/*
   * net/tipc/bcast.c: TIPC broadcast code

   *

   * Copyright (c) 2004-2006, 2014-2017, Ericsson AB

   * Copyright (c) 2004, Intel Corporation.

   * Copyright (c) 2005, 2010-2011, Wind River Systems

   * All rights reserved.
   *

   * Redistribution and use in source and binary forms, with or without

   * modification, are permitted provided that the following conditions are met:
   *

   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. Neither the names of the copyright holders nor the names of its
   *    contributors may be used to endorse or promote products derived from
   *    this software without specific prior written permission.

   *

   * Alternatively, this software may be distributed under the terms of the
   * GNU General Public License ("GPL") version 2 as published by the Free
   * Software Foundation.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

   * POSSIBILITY OF SUCH DAMAGE.
   */

  #include <linux/tipc_config.h>

  #include "socket.h"
  #include "msg.h"

  #include "bcast.h"

  #include "link.h"

  #include "name_table.h"

  #define BCLINK_WIN_DEFAULT  50	/* bcast link window size (default) */
  #define BCLINK_WIN_MIN      32	/* bcast minimum link window size */

  const char tipc_bclink_name[] = "broadcast-link";

  /**

   * struct tipc_bc_base - base structure for keeping broadcast send state

   * @link: broadcast send link structure

   * @inputq: data input queue; will only carry SOCK_WAKEUP messages

   * @dests: array keeping number of reachable destinations per bearer

   * @primary_bearer: a bearer having links to all broadcast destinations, if any

   * @bcast_support: indicates if primary bearer, if any, supports broadcast

   * @force_bcast: forces broadcast for multicast traffic

   * @rcast_support: indicates if all peer nodes support replicast

   * @force_rcast: forces replicast for multicast traffic

   * @rc_ratio: dest count as percentage of cluster size where send method changes

   * @bc_threshold: calculated from rc_ratio; if dests > threshold use broadcast

   */
  struct tipc_bc_base {

  	struct tipc_link *link;

  	struct sk_buff_head inputq;

  	int dests[MAX_BEARERS];
  	int primary_bearer;

  	bool bcast_support;

  	bool force_bcast;

  	bool rcast_support;

  	bool force_rcast;

  	int rc_ratio;
  	int bc_threshold;

  };

  static struct tipc_bc_base *tipc_bc_base(struct net *net)
  {
  	return tipc_net(net)->bcbase;
  }

  /* tipc_bcast_get_mtu(): -get the MTU currently used by broadcast link
   * Note: the MTU is decremented to give room for a tunnel header, in
   * case the message needs to be sent as replicast
   */

  int tipc_bcast_get_mtu(struct net *net)

  {

  	return tipc_link_mtu(tipc_bc_sndlink(net)) - INT_H_SIZE;

  }

  void tipc_bcast_disable_rcast(struct net *net)
  {
  	tipc_bc_base(net)->rcast_support = false;
  }
  
  static void tipc_bcbase_calc_bc_threshold(struct net *net)
  {
  	struct tipc_bc_base *bb = tipc_bc_base(net);
  	int cluster_size = tipc_link_bc_peers(tipc_bc_sndlink(net));
  
  	bb->bc_threshold = 1 + (cluster_size * bb->rc_ratio / 100);
  }

  /* tipc_bcbase_select_primary(): find a bearer with links to all destinations,
   *                               if any, and make it primary bearer
   */
  static void tipc_bcbase_select_primary(struct net *net)
  {
  	struct tipc_bc_base *bb = tipc_bc_base(net);
  	int all_dests =  tipc_link_bc_peers(bb->link);

  	int i, mtu, prim;

  
  	bb->primary_bearer = INVALID_BEARER_ID;

  	bb->bcast_support = true;

  
  	if (!all_dests)
  		return;
  
  	for (i = 0; i < MAX_BEARERS; i++) {

  		if (!bb->dests[i])
  			continue;
  
  		mtu = tipc_bearer_mtu(net, i);
  		if (mtu < tipc_link_mtu(bb->link))
  			tipc_link_set_mtu(bb->link, mtu);

  		bb->bcast_support &= tipc_bearer_bcast_support(net, i);

  		if (bb->dests[i] < all_dests)
  			continue;
  
  		bb->primary_bearer = i;
  
