* Check if port is acceptable.  Possibly find first available port.
   *
   * The port hash table (contained in the 'global' SCTP protocol storage
   * returned by struct sctp_protocol *sctp_get_protocol()). The hash
   * table is an array of 4096 lists (sctp_bind_hashbucket). Each
   * list (the list number is the port number hashed out, so as you
   * would expect from a hash function, all the ports in a given list have
   * such a number that hashes out to the same list number; you were
   * expecting that, right?); so each list has a set of ports, with a
   * link to the socket (struct sock) that uses it, the port number and
   * a fastreuse flag (FIXME: NPI ipg).
   */
  static struct sctp_bind_bucket *sctp_bucket_create(
  	struct sctp_bind_hashbucket *head, unsigned short snum);
  
  static long sctp_get_port_local(struct sock *sk, union sctp_addr *addr)
  {
  	struct sctp_bind_hashbucket *head; /* hash list */
  	struct sctp_bind_bucket *pp; /* hash list port iterator */
  	struct hlist_node *node;
  	unsigned short snum;
  	int ret;
  
  	snum = ntohs(addr->v4.sin_port);
  
  	SCTP_DEBUG_PRINTK("sctp_get_port() begins, snum=%d\n", snum);
  	sctp_local_bh_disable();
  
  	if (snum == 0) {
  		/* Search for an available port. */
  		int low, high, remaining, index;
  		unsigned int rover;
  
  		inet_get_local_port_range(&low, &high);
  		remaining = (high - low) + 1;
  		rover = net_random() % remaining + low;
  
  		do {
  			rover++;
  			if ((rover < low) || (rover > high))
  				rover = low;
  			index = sctp_phashfn(rover);
  			head = &sctp_port_hashtable[index];
  			sctp_spin_lock(&head->lock);
  			sctp_for_each_hentry(pp, node, &head->chain)
  				if (pp->port == rover)
  					goto next;
  			break;
  		next:
  			sctp_spin_unlock(&head->lock);
  		} while (--remaining > 0);
  
  		/* Exhausted local port range during search? */
  		ret = 1;
  		if (remaining <= 0)
  			goto fail;
  
  		/* OK, here is the one we will use.  HEAD (the port
  		 * hash table list entry) is non-NULL and we hold it's
  		 * mutex.
  		 */
  		snum = rover;
  	} else {
  		/* We are given an specific port number; we verify
  		 * that it is not being used. If it is used, we will
  		 * exahust the search in the hash list corresponding
  		 * to the port number (snum) - we detect that with the
  		 * port iterator, pp being NULL.
  		 */
  		head = &sctp_port_hashtable[sctp_phashfn(snum)];
  		sctp_spin_lock(&head->lock);
  		sctp_for_each_hentry(pp, node, &head->chain) {
  			if (pp->port == snum)
  				goto pp_found;
  		}
  	}
  	pp = NULL;
  	goto pp_not_found;
  pp_found:
  	if (!hlist_empty(&pp->owner)) {
  		/* We had a port hash table hit - there is an
  		 * available port (pp != NULL) and it is being
  		 * used by other socket (pp->owner not empty); that other
  		 * socket is going to be sk2.
  		 */
  		int reuse = sk->sk_reuse;
  		struct sock *sk2;
  		struct hlist_node *node;
  
  		SCTP_DEBUG_PRINTK("sctp_get_port() found a possible match\n");
  		if (pp->fastreuse && sk->sk_reuse &&
  			sk->sk_state != SCTP_SS_LISTENING)
  			goto success;
  
  		/* Run through the list of sockets bound to the port
  		 * (pp->port) [via the pointers bind_next and
  		 * bind_pprev in the struct sock *sk2 (pp->sk)]. On each one,
  		 * we get the endpoint they describe and run through
  		 * the endpoint's list of IP (v4 or v6) addresses,
  		 * comparing each of the addresses with the address of
  		 * the socket sk. If we find a match, then that means
  		 * that this port/socket (sk) combination are already
  		 * in an endpoint.
  		 */
  		sk_for_each_bound(sk2, node, &pp->owner) {
  			struct sctp_endpoint *ep2;
  			ep2 = sctp_sk(sk2)->ep;
  
  			if (sk == sk2 ||
  			    (reuse && sk2->sk_reuse &&
  			     sk2->sk_state != SCTP_SS_LISTENING))
  				continue;
  
  			if (sctp_bind_addr_conflict(&ep2->base.bind_addr, addr,
  						 sctp_sk(sk2), sctp_sk(sk))) {
  				ret = (long)sk2;
  				goto fail_unlock;
  			}
  		}
  		SCTP_DEBUG_PRINTK("sctp_get_port(): Found a match\n");
  	}
  pp_not_found:
  	/* If there was a hash table miss, create a new port.  */
  	ret = 1;
  	if (!pp && !(pp = sctp_bucket_create(head, snum)))
  		goto fail_unlock;
  
  	/* In either case (hit or miss), make sure fastreuse is 1 only
  	 * if sk->sk_reuse is too (that is, if the caller requested
  	 * SO_REUSEADDR on this socket -sk-).
  	 */
  	if (hlist_empty(&pp->owner)) {
  		if (sk->sk_reuse && sk->sk_state != SCTP_SS_LISTENING)
  			pp->fastreuse = 1;
  		else
  			pp->fastreuse = 0;
  	} else if (pp->fastreuse &&
  		(!sk->sk_reuse || sk->sk_state == SCTP_SS_LISTENING))
  		pp->fastreuse = 0;
  
