Initial import

1 files changed, 986 insertions, 0 deletions

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
new file mode 100644
index 000000000..c5cbdcb1f
--- /dev/null
+++ b/net/tipc/bcast.c
@@ -0,0 +1,986 @@
+/*
+ * net/tipc/bcast.c: TIPC broadcast code
+ *
+ * Copyright (c) 2004-2006, 2014-2015, 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 "socket.h"
+#include "msg.h"
+#include "bcast.h"
+#include "name_distr.h"
+#include "core.h"
+
+#define	MAX_PKT_DEFAULT_MCAST	1500	/* bcast link max packet size (fixed) */
+#define	BCLINK_WIN_DEFAULT	20	/* bcast link window size (default) */
+
+const char tipc_bclink_name[] = "broadcast-link";
+
+static void tipc_nmap_diff(struct tipc_node_map *nm_a,
+			   struct tipc_node_map *nm_b,
+			   struct tipc_node_map *nm_diff);
+static void tipc_nmap_add(struct tipc_node_map *nm_ptr, u32 node);
+static void tipc_nmap_remove(struct tipc_node_map *nm_ptr, u32 node);
+
+static void tipc_bclink_lock(struct net *net)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+
+	spin_lock_bh(&tn->bclink->lock);
+}
+
+static void tipc_bclink_unlock(struct net *net)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+
+	spin_unlock_bh(&tn->bclink->lock);
+}
+
+void tipc_bclink_input(struct net *net)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+
+	tipc_sk_mcast_rcv(net, &tn->bclink->arrvq, &tn->bclink->inputq);
+}
+
+uint  tipc_bclink_get_mtu(void)
+{
+	return MAX_PKT_DEFAULT_MCAST;
+}
+
+static u32 bcbuf_acks(struct sk_buff *buf)
+{
+	return (u32)(unsigned long)TIPC_SKB_CB(buf)->handle;
+}
+
+static void bcbuf_set_acks(struct sk_buff *buf, u32 acks)
+{
+	TIPC_SKB_CB(buf)->handle = (void *)(unsigned long)acks;
+}
+
+static void bcbuf_decr_acks(struct sk_buff *buf)
+{
+	bcbuf_set_acks(buf, bcbuf_acks(buf) - 1);
+}
+
+void tipc_bclink_add_node(struct net *net, u32 addr)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+
+	tipc_bclink_lock(net);
+	tipc_nmap_add(&tn->bclink->bcast_nodes, addr);
+	tipc_bclink_unlock(net);
+}
+
+void tipc_bclink_remove_node(struct net *net, u32 addr)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+
+	tipc_bclink_lock(net);
+	tipc_nmap_remove(&tn->bclink->bcast_nodes, addr);
+	tipc_bclink_unlock(net);
+}
+
+static void bclink_set_last_sent(struct net *net)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_link *bcl = tn->bcl;
+	struct sk_buff *skb = skb_peek(&bcl->backlogq);
+
+	if (skb)
+		bcl->fsm_msg_cnt = mod(buf_seqno(skb) - 1);
+	else
+		bcl->fsm_msg_cnt = mod(bcl->next_out_no - 1);
+}
+
+u32 tipc_bclink_get_last_sent(struct net *net)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+
+	return tn->bcl->fsm_msg_cnt;
+}
+
+static void bclink_update_last_sent(struct tipc_node *node, u32 seqno)
+{
+	node->bclink.last_sent = less_eq(node->bclink.last_sent, seqno) ?
+						seqno : node->bclink.last_sent;
+}
+
+/**
+ * tipc_bclink_retransmit_to - get most recent node to request retransmission
+ *
+ * Called with bclink_lock locked
+ */
+struct tipc_node *tipc_bclink_retransmit_to(struct net *net)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+
+	return tn->bclink->retransmit_to;
+}
+
+/**
+ * bclink_retransmit_pkt - retransmit broadcast packets
+ * @after: sequence number of last packet to *not* retransmit
+ * @to: sequence number of last packet to retransmit
+ *
+ * Called with bclink_lock locked
+ */
+static void bclink_retransmit_pkt(struct tipc_net *tn, u32 after, u32 to)
+{
+	struct sk_buff *skb;
+	struct tipc_link *bcl = tn->bcl;
+
+	skb_queue_walk(&bcl->transmq, skb) {
+		if (more(buf_seqno(skb), after)) {
+			tipc_link_retransmit(bcl, skb, mod(to - after));
+			break;
+		}
+	}
+}
+
+/**
+ * tipc_bclink_wakeup_users - wake up pending users
+ *
+ * Called with no locks taken
+ */
+void tipc_bclink_wakeup_users(struct net *net)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+
+	tipc_sk_rcv(net, &tn->bclink->link.wakeupq);
+}
+
+/**
+ * tipc_bclink_acknowledge - handle acknowledgement of broadcast packets
+ * @n_ptr: node that sent acknowledgement info
+ * @acked: broadcast sequence # that has been acknowledged
+ *
+ * Node is locked, bclink_lock unlocked.