  		/* Reduce risk that all nodes select same primary */
  		if ((i ^ tipc_own_addr(net)) & 1)
  			break;
  	}

  	prim = bb->primary_bearer;
  	if (prim != INVALID_BEARER_ID)
  		bb->bcast_support = tipc_bearer_bcast_support(net, prim);

  }
  
  void tipc_bcast_inc_bearer_dst_cnt(struct net *net, int bearer_id)
  {
  	struct tipc_bc_base *bb = tipc_bc_base(net);
  
  	tipc_bcast_lock(net);
  	bb->dests[bearer_id]++;
  	tipc_bcbase_select_primary(net);
  	tipc_bcast_unlock(net);
  }
  
  void tipc_bcast_dec_bearer_dst_cnt(struct net *net, int bearer_id)
  {
  	struct tipc_bc_base *bb = tipc_bc_base(net);
  
  	tipc_bcast_lock(net);
  	bb->dests[bearer_id]--;
  	tipc_bcbase_select_primary(net);
  	tipc_bcast_unlock(net);
  }

  /* tipc_bcbase_xmit - broadcast a packet queue across one or more bearers
   *
   * Note that number of reachable destinations, as indicated in the dests[]
   * array, may transitionally differ from the number of destinations indicated
   * in each sent buffer. We can sustain this. Excess destination nodes will
   * drop and never acknowledge the unexpected packets, and missing destinations
   * will either require retransmission (if they are just about to be added to
   * the bearer), or be removed from the buffer's 'ackers' counter (if they
   * just went down)
   */
  static void tipc_bcbase_xmit(struct net *net, struct sk_buff_head *xmitq)
  {
  	int bearer_id;
  	struct tipc_bc_base *bb = tipc_bc_base(net);
  	struct sk_buff *skb, *_skb;
  	struct sk_buff_head _xmitq;
  
  	if (skb_queue_empty(xmitq))
  		return;
  
  	/* The typical case: at least one bearer has links to all nodes */
  	bearer_id = bb->primary_bearer;
  	if (bearer_id >= 0) {
  		tipc_bearer_bc_xmit(net, bearer_id, xmitq);
  		return;
  	}
  
  	/* We have to transmit across all bearers */

  	__skb_queue_head_init(&_xmitq);

  	for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
  		if (!bb->dests[bearer_id])
  			continue;
  
  		skb_queue_walk(xmitq, skb) {
  			_skb = pskb_copy_for_clone(skb, GFP_ATOMIC);
  			if (!_skb)
  				break;
  			__skb_queue_tail(&_xmitq, _skb);
  		}
  		tipc_bearer_bc_xmit(net, bearer_id, &_xmitq);
  	}
  	__skb_queue_purge(xmitq);
  	__skb_queue_purge(&_xmitq);
  }

  static void tipc_bcast_select_xmit_method(struct net *net, int dests,
  					  struct tipc_mc_method *method)
  {
  	struct tipc_bc_base *bb = tipc_bc_base(net);
  	unsigned long exp = method->expires;
  
  	/* Broadcast supported by used bearer/bearers? */
  	if (!bb->bcast_support) {
  		method->rcast = true;
  		return;
  	}
  	/* Any destinations which don't support replicast ? */
  	if (!bb->rcast_support) {
  		method->rcast = false;
  		return;
  	}
  	/* Can current method be changed ? */
  	method->expires = jiffies + TIPC_METHOD_EXPIRE;

  	if (method->mandatory)

  		return;

  	if (!(tipc_net(net)->capabilities & TIPC_MCAST_RBCTL) &&
  	    time_before(jiffies, exp))
  		return;
  
  	/* Configuration as force 'broadcast' method */
  	if (bb->force_bcast) {
  		method->rcast = false;
  		return;
  	}
  	/* Configuration as force 'replicast' method */
  	if (bb->force_rcast) {
  		method->rcast = true;
  		return;
  	}
  	/* Configuration as 'autoselect' or default method */

  	/* Determine method to use now */
  	method->rcast = dests <= bb->bc_threshold;
  }

  /* tipc_bcast_xmit - broadcast the buffer chain to all external nodes

   * @net: the applicable net namespace

   * @pkts: chain of buffers containing message
   * @cong_link_cnt: set to 1 if broadcast link is congested, otherwise 0

   * Consumes the buffer chain.