  	/* We are set, so fill up all the data in the hash table
  	 * entry, tie the socket list information with the rest of the
  	 * sockets FIXME: Blurry, NPI (ipg).
  	 */
  success:
  	if (!sctp_sk(sk)->bind_hash) {
  		inet_sk(sk)->inet_num = snum;
  		sk_add_bind_node(sk, &pp->owner);
  		sctp_sk(sk)->bind_hash = pp;
  	}
  	ret = 0;
  
  fail_unlock:
  	sctp_spin_unlock(&head->lock);
  
  fail:
  	sctp_local_bh_enable();
  	return ret;
  }
  
  /* Assign a 'snum' port to the socket.  If snum == 0, an ephemeral
   * port is requested.
   */
  static int sctp_get_port(struct sock *sk, unsigned short snum)
  {
  	long ret;
  	union sctp_addr addr;
  	struct sctp_af *af = sctp_sk(sk)->pf->af;
  
  	/* Set up a dummy address struct from the sk. */
  	af->from_sk(&addr, sk);
  	addr.v4.sin_port = htons(snum);
  
  	/* Note: sk->sk_num gets filled in if ephemeral port request. */
  	ret = sctp_get_port_local(sk, &addr);
  
  	return (ret ? 1 : 0);
  }
  
  /*
   *  Move a socket to LISTENING state.
   */
  SCTP_STATIC int sctp_listen_start(struct sock *sk, int backlog)
  {
  	struct sctp_sock *sp = sctp_sk(sk);
  	struct sctp_endpoint *ep = sp->ep;
  	struct crypto_hash *tfm = NULL;
  
  	/* Allocate HMAC for generating cookie. */
  	if (!sctp_sk(sk)->hmac && sctp_hmac_alg) {
  		tfm = crypto_alloc_hash(sctp_hmac_alg, 0, CRYPTO_ALG_ASYNC);
  		if (IS_ERR(tfm)) {
  			if (net_ratelimit()) {
  				printk(KERN_INFO
  				       "SCTP: failed to load transform for %s: %ld\n",
  					sctp_hmac_alg, PTR_ERR(tfm));
  			}
  			return -ENOSYS;
  		}
  		sctp_sk(sk)->hmac = tfm;
  	}
  
  	/*
  	 * If a bind() or sctp_bindx() is not called prior to a listen()
  	 * call that allows new associations to be accepted, the system
  	 * picks an ephemeral port and will choose an address set equivalent
  	 * to binding with a wildcard address.
  	 *
  	 * This is not currently spelled out in the SCTP sockets
  	 * extensions draft, but follows the practice as seen in TCP
  	 * sockets.
  	 *
  	 */
  	sk->sk_state = SCTP_SS_LISTENING;
  	if (!ep->base.bind_addr.port) {
  		if (sctp_autobind(sk))
  			return -EAGAIN;
  	} else {
  		if (sctp_get_port(sk, inet_sk(sk)->inet_num)) {
  			sk->sk_state = SCTP_SS_CLOSED;
  			return -EADDRINUSE;
  		}
  	}
  
  	sk->sk_max_ack_backlog = backlog;
  	sctp_hash_endpoint(ep);
  	return 0;
  }
  
  /*
   * 4.1.3 / 5.1.3 listen()
   *
   *   By default, new associations are not accepted for UDP style sockets.
   *   An application uses listen() to mark a socket as being able to
   *   accept new associations.
   *
   *   On TCP style sockets, applications use listen() to ready the SCTP
   *   endpoint for accepting inbound associations.
   *
   *   On both types of endpoints a backlog of '0' disables listening.
   *
   *  Move a socket to LISTENING state.
   */
  int sctp_inet_listen(struct socket *sock, int backlog)
  {
  	struct sock *sk = sock->sk;
  	struct sctp_endpoint *ep = sctp_sk(sk)->ep;
  	int err = -EINVAL;
  
  	if (unlikely(backlog < 0))
  		return err;
  
  	sctp_lock_sock(sk);
  
  	/* Peeled-off sockets are not allowed to listen().  */
  	if (sctp_style(sk, UDP_HIGH_BANDWIDTH))
  		goto out;
  
  	if (sock->state != SS_UNCONNECTED)
  		goto out;
  
  	/* If backlog is zero, disable listening. */
  	if (!backlog) {
  		if (sctp_sstate(sk, CLOSED))
  			goto out;
  
  		err = 0;
  		sctp_unhash_endpoint(ep);
  		sk->sk_state = SCTP_SS_CLOSED;
  		if (sk->sk_reuse)
  			sctp_sk(sk)->bind_hash->fastreuse = 1;
  		goto out;
  	}
  
  	/* If we are already listening, just update the backlog */
  	if (sctp_sstate(sk, LISTENING))
  		sk->sk_max_ack_backlog = backlog;
  	else {
  		err = sctp_listen_start(sk, backlog);
  		if (err)
  			goto out;
  	}
  
  	err = 0;
  out:
  	sctp_release_sock(sk);
  	return err;
  }
  
  /*
   * This function is done by modeling the current datagram_poll() and the
   * tcp_poll().  Note that, based on these implementations, we don't
   * lock the socket in this function, even though it seems that,
   * ideally, locking or some other mechanisms can be used to ensure
   * the integrity of the counters (sndbuf and wmem_alloc) used
   * in this place.  We assume that we don't need locks either until proven
   * otherwise.
   *
   * Another thing to note is that we include the Async I/O support
   * here, again, by modeling the current TCP/UDP code.  We don't have
   * a good way to test with it yet.
   */
  unsigned int sctp_poll(struct file *file, struct socket *sock, poll_table *wait)
  {
  	struct sock *sk = sock->sk;
  	struct sctp_sock *sp = sctp_sk(sk);
  	unsigned int mask;
  
  	poll_wait(file, sk->sk_sleep, wait);
  
