socket.c

	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;

	/* 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->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);
	return 0;
}

/* Cleanup any SCTP per socket resources.  */
SCTP_STATIC int 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);

	return 0;
}

/* 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;
	}

	if (copy_from_user(&status, optval, sizeof(status))) {
		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;
	}

	if (copy_from_user(&pinfo, optval, sizeof(pinfo))) {
		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;
	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;
	if (copy_to_user(optval, &sctp_sk(sk)->autoclose, len))
		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 inet_sock *inetsk;
	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;

	/* 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);

	/* Make peeled-off sockets more like 1-1 accepted sockets.
	 * Set the daddr and initialize id to something more random
	 */
	inetsk = inet_sk(sock->sk);
	inetsk->daddr = asoc->peer.primary_addr.v4.sin_addr.s_addr;
	inetsk->id = asoc->next_tsn ^ jiffies;

	*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;
	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", __FUNCTION__, 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);
	if (retval < 0) {
		sock_release(newsock);
		goto out;
	}

	SCTP_DEBUG_PRINTK("%s: sk: %p asoc: %p newsk: %p sd: %d\n",
			  __FUNCTION__, sk, asoc, newsock->sk, retval);

	/* Return the fd mapped to the new socket.  */
	peeloff.sd = retval;
	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;

	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(( 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. Delayed Ack Timer (SCTP_DELAYED_ACK_TIME)
 *
 *   This options will get or set the delayed ack timer.  The time is set
 *   in milliseconds.  If the assoc_id is 0, then this sets or gets the
 *   endpoints default delayed ack timer value.  If the assoc_id field is
 *   non-zero, then the set or get effects the specified association.
 *
 *   struct sctp_assoc_value {
 *       sctp_assoc_t            assoc_id;
 *       uint32_t                assoc_value;
 *   };
 *
 *     assoc_id    - This parameter, indicates which association the
 *                   user is preforming 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 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.
 *
 *                   Note: a value of zero will leave the value alone,
 *                   but disable SACK delay. A non-zero value will also
 *                   enable SACK delay.
 */
static int sctp_getsockopt_delayed_ack_time(struct sock *sk, int len,
					    char __user *optval,
					    int __user *optlen)
{
	struct sctp_assoc_value  params;
	struct sctp_association *asoc = NULL;
	struct sctp_sock        *sp = sctp_sk(sk);

	if (len != sizeof(struct sctp_assoc_value))
		return - EINVAL;

	if (copy_from_user(&params, optval, len))
		return -EFAULT;

	/* 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.assoc_id);
	if (!asoc && params.assoc_id && sctp_style(sk, UDP))
		return -EINVAL;

	if (asoc) {
		/* Fetch association values. */
		if (asoc->param_flags & SPP_SACKDELAY_ENABLE)
			params.assoc_value = jiffies_to_msecs(
				asoc->sackdelay);
		else
			params.assoc_value = 0;
	} else {
		/* Fetch socket values. */
		if (sp->param_flags & SPP_SACKDELAY_ENABLE)
			params.assoc_value  = sp->sackdelay;
		else
			params.assoc_value  = 0;
	}

	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;
	if (copy_to_user(optval, &sctp_sk(sk)->initmsg, len))
		return -EFAULT;
	return 0;
}

static int sctp_getsockopt_peer_addrs_num_old(struct sock *sk, int len,
					      char __user *optval,
					      int __user *optlen)
{
	sctp_assoc_t id;
	struct sctp_association *asoc;
	struct list_head *pos;
	int cnt = 0;

	if (len != sizeof(sctp_assoc_t))
		return -EINVAL;

	if (copy_from_user(&id, optval, sizeof(sctp_assoc_t)))
		return -EFAULT;