   * Returns 0 if success, otherwise errno: -EHOSTUNREACH,-EMSGSIZE

   */

  static int tipc_bcast_xmit(struct net *net, struct sk_buff_head *pkts,
  			   u16 *cong_link_cnt)

  {

  	struct tipc_link *l = tipc_bc_sndlink(net);

  	struct sk_buff_head xmitq;

  	int rc = 0;

  	__skb_queue_head_init(&xmitq);

  	tipc_bcast_lock(net);
  	if (tipc_link_bc_peers(l))

  		rc = tipc_link_xmit(l, pkts, &xmitq);

  	tipc_bcast_unlock(net);

  	tipc_bcbase_xmit(net, &xmitq);
  	__skb_queue_purge(pkts);
  	if (rc == -ELINKCONG) {
  		*cong_link_cnt = 1;
  		rc = 0;
  	}
  	return rc;
  }
  
  /* tipc_rcast_xmit - replicate and send a message to given destination nodes
   * @net: the applicable net namespace
   * @pkts: chain of buffers containing message
   * @dests: list of destination nodes
   * @cong_link_cnt: returns number of congested links
   * @cong_links: returns identities of congested links
   * Returns 0 if success, otherwise errno
   */
  static int tipc_rcast_xmit(struct net *net, struct sk_buff_head *pkts,
  			   struct tipc_nlist *dests, u16 *cong_link_cnt)
  {

  	struct tipc_dest *dst, *tmp;

  	struct sk_buff_head _pkts;

  	u32 dnode, selector;

  
  	selector = msg_link_selector(buf_msg(skb_peek(pkts)));

  	__skb_queue_head_init(&_pkts);

  	list_for_each_entry_safe(dst, tmp, &dests->list, list) {
  		dnode = dst->node;
  		if (!tipc_msg_pskb_copy(dnode, pkts, &_pkts))

  			return -ENOMEM;

  		/* Any other return value than -ELINKCONG is ignored */

  		if (tipc_node_xmit(net, &_pkts, dnode, selector) == -ELINKCONG)

  			(*cong_link_cnt)++;

  	}

  	return 0;
  }

  /* tipc_mcast_send_sync - deliver a dummy message with SYN bit
   * @net: the applicable net namespace
   * @skb: socket buffer to copy
   * @method: send method to be used
   * @dests: destination nodes for message.

   * Returns 0 if success, otherwise errno
   */
  static int tipc_mcast_send_sync(struct net *net, struct sk_buff *skb,
  				struct tipc_mc_method *method,

  				struct tipc_nlist *dests)

  {
  	struct tipc_msg *hdr, *_hdr;
  	struct sk_buff_head tmpq;
  	struct sk_buff *_skb;

  	u16 cong_link_cnt;
  	int rc = 0;

  
  	/* Is a cluster supporting with new capabilities ? */
  	if (!(tipc_net(net)->capabilities & TIPC_MCAST_RBCTL))
  		return 0;
  
  	hdr = buf_msg(skb);
  	if (msg_user(hdr) == MSG_FRAGMENTER)

  		hdr = msg_inner_hdr(hdr);

  	if (msg_type(hdr) != TIPC_MCAST_MSG)
  		return 0;
  
  	/* Allocate dummy message */
  	_skb = tipc_buf_acquire(MCAST_H_SIZE, GFP_KERNEL);

  	if (!_skb)

  		return -ENOMEM;
  
  	/* Preparing for 'synching' header */
  	msg_set_syn(hdr, 1);
  
  	/* Copy skb's header into a dummy header */
  	skb_copy_to_linear_data(_skb, hdr, MCAST_H_SIZE);
  	skb_orphan(_skb);
  
  	/* Reverse method for dummy message */
  	_hdr = buf_msg(_skb);
  	msg_set_size(_hdr, MCAST_H_SIZE);
  	msg_set_is_rcast(_hdr, !msg_is_rcast(hdr));

  	msg_set_errcode(_hdr, TIPC_ERR_NO_PORT);