  	/* A TCP-style listening socket becomes readable when the accept queue
  	 * is not empty.
  	 */
  	if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
  		return (!list_empty(&sp->ep->asocs)) ?
  			(POLLIN | POLLRDNORM) : 0;
  
  	mask = 0;
  
  	/* Is there any exceptional events?  */
  	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
  		mask |= POLLERR;
  	if (sk->sk_shutdown & RCV_SHUTDOWN)
  		mask |= POLLRDHUP;
  	if (sk->sk_shutdown == SHUTDOWN_MASK)
  		mask |= POLLHUP;
  
  	/* Is it readable?  Reconsider this code with TCP-style support.  */
  	if (!skb_queue_empty(&sk->sk_receive_queue) ||
  	    (sk->sk_shutdown & RCV_SHUTDOWN))
  		mask |= POLLIN | POLLRDNORM;
  
  	/* The association is either gone or not ready.  */
  	if (!sctp_style(sk, UDP) && sctp_sstate(sk, CLOSED))
  		return mask;
  
  	/* Is it writable?  */
  	if (sctp_writeable(sk)) {
  		mask |= POLLOUT | POLLWRNORM;
  	} else {
  		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
  		/*
  		 * Since the socket is not locked, the buffer
  		 * might be made available after the writeable check and
  		 * before the bit is set.  This could cause a lost I/O
  		 * signal.  tcp_poll() has a race breaker for this race
  		 * condition.  Based on their implementation, we put
  		 * in the following code to cover it as well.
  		 */
  		if (sctp_writeable(sk))
  			mask |= POLLOUT | POLLWRNORM;
  	}
  	return mask;
  }
  
  /********************************************************************
   * 2nd Level Abstractions
   ********************************************************************/
  
  static struct sctp_bind_bucket *sctp_bucket_create(
  	struct sctp_bind_hashbucket *head, unsigned short snum)
  {
  	struct sctp_bind_bucket *pp;
  
  	pp = kmem_cache_alloc(sctp_bucket_cachep, GFP_ATOMIC);
  	if (pp) {
  		SCTP_DBG_OBJCNT_INC(bind_bucket);
  		pp->port = snum;
  		pp->fastreuse = 0;
  		INIT_HLIST_HEAD(&pp->owner);
  		hlist_add_head(&pp->node, &head->chain);
  	}
  	return pp;
  }
  
  /* Caller must hold hashbucket lock for this tb with local BH disabled */
  static void sctp_bucket_destroy(struct sctp_bind_bucket *pp)
  {
  	if (pp && hlist_empty(&pp->owner)) {
  		__hlist_del(&pp->node);
  		kmem_cache_free(sctp_bucket_cachep, pp);
  		SCTP_DBG_OBJCNT_DEC(bind_bucket);
  	}
  }
  
  /* Release this socket's reference to a local port.  */
  static inline void __sctp_put_port(struct sock *sk)
  {
  	struct sctp_bind_hashbucket *head =
  		&sctp_port_hashtable[sctp_phashfn(inet_sk(sk)->inet_num)];
  	struct sctp_bind_bucket *pp;
  
  	sctp_spin_lock(&head->lock);
  	pp = sctp_sk(sk)->bind_hash;
  	__sk_del_bind_node(sk);
  	sctp_sk(sk)->bind_hash = NULL;
  	inet_sk(sk)->inet_num = 0;
  	sctp_bucket_destroy(pp);
  	sctp_spin_unlock(&head->lock);
  }
  
  void sctp_put_port(struct sock *sk)
  {
  	sctp_local_bh_disable();
  	__sctp_put_port(sk);
  	sctp_local_bh_enable();
  }
  
  /*
   * The system picks an ephemeral port and choose an address set equivalent
   * to binding with a wildcard address.
   * One of those addresses will be the primary address for the association.
   * This automatically enables the multihoming capability of SCTP.
   */
  static int sctp_autobind(struct sock *sk)
  {
  	union sctp_addr autoaddr;
  	struct sctp_af *af;
  	__be16 port;
  
  	/* Initialize a local sockaddr structure to INADDR_ANY. */
  	af = sctp_sk(sk)->pf->af;
  
  	port = htons(inet_sk(sk)->inet_num);
  	af->inaddr_any(&autoaddr, port);
  
  	return sctp_do_bind(sk, &autoaddr, af->sockaddr_len);
  }
  
  /* Parse out IPPROTO_SCTP CMSG headers.  Perform only minimal validation.
   *
   * From RFC 2292
   * 4.2 The cmsghdr Structure *
   *
   * When ancillary data is sent or received, any number of ancillary data
   * objects can be specified by the msg_control and msg_controllen members of
   * the msghdr structure, because each object is preceded by
   * a cmsghdr structure defining the object's length (the cmsg_len member).
   * Historically Berkeley-derived implementations have passed only one object
   * at a time, but this API allows multiple objects to be
   * passed in a single call to sendmsg() or recvmsg(). The following example
   * shows two ancillary data objects in a control buffer.
   *
   *   |<--------------------------- msg_controllen -------------------------->|
   *   |                                                                       |
   *
   *   |<----- ancillary data object ----->|<----- ancillary data object ----->|
   *
   *   |<---------- CMSG_SPACE() --------->|<---------- CMSG_SPACE() --------->|
   *   |                                   |                                   |
   *
   *   |<---------- cmsg_len ---------->|  |<--------- cmsg_len ----------->|  |
   *
   *   |<--------- CMSG_LEN() --------->|  |<-------- CMSG_LEN() ---------->|  |
   *   |                                |  |                                |  |
   *
   *   +-----+-----+-----+--+-----------+--+-----+-----+-----+--+-----------+--+
   *   |cmsg_|cmsg_|cmsg_|XX|           |XX|cmsg_|cmsg_|cmsg_|XX|           |XX|
   *
   *   |len  |level|type |XX|cmsg_data[]|XX|len  |level|type |XX|cmsg_data[]|XX|
   *
   *   +-----+-----+-----+--+-----------+--+-----+-----+-----+--+-----------+--+
   *    ^
   *    |
   *
   * msg_control
   * points here
   */
  SCTP_STATIC int sctp_msghdr_parse(const struct msghdr *msg,
  				  sctp_cmsgs_t *cmsgs)
  {
  	struct cmsghdr *cmsg;
  	struct msghdr *my_msg = (struct msghdr *)msg;
  
