Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 864 insertions, 0 deletions

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
new file mode 100644
index 000000000..593846d25
--- /dev/null
+++ b/net/tipc/bcast.c
@@ -0,0 +1,864 @@
+/*
+ * 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";
+unsigned long sysctl_tipc_bc_retruni __read_mostly;
+
+/**
+ * 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_mss(tipc_bc_sndlink(net));
+}
+
+void tipc_bcast_toggle_rcast(struct net *net, bool supp)
+{
+	tipc_bc_base(net)->rcast_support = supp;
+}
+
+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 max_win = tipc_link_max_win(bb->link);
+	int min_win = tipc_link_min_win(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);
+			tipc_link_set_queue_limits(bb->link,
+						   min_win,
+						   max_win);
+		}
+		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
+ */
+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\n",
+				       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, 0, NULL, &xmitq, NULL);
+	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 *retrq)
+{
+	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
+	struct tipc_gap_ack_blks *ga;
+	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_get_gap_ack_blks(&ga, l, hdr, false);
+		if (!sysctl_tipc_bc_retruni)
+			retrq = &xmitq;
+		rc = tipc_link_bc_ack_rcv(l, msg_bcast_ack(hdr),
+					  msg_bc_gap(hdr), ga, &xmitq,
+					  retrq);
+		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)
+{
+	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 max_win)
+{
+	struct tipc_link *l = tipc_bc_sndlink(net);
+
+	if (!l)
+		return -ENOPROTOOPT;
+	if (max_win < BCLINK_WIN_MIN)
+		max_win = BCLINK_WIN_MIN;
+	if (max_win > TIPC_MAX_LINK_WIN)
+		return -EINVAL;
+	tipc_bcast_lock(net);
+	tipc_link_set_queue_limits(l, tipc_link_min_win(l), max_win);
+	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, NULL,
+				 one_page_mtu,
+				 BCLINK_WIN_DEFAULT,
+				 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_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);
+	}
+}