  	__skb_queue_head_init(&tmpq);

  	__skb_queue_tail(&tmpq, _skb);
  	if (method->rcast)

  		rc = tipc_bcast_xmit(net, &tmpq, &cong_link_cnt);

  	else

  		rc = tipc_rcast_xmit(net, &tmpq, dests, &cong_link_cnt);

  
  	/* This queue should normally be empty by now */
  	__skb_queue_purge(&tmpq);

  	return rc;

  }

  /* tipc_mcast_xmit - deliver message to indicated destination nodes
   *                   and to identified node local sockets
   * @net: the applicable net namespace
   * @pkts: chain of buffers containing message

   * @method: send method to be used
   * @dests: destination nodes for message.

   * @cong_link_cnt: returns number of encountered congested destination links

   * Consumes buffer chain.
   * Returns 0 if success, otherwise errno
   */
  int tipc_mcast_xmit(struct net *net, struct sk_buff_head *pkts,

  		    struct tipc_mc_method *method, struct tipc_nlist *dests,
  		    u16 *cong_link_cnt)

  {

  	struct sk_buff_head inputq, localq;

  	bool rcast = method->rcast;
  	struct tipc_msg *hdr;
  	struct sk_buff *skb;

  	int rc = 0;
  
  	skb_queue_head_init(&inputq);

  	__skb_queue_head_init(&localq);

  
  	/* Clone packets before they are consumed by next call */
  	if (dests->local && !tipc_msg_reassemble(pkts, &localq)) {
  		rc = -ENOMEM;
  		goto exit;
  	}

  	/* Send according to determined transmit method */

  	if (dests->remote) {

  		tipc_bcast_select_xmit_method(net, dests->remote, method);

  
  		skb = skb_peek(pkts);
  		hdr = buf_msg(skb);
  		if (msg_user(hdr) == MSG_FRAGMENTER)

  			hdr = msg_inner_hdr(hdr);

  		msg_set_is_rcast(hdr, method->rcast);
  
  		/* Switch method ? */

  		if (rcast != method->rcast) {
  			rc = tipc_mcast_send_sync(net, skb, method, dests);
  			if (unlikely(rc)) {
  				pr_err("Unable to send SYN: method %d, rc %d
  ",
  				       rcast, rc);
  				goto exit;
  			}
  		}

  		if (method->rcast)

  			rc = tipc_rcast_xmit(net, pkts, dests, cong_link_cnt);
  		else
  			rc = tipc_bcast_xmit(net, pkts, cong_link_cnt);
  	}

  	if (dests->local) {
  		tipc_loopback_trace(net, &localq);

  		tipc_sk_mcast_rcv(net, &localq, &inputq);

  	}

  exit:

  	/* This queue should normally be empty by now */

  	__skb_queue_purge(pkts);

  	return rc;

  }

  
  /* tipc_bcast_rcv - receive a broadcast packet, and deliver to rcv link
   *
   * RCU is locked, no other locks set
   */
  int tipc_bcast_rcv(struct net *net, struct tipc_link *l, struct sk_buff *skb)
  {
  	struct tipc_msg *hdr = buf_msg(skb);
  	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
  	struct sk_buff_head xmitq;
  	int rc;
  
  	__skb_queue_head_init(&xmitq);
  
  	if (msg_mc_netid(hdr) != tipc_netid(net) || !tipc_link_is_up(l)) {
  		kfree_skb(skb);
  		return 0;
  	}
  
  	tipc_bcast_lock(net);
  	if (msg_user(hdr) == BCAST_PROTOCOL)
  		rc = tipc_link_bc_nack_rcv(l, skb, &xmitq);
  	else
  		rc = tipc_link_rcv(l, skb, NULL);
  	tipc_bcast_unlock(net);

  	tipc_bcbase_xmit(net, &xmitq);

  
  	/* Any socket wakeup messages ? */
  	if (!skb_queue_empty(inputq))
  		tipc_sk_rcv(net, inputq);
  
  	return rc;
  }
  
  /* tipc_bcast_ack_rcv - receive and handle a broadcast acknowledge
   *
   * RCU is locked, no other locks set
   */

  void tipc_bcast_ack_rcv(struct net *net, struct tipc_link *l,
  			struct tipc_msg *hdr)