  	for (cmsg = CMSG_FIRSTHDR(msg);
  	     cmsg != NULL;
  	     cmsg = CMSG_NXTHDR(my_msg, cmsg)) {
  		if (!CMSG_OK(my_msg, cmsg))
  			return -EINVAL;
  
  		/* Should we parse this header or ignore?  */
  		if (cmsg->cmsg_level != IPPROTO_SCTP)
  			continue;
  
  		/* Strictly check lengths following example in SCM code.  */
  		switch (cmsg->cmsg_type) {
  		case SCTP_INIT:
  			/* SCTP Socket API Extension
  			 * 5.2.1 SCTP Initiation Structure (SCTP_INIT)
  			 *
  			 * This cmsghdr structure provides information for
  			 * initializing new SCTP associations with sendmsg().
  			 * The SCTP_INITMSG socket option uses this same data
  			 * structure.  This structure is not used for
  			 * recvmsg().
  			 *
  			 * cmsg_level    cmsg_type      cmsg_data[]
  			 * ------------  ------------   ----------------------
  			 * IPPROTO_SCTP  SCTP_INIT      struct sctp_initmsg
  			 */
  			if (cmsg->cmsg_len !=
  			    CMSG_LEN(sizeof(struct sctp_initmsg)))
  				return -EINVAL;
  			cmsgs->init = (struct sctp_initmsg *)CMSG_DATA(cmsg);
  			break;
  
  		case SCTP_SNDRCV:
  			/* SCTP Socket API Extension
  			 * 5.2.2 SCTP Header Information Structure(SCTP_SNDRCV)
  			 *
  			 * This cmsghdr structure specifies SCTP options for
  			 * sendmsg() and describes SCTP header information
  			 * about a received message through recvmsg().
  			 *
  			 * cmsg_level    cmsg_type      cmsg_data[]
  			 * ------------  ------------   ----------------------
  			 * IPPROTO_SCTP  SCTP_SNDRCV    struct sctp_sndrcvinfo
  			 */
  			if (cmsg->cmsg_len !=
  			    CMSG_LEN(sizeof(struct sctp_sndrcvinfo)))
  				return -EINVAL;
  
  			cmsgs->info =
  				(struct sctp_sndrcvinfo *)CMSG_DATA(cmsg);
  
  			/* Minimally, validate the sinfo_flags. */
  			if (cmsgs->info->sinfo_flags &
  			    ~(SCTP_UNORDERED | SCTP_ADDR_OVER |
  			      SCTP_ABORT | SCTP_EOF))
  				return -EINVAL;
  			break;
  
  		default:
  			return -EINVAL;
  		}
  	}
  	return 0;
  }
  
  /*
   * Wait for a packet..
   * Note: This function is the same function as in core/datagram.c
   * with a few modifications to make lksctp work.
   */
  static int sctp_wait_for_packet(struct sock * sk, int *err, long *timeo_p)
  {
  	int error;
  	DEFINE_WAIT(wait);
  
  	prepare_to_wait_exclusive(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
  
  	/* Socket errors? */
  	error = sock_error(sk);
  	if (error)
  		goto out;
  
  	if (!skb_queue_empty(&sk->sk_receive_queue))
  		goto ready;
  
  	/* Socket shut down?  */
  	if (sk->sk_shutdown & RCV_SHUTDOWN)
  		goto out;
  
  	/* Sequenced packets can come disconnected.  If so we report the
  	 * problem.
  	 */
  	error = -ENOTCONN;
  
  	/* Is there a good reason to think that we may receive some data?  */
  	if (list_empty(&sctp_sk(sk)->ep->asocs) && !sctp_sstate(sk, LISTENING))
  		goto out;
  
  	/* Handle signals.  */
  	if (signal_pending(current))
  		goto interrupted;
  
  	/* Let another process have a go.  Since we are going to sleep
  	 * anyway.  Note: This may cause odd behaviors if the message
  	 * does not fit in the user's buffer, but this seems to be the
  	 * only way to honor MSG_DONTWAIT realistically.
  	 */
  	sctp_release_sock(sk);
  	*timeo_p = schedule_timeout(*timeo_p);
  	sctp_lock_sock(sk);
  
  ready:
  	finish_wait(sk->sk_sleep, &wait);
  	return 0;
  
  interrupted:
  	error = sock_intr_errno(*timeo_p);
  
  out:
  	finish_wait(sk->sk_sleep, &wait);
  	*err = error;
  	return error;
  }
  
  /* Receive a datagram.
   * Note: This is pretty much the same routine as in core/datagram.c
   * with a few changes to make lksctp work.
   */
  static struct sk_buff *sctp_skb_recv_datagram(struct sock *sk, int flags,
  					      int noblock, int *err)
  {
  	int error;
  	struct sk_buff *skb;
  	long timeo;
  
  	timeo = sock_rcvtimeo(sk, noblock);
  