	/* For UDP-style sockets, id specifies the association to query.  */
	asoc = sctp_id2assoc(sk, id);
	if (!asoc)
		return -EINVAL;

	list_for_each(pos, &asoc->peer.transport_addr_list) {
		cnt ++;
	}

	return cnt;
}

/*
 * Old API for getting list of peer addresses. Does not work for 32-bit
 * programs running on a 64-bit kernel
 */
static int sctp_getsockopt_peer_addrs_old(struct sock *sk, int len,
					  char __user *optval,
					  int __user *optlen)
{
	struct sctp_association *asoc;
	struct list_head *pos;
	int cnt = 0;
	struct sctp_getaddrs_old getaddrs;
	struct sctp_transport *from;
	void __user *to;
	union sctp_addr temp;
	struct sctp_sock *sp = sctp_sk(sk);
	int addrlen;

	if (len != sizeof(struct sctp_getaddrs_old))
		return -EINVAL;

	if (copy_from_user(&getaddrs, optval, sizeof(struct sctp_getaddrs_old)))
		return -EFAULT;

	if (getaddrs.addr_num <= 0) return -EINVAL;

	/* For UDP-style sockets, id specifies the association to query.  */
	asoc = sctp_id2assoc(sk, getaddrs.assoc_id);
	if (!asoc)
		return -EINVAL;

	to = (void __user *)getaddrs.addrs;
	list_for_each(pos, &asoc->peer.transport_addr_list) {
		from = list_entry(pos, struct sctp_transport, 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 (copy_to_user(to, &temp, addrlen))
			return -EFAULT;
		to += addrlen ;
		cnt ++;
		if (cnt >= getaddrs.addr_num) break;
	}
	getaddrs.addr_num = cnt;
	if (copy_to_user(optval, &getaddrs, sizeof(struct sctp_getaddrs_old)))
		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;
	struct list_head *pos;
	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 - sizeof(struct sctp_getaddrs) -
			offsetof(struct sctp_getaddrs,addrs);

	list_for_each(pos, &asoc->peer.transport_addr_list) {
		from = list_entry(pos, struct sctp_transport, 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_getsockopt_local_addrs_num_old(struct sock *sk, int len,
					       char __user *optval,
					       int __user *optlen)
{
	sctp_assoc_t id;
	struct sctp_bind_addr *bp;
	struct sctp_association *asoc;
	struct list_head *pos, *temp;
	struct sctp_sockaddr_entry *addr;
	rwlock_t *addr_lock;
	int cnt = 0;

	if (len != sizeof(sctp_assoc_t))
		return -EINVAL;

	if (copy_from_user(&id, optval, sizeof(sctp_assoc_t)))
		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 == id) {
		bp = &sctp_sk(sk)->ep->base.bind_addr;
		addr_lock = &sctp_sk(sk)->ep->base.addr_lock;
	} else {
		asoc = sctp_id2assoc(sk, id);
		if (!asoc)
			return -EINVAL;
		bp = &asoc->base.bind_addr;
		addr_lock = &asoc->base.addr_lock;
	}

	sctp_read_lock(addr_lock);

	/* If the endpoint is bound to 0.0.0.0 or ::0, count 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(&addr->a)) {
			list_for_each_safe(pos, temp, &sctp_local_addr_list) {
				addr = list_entry(pos,
						  struct sctp_sockaddr_entry,
						  list);
				if ((PF_INET == sk->sk_family) &&
				    (AF_INET6 == addr->a.sa.sa_family))
					continue;
				cnt++;
			}
		} else {
			cnt = 1;
		}
		goto done;
	}

	list_for_each(pos, &bp->address_list) {
		cnt ++;
	}

done:
	sctp_read_unlock(addr_lock);
	return cnt;
}

/* Helper function that copies local addresses to user and returns the number
 * of addresses copied.
 */
static int sctp_copy_laddrs_to_user_old(struct sock *sk, __u16 port, int max_addrs,
					void __user *to)
{
	struct list_head *pos, *next;
	struct sctp_sockaddr_entry *addr;
	union sctp_addr temp;
	int cnt = 0;
	int addrlen;

	list_for_each_safe(pos, next, &sctp_local_addr_list) {
		addr = list_entry(pos, struct sctp_sockaddr_entry, list);
		if ((PF_INET == sk->sk_family) &&
		    (AF_INET6 == addr->a.sa.sa_family))
			continue;
		memcpy(&temp, &addr->a, sizeof(temp));
		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 (copy_to_user(to, &temp, addrlen))