  {
  	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;

  	u16 acked = msg_bcast_ack(hdr);

  	struct sk_buff_head xmitq;

  	/* Ignore bc acks sent by peer before bcast synch point was received */
  	if (msg_bc_ack_invalid(hdr))
  		return;

  	__skb_queue_head_init(&xmitq);
  
  	tipc_bcast_lock(net);
  	tipc_link_bc_ack_rcv(l, acked, &xmitq);
  	tipc_bcast_unlock(net);

  	tipc_bcbase_xmit(net, &xmitq);

  
  	/* Any socket wakeup messages ? */
  	if (!skb_queue_empty(inputq))
  		tipc_sk_rcv(net, inputq);
  }
  
  /* tipc_bcast_synch_rcv -  check and update rcv link with peer's send state
   *
   * RCU is locked, no other locks set
   */

  int tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l,
  			struct tipc_msg *hdr)

  {
  	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
  	struct sk_buff_head xmitq;

  	int rc = 0;

  
  	__skb_queue_head_init(&xmitq);
  
  	tipc_bcast_lock(net);

  	if (msg_type(hdr) != STATE_MSG) {
  		tipc_link_bc_init_rcv(l, hdr);
  	} else if (!msg_bc_ack_invalid(hdr)) {

  		tipc_link_bc_ack_rcv(l, msg_bcast_ack(hdr), &xmitq);

  		rc = tipc_link_bc_sync_rcv(l, hdr, &xmitq);

  	}
  	tipc_bcast_unlock(net);

  	tipc_bcbase_xmit(net, &xmitq);

  
  	/* Any socket wakeup messages ? */
  	if (!skb_queue_empty(inputq))
  		tipc_sk_rcv(net, inputq);

  	return rc;

  }
  
  /* tipc_bcast_add_peer - add a peer node to broadcast link and bearer
   *
   * RCU is locked, node lock is set
   */

  void tipc_bcast_add_peer(struct net *net, struct tipc_link *uc_l,

  			 struct sk_buff_head *xmitq)
  {

  	struct tipc_link *snd_l = tipc_bc_sndlink(net);

  	tipc_bcast_lock(net);

  	tipc_link_add_bc_peer(snd_l, uc_l, xmitq);

  	tipc_bcbase_select_primary(net);

  	tipc_bcbase_calc_bc_threshold(net);

  	tipc_bcast_unlock(net);

  }
  
  /* tipc_bcast_remove_peer - remove a peer node from broadcast link and bearer
   *
   * RCU is locked, node lock is set
   */

  void tipc_bcast_remove_peer(struct net *net, struct tipc_link *rcv_l)

  {

  	struct tipc_link *snd_l = tipc_bc_sndlink(net);

  	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;

  	struct sk_buff_head xmitq;
  
  	__skb_queue_head_init(&xmitq);

  	tipc_bcast_lock(net);

  	tipc_link_remove_bc_peer(snd_l, rcv_l, &xmitq);

  	tipc_bcbase_select_primary(net);

  	tipc_bcbase_calc_bc_threshold(net);

  	tipc_bcast_unlock(net);

  	tipc_bcbase_xmit(net, &xmitq);

  
  	/* Any socket wakeup messages ? */
  	if (!skb_queue_empty(inputq))
  		tipc_sk_rcv(net, inputq);
  }

  int tipc_bclink_reset_stats(struct net *net)

  {

  	struct tipc_link *l = tipc_bc_sndlink(net);

  	if (!l)

  		return -ENOPROTOOPT;

  	tipc_bcast_lock(net);

  	tipc_link_reset_stats(l);

  	tipc_bcast_unlock(net);

  	return 0;

  }

  static int tipc_bc_link_set_queue_limits(struct net *net, u32 limit)

  {

  	struct tipc_link *l = tipc_bc_sndlink(net);

  	if (!l)

  		return -ENOPROTOOPT;

  	if (limit < BCLINK_WIN_MIN)
  		limit = BCLINK_WIN_MIN;
  	if (limit > TIPC_MAX_LINK_WIN)

  		return -EINVAL;

  	tipc_bcast_lock(net);
  	tipc_link_set_queue_limits(l, limit);
  	tipc_bcast_unlock(net);

  	return 0;