  	SCTP_DEBUG_PRINTK("Timeout: timeo: %ld, MAX: %ld.\n",
  			  timeo, MAX_SCHEDULE_TIMEOUT);
  
  	do {
  		/* Again only user level code calls this function,
  		 * so nothing interrupt level
  		 * will suddenly eat the receive_queue.
  		 *
  		 *  Look at current nfs client by the way...
  		 *  However, this function was corrent in any case. 8)
  		 */
  		if (flags & MSG_PEEK) {
  			spin_lock_bh(&sk->sk_receive_queue.lock);
  			skb = skb_peek(&sk->sk_receive_queue);
  			if (skb)
  				atomic_inc(&skb->users);
  			spin_unlock_bh(&sk->sk_receive_queue.lock);
  		} else {
  			skb = skb_dequeue(&sk->sk_receive_queue);
  		}
  
  		if (skb)
  			return skb;
  
  		/* Caller is allowed not to check sk->sk_err before calling. */
  		error = sock_error(sk);
  		if (error)
  			goto no_packet;
  
  		if (sk->sk_shutdown & RCV_SHUTDOWN)
  			break;
  
  		/* User doesn't want to wait.  */
  		error = -EAGAIN;
  		if (!timeo)
  			goto no_packet;
  	} while (sctp_wait_for_packet(sk, err, &timeo) == 0);
  
  	return NULL;
  
  no_packet:
  	*err = error;
  	return NULL;
  }
  
  /* If sndbuf has changed, wake up per association sndbuf waiters.  */
  static void __sctp_write_space(struct sctp_association *asoc)
  {
  	struct sock *sk = asoc->base.sk;
  	struct socket *sock = sk->sk_socket;
  
  	if ((sctp_wspace(asoc) > 0) && sock) {
  		if (waitqueue_active(&asoc->wait))
  			wake_up_interruptible(&asoc->wait);
  
  		if (sctp_writeable(sk)) {
  			if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
  				wake_up_interruptible(sk->sk_sleep);
  
  			/* Note that we try to include the Async I/O support
  			 * here by modeling from the current TCP/UDP code.
  			 * We have not tested with it yet.
  			 */
  			if (sock->fasync_list &&
  			    !(sk->sk_shutdown & SEND_SHUTDOWN))
  				sock_wake_async(sock,
  						SOCK_WAKE_SPACE, POLL_OUT);
  		}
  	}
  }
  
  /* Do accounting for the sndbuf space.
   * Decrement the used sndbuf space of the corresponding association by the
   * data size which was just transmitted(freed).
   */
  static void sctp_wfree(struct sk_buff *skb)
  {
  	struct sctp_association *asoc;
  	struct sctp_chunk *chunk;
  	struct sock *sk;
  
  	/* Get the saved chunk pointer.  */
  	chunk = *((struct sctp_chunk **)(skb->cb));
  	asoc = chunk->asoc;
  	sk = asoc->base.sk;
  	asoc->sndbuf_used -= SCTP_DATA_SNDSIZE(chunk) +
  				sizeof(struct sk_buff) +
  				sizeof(struct sctp_chunk);
  
  	atomic_sub(sizeof(struct sctp_chunk), &sk->sk_wmem_alloc);
  
  	/*
  	 * This undoes what is done via sctp_set_owner_w and sk_mem_charge
  	 */
  	sk->sk_wmem_queued   -= skb->truesize;
  	sk_mem_uncharge(sk, skb->truesize);
  
  	sock_wfree(skb);
  	__sctp_write_space(asoc);
  
  	sctp_association_put(asoc);
  }
  
  /* Do accounting for the receive space on the socket.
   * Accounting for the association is done in ulpevent.c
   * We set this as a destructor for the cloned data skbs so that
   * accounting is done at the correct time.
   */
  void sctp_sock_rfree(struct sk_buff *skb)
  {
  	struct sock *sk = skb->sk;
  	struct sctp_ulpevent *event = sctp_skb2event(skb);
  
  	atomic_sub(event->rmem_len, &sk->sk_rmem_alloc);
  
  	/*
  	 * Mimic the behavior of sock_rfree
  	 */
  	sk_mem_uncharge(sk, event->rmem_len);
  }
  
  
  /* Helper function to wait for space in the sndbuf.  */
  static int sctp_wait_for_sndbuf(struct sctp_association *asoc, long *timeo_p,
  				size_t msg_len)
  {
  	struct sock *sk = asoc->base.sk;
  	int err = 0;
  	long current_timeo = *timeo_p;
  	DEFINE_WAIT(wait);
  
  	SCTP_DEBUG_PRINTK("wait_for_sndbuf: asoc=%p, timeo=%ld, msg_len=%zu\n",
  			  asoc, (long)(*timeo_p), msg_len);
  
  	/* Increment the association's refcnt.  */
  	sctp_association_hold(asoc);
  
  	/* Wait on the association specific sndbuf space. */
  	for (;;) {
  		prepare_to_wait_exclusive(&asoc->wait, &wait,
  					  TASK_INTERRUPTIBLE);
  		if (!*timeo_p)
  			goto do_nonblock;
  		if (sk->sk_err || asoc->state >= SCTP_STATE_SHUTDOWN_PENDING ||
  		    asoc->base.dead)
  			goto do_error;
  		if (signal_pending(current))
  			goto do_interrupted;
  		if (msg_len <= sctp_wspace(asoc))
  			break;
  