  }

  static int tipc_bc_link_set_broadcast_mode(struct net *net, u32 bc_mode)
  {
  	struct tipc_bc_base *bb = tipc_bc_base(net);
  
  	switch (bc_mode) {
  	case BCLINK_MODE_BCAST:
  		if (!bb->bcast_support)
  			return -ENOPROTOOPT;
  
  		bb->force_bcast = true;
  		bb->force_rcast = false;
  		break;
  	case BCLINK_MODE_RCAST:
  		if (!bb->rcast_support)
  			return -ENOPROTOOPT;
  
  		bb->force_bcast = false;
  		bb->force_rcast = true;
  		break;
  	case BCLINK_MODE_SEL:
  		if (!bb->bcast_support || !bb->rcast_support)
  			return -ENOPROTOOPT;
  
  		bb->force_bcast = false;
  		bb->force_rcast = false;
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static int tipc_bc_link_set_broadcast_ratio(struct net *net, u32 bc_ratio)
  {
  	struct tipc_bc_base *bb = tipc_bc_base(net);
  
  	if (!bb->bcast_support || !bb->rcast_support)
  		return -ENOPROTOOPT;
  
  	if (bc_ratio > 100 || bc_ratio <= 0)
  		return -EINVAL;
  
  	bb->rc_ratio = bc_ratio;
  	tipc_bcast_lock(net);
  	tipc_bcbase_calc_bc_threshold(net);
  	tipc_bcast_unlock(net);
  
  	return 0;
  }

  int tipc_nl_bc_link_set(struct net *net, struct nlattr *attrs[])
  {
  	int err;
  	u32 win;

  	u32 bc_mode;
  	u32 bc_ratio;

  	struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
  
  	if (!attrs[TIPC_NLA_LINK_PROP])
  		return -EINVAL;
  
  	err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP], props);
  	if (err)
  		return err;

  	if (!props[TIPC_NLA_PROP_WIN] &&
  	    !props[TIPC_NLA_PROP_BROADCAST] &&
  	    !props[TIPC_NLA_PROP_BROADCAST_RATIO]) {

  		return -EOPNOTSUPP;

  	}
  
  	if (props[TIPC_NLA_PROP_BROADCAST]) {
  		bc_mode = nla_get_u32(props[TIPC_NLA_PROP_BROADCAST]);
  		err = tipc_bc_link_set_broadcast_mode(net, bc_mode);
  	}

  	if (!err && props[TIPC_NLA_PROP_BROADCAST_RATIO]) {
  		bc_ratio = nla_get_u32(props[TIPC_NLA_PROP_BROADCAST_RATIO]);
  		err = tipc_bc_link_set_broadcast_ratio(net, bc_ratio);
  	}

  	if (!err && props[TIPC_NLA_PROP_WIN]) {
  		win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
  		err = tipc_bc_link_set_queue_limits(net, win);
  	}
  
  	return err;

  }

  int tipc_bcast_init(struct net *net)

  {

  	struct tipc_net *tn = tipc_net(net);

  	struct tipc_bc_base *bb = NULL;
  	struct tipc_link *l = NULL;

  	bb = kzalloc(sizeof(*bb), GFP_KERNEL);

  	if (!bb)
  		goto enomem;
  	tn->bcbase = bb;

  	spin_lock_init(&tipc_net(net)->bclock);

  	if (!tipc_link_bc_create(net, 0, 0,

  				 FB_MTU,

  				 BCLINK_WIN_DEFAULT,

  				 0,

  				 &bb->inputq,

  				 NULL,

  				 NULL,

  				 &l))
  		goto enomem;
  	bb->link = l;
  	tn->bcl = l;

  	bb->rc_ratio = 10;

  	bb->rcast_support = true;

  	return 0;

  enomem:

  	kfree(bb);
  	kfree(l);
  	return -ENOMEM;

  }

  void tipc_bcast_stop(struct net *net)

  {

  	struct tipc_net *tn = net_generic(net, tipc_net_id);

  	synchronize_net();

  	kfree(tn->bcbase);

  	kfree(tn->bcl);

  }

  
  void tipc_nlist_init(struct tipc_nlist *nl, u32 self)
  {
  	memset(nl, 0, sizeof(*nl));
  	INIT_LIST_HEAD(&nl->list);
  	nl->self = self;
  }
  
  void tipc_nlist_add(struct tipc_nlist *nl, u32 node)
  {
  	if (node == nl->self)
  		nl->local = true;

  	else if (tipc_dest_push(&nl->list, node, 0))

  		nl->remote++;
  }
  
  void tipc_nlist_del(struct tipc_nlist *nl, u32 node)
  {
  	if (node == nl->self)
  		nl->local = false;

  	else if (tipc_dest_del(&nl->list, node, 0))

  		nl->remote--;
  }
  
  void tipc_nlist_purge(struct tipc_nlist *nl)
  {

  	tipc_dest_list_purge(&nl->list);

  	nl->remote = 0;

  	nl->local = false;

  }

  
  u32 tipc_bcast_get_broadcast_mode(struct net *net)
  {
  	struct tipc_bc_base *bb = tipc_bc_base(net);
  
  	if (bb->force_bcast)
  		return BCLINK_MODE_BCAST;
  
  	if (bb->force_rcast)
  		return BCLINK_MODE_RCAST;
  
  	if (bb->bcast_support && bb->rcast_support)
  		return BCLINK_MODE_SEL;
  
  	return 0;
  }
  
  u32 tipc_bcast_get_broadcast_ratio(struct net *net)
  {
  	struct tipc_bc_base *bb = tipc_bc_base(net);
  
  	return bb->rc_ratio;
  }

  void tipc_mcast_filter_msg(struct net *net, struct sk_buff_head *defq,

  			   struct sk_buff_head *inputq)
  {
  	struct sk_buff *skb, *_skb, *tmp;
  	struct tipc_msg *hdr, *_hdr;
  	bool match = false;
  	u32 node, port;
  
  	skb = skb_peek(inputq);

  	if (!skb)
  		return;

  	hdr = buf_msg(skb);
  
  	if (likely(!msg_is_syn(hdr) && skb_queue_empty(defq)))
  		return;
  
  	node = msg_orignode(hdr);

  	if (node == tipc_own_addr(net))
  		return;

  	port = msg_origport(hdr);
  
  	/* Has the twin SYN message already arrived ? */
  	skb_queue_walk(defq, _skb) {
  		_hdr = buf_msg(_skb);
  		if (msg_orignode(_hdr) != node)
  			continue;
  		if (msg_origport(_hdr) != port)
  			continue;
  		match = true;
  		break;
  	}
  
  	if (!match) {
  		if (!msg_is_syn(hdr))
  			return;
  		__skb_dequeue(inputq);
  		__skb_queue_tail(defq, skb);
  		return;
  	}
  
  	/* Deliver non-SYN message from other link, otherwise queue it */
  	if (!msg_is_syn(hdr)) {
  		if (msg_is_rcast(hdr) != msg_is_rcast(_hdr))
  			return;
  		__skb_dequeue(inputq);
  		__skb_queue_tail(defq, skb);
  		return;
  	}
  
  	/* Queue non-SYN/SYN message from same link */
  	if (msg_is_rcast(hdr) == msg_is_rcast(_hdr)) {
  		__skb_dequeue(inputq);
  		__skb_queue_tail(defq, skb);
  		return;
  	}
  
  	/* Matching SYN messages => return the one with data, if any */
  	__skb_unlink(_skb, defq);
  	if (msg_data_sz(hdr)) {
  		kfree_skb(_skb);
  	} else {
  		__skb_dequeue(inputq);
  		kfree_skb(skb);
  		__skb_queue_tail(inputq, _skb);
  	}
  
  	/* Deliver subsequent non-SYN messages from same peer */
  	skb_queue_walk_safe(defq, _skb, tmp) {
  		_hdr = buf_msg(_skb);
  		if (msg_orignode(_hdr) != node)
  			continue;
  		if (msg_origport(_hdr) != port)
  			continue;
  		if (msg_is_syn(_hdr))
  			break;
  		__skb_unlink(_skb, defq);
  		__skb_queue_tail(inputq, _skb);
  	}
  }