  		/* Let another process have a go.  Since we are going
  		 * to sleep anyway.
  		 */
  		sctp_release_sock(sk);
  		current_timeo = schedule_timeout(current_timeo);
  		BUG_ON(sk != asoc->base.sk);
  		sctp_lock_sock(sk);
  
  		*timeo_p = current_timeo;
  	}
  
  out:
  	finish_wait(&asoc->wait, &wait);
  
  	/* Release the association's refcnt.  */
  	sctp_association_put(asoc);
  
  	return err;
  
  do_error:
  	err = -EPIPE;
  	goto out;
  
  do_interrupted:
  	err = sock_intr_errno(*timeo_p);
  	goto out;
  
  do_nonblock:
  	err = -EAGAIN;
  	goto out;
  }
  
  void sctp_data_ready(struct sock *sk, int len)
  {
  	read_lock_bh(&sk->sk_callback_lock);
  	if (sk_has_sleeper(sk))
  		wake_up_interruptible_sync_poll(sk->sk_sleep, POLLIN |
  						POLLRDNORM | POLLRDBAND);
  	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
  	read_unlock_bh(&sk->sk_callback_lock);
  }
  
  /* If socket sndbuf has changed, wake up all per association waiters.  */
  void sctp_write_space(struct sock *sk)
  {
  	struct sctp_association *asoc;
  
  	/* Wake up the tasks in each wait queue.  */
  	list_for_each_entry(asoc, &((sctp_sk(sk))->ep->asocs), asocs) {
  		__sctp_write_space(asoc);
  	}
  }
  
  /* Is there any sndbuf space available on the socket?
   *
   * Note that sk_wmem_alloc is the sum of the send buffers on all of the
   * associations on the same socket.  For a UDP-style socket with
   * multiple associations, it is possible for it to be "unwriteable"
   * prematurely.  I assume that this is acceptable because
   * a premature "unwriteable" is better than an accidental "writeable" which
   * would cause an unwanted block under certain circumstances.  For the 1-1
   * UDP-style sockets or TCP-style sockets, this code should work.
   *  - Daisy
   */
  static int sctp_writeable(struct sock *sk)
  {
  	int amt = 0;
  
  	amt = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
  	if (amt < 0)
  		amt = 0;
  	return amt;
  }
  
  /* Wait for an association to go into ESTABLISHED state. If timeout is 0,
   * returns immediately with EINPROGRESS.
   */
  static int sctp_wait_for_connect(struct sctp_association *asoc, long *timeo_p)
  {
  	struct sock *sk = asoc->base.sk;
  	int err = 0;
  	long current_timeo = *timeo_p;
  	DEFINE_WAIT(wait);
  
  	SCTP_DEBUG_PRINTK("%s: asoc=%p, timeo=%ld\n", __func__, asoc,
  			  (long)(*timeo_p));
  
  	/* Increment the association's refcnt.  */
  	sctp_association_hold(asoc);
  
  	for (;;) {
  		prepare_to_wait_exclusive(&asoc->wait, &wait,
  					  TASK_INTERRUPTIBLE);
  		if (!*timeo_p)
  			goto do_nonblock;
  		if (sk->sk_shutdown & RCV_SHUTDOWN)
  			break;
  		if (sk->sk_err || asoc->state >= SCTP_STATE_SHUTDOWN_PENDING ||
  		    asoc->base.dead)
  			goto do_error;
  		if (signal_pending(current))
  			goto do_interrupted;
  
  		if (sctp_state(asoc, ESTABLISHED))
  			break;
  
  		/* Let another process have a go.  Since we are going
  		 * to sleep anyway.
  		 */
  		sctp_release_sock(sk);
  		current_timeo = schedule_timeout(current_timeo);
  		sctp_lock_sock(sk);
  
  		*timeo_p = current_timeo;
  	}
  
  out:
  	finish_wait(&asoc->wait, &wait);
  
  	/* Release the association's refcnt.  */
  	sctp_association_put(asoc);
  
  	return err;
  
  do_error:
  	if (asoc->init_err_counter + 1 > asoc->max_init_attempts)
  		err = -ETIMEDOUT;
  	else
  		err = -ECONNREFUSED;
  	goto out;
  
  do_interrupted:
  	err = sock_intr_errno(*timeo_p);
  	goto out;
  
  do_nonblock:
  	err = -EINPROGRESS;
  	goto out;
  }
  
  static int sctp_wait_for_accept(struct sock *sk, long timeo)
  {
  	struct sctp_endpoint *ep;
  	int err = 0;
  	DEFINE_WAIT(wait);
  
  	ep = sctp_sk(sk)->ep;
  
  
  	for (;;) {
  		prepare_to_wait_exclusive(sk->sk_sleep, &wait,
  					  TASK_INTERRUPTIBLE);
  
  		if (list_empty(&ep->asocs)) {
  			sctp_release_sock(sk);
  			timeo = schedule_timeout(timeo);
  			sctp_lock_sock(sk);
  		}
  
  		err = -EINVAL;
  		if (!sctp_sstate(sk, LISTENING))
  			break;
  
  		err = 0;
  		if (!list_empty(&ep->asocs))
  			break;
  
  		err = sock_intr_errno(timeo);
  		if (signal_pending(current))
  			break;
  
  		err = -EAGAIN;
  		if (!timeo)
  			break;
  	}
  
  	finish_wait(sk->sk_sleep, &wait);
  
  	return err;
  }
  
  static void sctp_wait_for_close(struct sock *sk, long timeout)
  {
  	DEFINE_WAIT(wait);
  
  	do {
  		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
  		if (list_empty(&sctp_sk(sk)->ep->asocs))
  			break;
  		sctp_release_sock(sk);
  		timeout = schedule_timeout(timeout);
  		sctp_lock_sock(sk);
  	} while (!signal_pending(current) && timeout);
  
  	finish_wait(sk->sk_sleep, &wait);
  }
  
  static void sctp_skb_set_owner_r_frag(struct sk_buff *skb, struct sock *sk)
  {
  	struct sk_buff *frag;
  
  	if (!skb->data_len)
  		goto done;
  
  	/* Don't forget the fragments. */
  	skb_walk_frags(skb, frag)
  		sctp_skb_set_owner_r_frag(frag, sk);
  
  done:
  	sctp_skb_set_owner_r(skb, sk);
  }
  
  void sctp_copy_sock(struct sock *newsk, struct sock *sk,
  		    struct sctp_association *asoc)
  {
  	struct inet_sock *inet = inet_sk(sk);
  	struct inet_sock *newinet;
  
  	newsk->sk_type = sk->sk_type;
  	newsk->sk_bound_dev_if = sk->sk_bound_dev_if;
  	newsk->sk_flags = sk->sk_flags;
  	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 = sk->sk_family;
  	newsk->sk_protocol = IPPROTO_SCTP;
  	newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
  	newsk->sk_sndbuf = sk->sk_sndbuf;
  	newsk->sk_rcvbuf = sk->sk_rcvbuf;
  	newsk->sk_lingertime = sk->sk_lingertime;
  	newsk->sk_rcvtimeo = sk->sk_rcvtimeo;
  	newsk->sk_sndtimeo = sk->sk_sndtimeo;
  
  	newinet = inet_sk(newsk);
  
  	/* Initialize sk's sport, dport, rcv_saddr and daddr for
  	 * getsockname() and getpeername()
  	 */
  	newinet->inet_sport = inet->inet_sport;
  	newinet->inet_saddr = inet->inet_saddr;
  	newinet->inet_rcv_saddr = inet->inet_rcv_saddr;
  	newinet->inet_dport = htons(asoc->peer.port);
  	newinet->pmtudisc = inet->pmtudisc;
  	newinet->inet_id = asoc->next_tsn ^ jiffies;
  
  	newinet->uc_ttl = inet->uc_ttl;
  	newinet->mc_loop = 1;
  	newinet->mc_ttl = 1;
  	newinet->mc_index = 0;
  	newinet->mc_list = NULL;
  }
  
  /* Populate the fields of the newsk from the oldsk and migrate the assoc
   * and its messages to the newsk.
   */
  static void sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
  			      struct sctp_association *assoc,
  			      sctp_socket_type_t type)
  {
  	struct sctp_sock *oldsp = sctp_sk(oldsk);
  	struct sctp_sock *newsp = sctp_sk(newsk);
  	struct sctp_bind_bucket *pp; /* hash list port iterator */
  	struct sctp_endpoint *newep = newsp->ep;
  	struct sk_buff *skb, *tmp;
  	struct sctp_ulpevent *event;
  	struct sctp_bind_hashbucket *head;
  
  	/* Migrate socket buffer sizes and all the socket level options to the
  	 * new socket.
  	 */
  	newsk->sk_sndbuf = oldsk->sk_sndbuf;
  	newsk->sk_rcvbuf = oldsk->sk_rcvbuf;
  	/* Brute force copy old sctp opt. */
  	inet_sk_copy_descendant(newsk, oldsk);
  
  	/* Restore the ep value that was overwritten with the above structure
  	 * copy.
  	 */
  	newsp->ep = newep;
  	newsp->hmac = NULL;
  
  	/* Hook this new socket in to the bind_hash list. */
  	head = &sctp_port_hashtable[sctp_phashfn(inet_sk(oldsk)->inet_num)];
  	sctp_local_bh_disable();
  	sctp_spin_lock(&head->lock);
  	pp = sctp_sk(oldsk)->bind_hash;
  	sk_add_bind_node(newsk, &pp->owner);
  	sctp_sk(newsk)->bind_hash = pp;
  	inet_sk(newsk)->inet_num = inet_sk(oldsk)->inet_num;
  	sctp_spin_unlock(&head->lock);
  	sctp_local_bh_enable();
  
  	/* Copy the bind_addr list from the original endpoint to the new
  	 * endpoint so that we can handle restarts properly
  	 */
  	sctp_bind_addr_dup(&newsp->ep->base.bind_addr,
  				&oldsp->ep->base.bind_addr, GFP_KERNEL);
  
  	/* Move any messages in the old socket's receive queue that are for the
  	 * peeled off association to the new socket's receive queue.
  	 */
  	sctp_skb_for_each(skb, &oldsk->sk_receive_queue, tmp) {
  		event = sctp_skb2event(skb);
  		if (event->asoc == assoc) {
  			__skb_unlink(skb, &oldsk->sk_receive_queue);
  			__skb_queue_tail(&newsk->sk_receive_queue, skb);
  			sctp_skb_set_owner_r_frag(skb, newsk);
  		}
  	}
  
  	/* Clean up any messages pending delivery due to partial
  	 * delivery.   Three cases:
  	 * 1) No partial deliver;  no work.
  	 * 2) Peeling off partial delivery; keep pd_lobby in new pd_lobby.
  	 * 3) Peeling off non-partial delivery; move pd_lobby to receive_queue.
  	 */
  	skb_queue_head_init(&newsp->pd_lobby);
  	atomic_set(&sctp_sk(newsk)->pd_mode, assoc->ulpq.pd_mode);
  
  	if (atomic_read(&sctp_sk(oldsk)->pd_mode)) {
  		struct sk_buff_head *queue;
  
  		/* Decide which queue to move pd_lobby skbs to. */
  		if (assoc->ulpq.pd_mode) {
  			queue = &newsp->pd_lobby;
  		} else
  			queue = &newsk->sk_receive_queue;
  
  		/* Walk through the pd_lobby, looking for skbs that
  		 * need moved to the new socket.
  		 */
  		sctp_skb_for_each(skb, &oldsp->pd_lobby, tmp) {
  			event = sctp_skb2event(skb);
  			if (event->asoc == assoc) {
  				__skb_unlink(skb, &oldsp->pd_lobby);
  				__skb_queue_tail(queue, skb);
  				sctp_skb_set_owner_r_frag(skb, newsk);
  			}
  		}
  
  		/* Clear up any skbs waiting for the partial
  		 * delivery to finish.
  		 */
  		if (assoc->ulpq.pd_mode)
  			sctp_clear_pd(oldsk, NULL);
  
  	}
  
  	sctp_skb_for_each(skb, &assoc->ulpq.reasm, tmp)
  		sctp_skb_set_owner_r_frag(skb, newsk);
  
  	sctp_skb_for_each(skb, &assoc->ulpq.lobby, tmp)
  		sctp_skb_set_owner_r_frag(skb, newsk);
  
  	/* Set the type of socket to indicate that it is peeled off from the
  	 * original UDP-style socket or created with the accept() call on a
  	 * TCP-style socket..
  	 */
  	newsp->type = type;
  
  	/* Mark the new socket "in-use" by the user so that any packets
  	 * that may arrive on the association after we've moved it are
  	 * queued to the backlog.  This prevents a potential race between
  	 * backlog processing on the old socket and new-packet processing
  	 * on the new socket.
  	 *
  	 * The caller has just allocated newsk so we can guarantee that other
  	 * paths won't try to lock it and then oldsk.
  	 */
  	lock_sock_nested(newsk, SINGLE_DEPTH_NESTING);
  	sctp_assoc_migrate(assoc, newsk);
  
  	/* If the association on the newsk is already closed before accept()
  	 * is called, set RCV_SHUTDOWN flag.
  	 */
  	if (sctp_state(assoc, CLOSED) && sctp_style(newsk, TCP))
  		newsk->sk_shutdown |= RCV_SHUTDOWN;
  
  	newsk->sk_state = SCTP_SS_ESTABLISHED;
  	sctp_release_sock(newsk);
  }
  
  
  /* This proto struct describes the ULP interface for SCTP.  */
  struct proto sctp_prot = {
  	.name        =	"SCTP",
  	.owner       =	THIS_MODULE,
  	.close       =	sctp_close,
  	.connect     =	sctp_connect,
  	.disconnect  =	sctp_disconnect,
  	.accept      =	sctp_accept,
  	.ioctl       =	sctp_ioctl,
  	.init        =	sctp_init_sock,
  	.destroy     =	sctp_destroy_sock,
  	.shutdown    =	sctp_shutdown,
  	.setsockopt  =	sctp_setsockopt,
  	.getsockopt  =	sctp_getsockopt,
  	.sendmsg     =	sctp_sendmsg,
  	.recvmsg     =	sctp_recvmsg,
  	.bind        =	sctp_bind,
  	.backlog_rcv =	sctp_backlog_rcv,
  	.hash        =	sctp_hash,
  	.unhash      =	sctp_unhash,
  	.get_port    =	sctp_get_port,
  	.obj_size    =  sizeof(struct sctp_sock),
  	.sysctl_mem  =  sysctl_sctp_mem,
  	.sysctl_rmem =  sysctl_sctp_rmem,
  	.sysctl_wmem =  sysctl_sctp_wmem,
  	.memory_pressure = &sctp_memory_pressure,
  	.enter_memory_pressure = sctp_enter_memory_pressure,
  	.memory_allocated = &sctp_memory_allocated,
  	.sockets_allocated = &sctp_sockets_allocated,
  };
  
  #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  
  struct proto sctpv6_prot = {
  	.name		= "SCTPv6",
  	.owner		= THIS_MODULE,
  	.close		= sctp_close,
  	.connect	= sctp_connect,
  	.disconnect	= sctp_disconnect,
  	.accept		= sctp_accept,
  	.ioctl		= sctp_ioctl,
  	.init		= sctp_init_sock,
  	.destroy	= sctp_destroy_sock,
  	.shutdown	= sctp_shutdown,
  	.setsockopt	= sctp_setsockopt,
  	.getsockopt	= sctp_getsockopt,
  	.sendmsg	= sctp_sendmsg,
  	.recvmsg	= sctp_recvmsg,
  	.bind		= sctp_bind,
  	.backlog_rcv	= sctp_backlog_rcv,
  	.hash		= sctp_hash,
  	.unhash		= sctp_unhash,
  	.get_port	= sctp_get_port,
  	.obj_size	= sizeof(struct sctp6_sock),
  	.sysctl_mem	= sysctl_sctp_mem,
  	.sysctl_rmem	= sysctl_sctp_rmem,
  	.sysctl_wmem	= sysctl_sctp_wmem,
  	.memory_pressure = &sctp_memory_pressure,
  	.enter_memory_pressure = sctp_enter_memory_pressure,
  	.memory_allocated = &sctp_memory_allocated,
  	.sockets_allocated = &sctp_sockets_allocated,
  };
  #endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
  