+ */
+void tipc_bclink_acknowledge(struct tipc_node *n_ptr, u32 acked)
+{
+	struct sk_buff *skb, *tmp;
+	unsigned int released = 0;
+	struct net *net = n_ptr->net;
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+
+	if (unlikely(!n_ptr->bclink.recv_permitted))
+		return;
+
+	tipc_bclink_lock(net);
+
+	/* Bail out if tx queue is empty (no clean up is required) */
+	skb = skb_peek(&tn->bcl->transmq);
+	if (!skb)
+		goto exit;
+
+	/* Determine which messages need to be acknowledged */
+	if (acked == INVALID_LINK_SEQ) {
+		/*
+		 * Contact with specified node has been lost, so need to
+		 * acknowledge sent messages only (if other nodes still exist)
+		 * or both sent and unsent messages (otherwise)
+		 */
+		if (tn->bclink->bcast_nodes.count)
+			acked = tn->bcl->fsm_msg_cnt;
+		else
+			acked = tn->bcl->next_out_no;
+	} else {
+		/*
+		 * Bail out if specified sequence number does not correspond
+		 * to a message that has been sent and not yet acknowledged
+		 */
+		if (less(acked, buf_seqno(skb)) ||
+		    less(tn->bcl->fsm_msg_cnt, acked) ||
+		    less_eq(acked, n_ptr->bclink.acked))
+			goto exit;
+	}
+
+	/* Skip over packets that node has previously acknowledged */
+	skb_queue_walk(&tn->bcl->transmq, skb) {
+		if (more(buf_seqno(skb), n_ptr->bclink.acked))
+			break;
+	}
+
+	/* Update packets that node is now acknowledging */
+	skb_queue_walk_from_safe(&tn->bcl->transmq, skb, tmp) {
+		if (more(buf_seqno(skb), acked))
+			break;
+		bcbuf_decr_acks(skb);
+		bclink_set_last_sent(net);
+		if (bcbuf_acks(skb) == 0) {
+			__skb_unlink(skb, &tn->bcl->transmq);
+			kfree_skb(skb);
+			released = 1;
+		}
+	}
+	n_ptr->bclink.acked = acked;
+
+	/* Try resolving broadcast link congestion, if necessary */
+	if (unlikely(skb_peek(&tn->bcl->backlogq))) {
+		tipc_link_push_packets(tn->bcl);
+		bclink_set_last_sent(net);
+	}
+	if (unlikely(released && !skb_queue_empty(&tn->bcl->wakeupq)))
+		n_ptr->action_flags |= TIPC_WAKEUP_BCAST_USERS;
+exit:
+	tipc_bclink_unlock(net);
+}
+
+/**
+ * tipc_bclink_update_link_state - update broadcast link state
+ *
+ * RCU and node lock set
+ */
+void tipc_bclink_update_link_state(struct tipc_node *n_ptr,
+				   u32 last_sent)
+{
+	struct sk_buff *buf;
+	struct net *net = n_ptr->net;
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+
+	/* Ignore "stale" link state info */
+	if (less_eq(last_sent, n_ptr->bclink.last_in))
+		return;
+
+	/* Update link synchronization state; quit if in sync */
+	bclink_update_last_sent(n_ptr, last_sent);
+
+	if (n_ptr->bclink.last_sent == n_ptr->bclink.last_in)
+		return;
+
+	/* Update out-of-sync state; quit if loss is still unconfirmed */
+	if ((++n_ptr->bclink.oos_state) == 1) {
+		if (n_ptr->bclink.deferred_size < (TIPC_MIN_LINK_WIN / 2))
+			return;
+		n_ptr->bclink.oos_state++;
+	}
+
+	/* Don't NACK if one has been recently sent (or seen) */
+	if (n_ptr->bclink.oos_state & 0x1)
+		return;
+
+	/* Send NACK */
+	buf = tipc_buf_acquire(INT_H_SIZE);
+	if (buf) {
+		struct tipc_msg *msg = buf_msg(buf);
+		struct sk_buff *skb = skb_peek(&n_ptr->bclink.deferdq);
+		u32 to = skb ? buf_seqno(skb) - 1 : n_ptr->bclink.last_sent;
+
+		tipc_msg_init(tn->own_addr, msg, BCAST_PROTOCOL, STATE_MSG,
+			      INT_H_SIZE, n_ptr->addr);
+		msg_set_non_seq(msg, 1);
+		msg_set_mc_netid(msg, tn->net_id);
+		msg_set_bcast_ack(msg, n_ptr->bclink.last_in);
+		msg_set_bcgap_after(msg, n_ptr->bclink.last_in);
+		msg_set_bcgap_to(msg, to);
+
+		tipc_bclink_lock(net);
+		tipc_bearer_send(net, MAX_BEARERS, buf, NULL);
+		tn->bcl->stats.sent_nacks++;
+		tipc_bclink_unlock(net);
+		kfree_skb(buf);
+
+		n_ptr->bclink.oos_state++;
+	}
+}
+
+/**
+ * bclink_peek_nack - monitor retransmission requests sent by other nodes
+ *
+ * Delay any upcoming NACK by this node if another node has already
+ * requested the first message this node is going to ask for.
+ */
+static void bclink_peek_nack(struct net *net, struct tipc_msg *msg)
+{
+	struct tipc_node *n_ptr = tipc_node_find(net, msg_destnode(msg));
+
+	if (unlikely(!n_ptr))
+		return;
+
+	tipc_node_lock(n_ptr);
+	if (n_ptr->bclink.recv_permitted &&
+	    (n_ptr->bclink.last_in != n_ptr->bclink.last_sent) &&
+	    (n_ptr->bclink.last_in == msg_bcgap_after(msg)))
+		n_ptr->bclink.oos_state = 2;
+	tipc_node_unlock(n_ptr);
+	tipc_node_put(n_ptr);
+}
+
+/* tipc_bclink_xmit - deliver buffer chain to all nodes in cluster
+ *                    and to identified node local sockets
+ * @net: the applicable net namespace
+ * @list: chain of buffers containing message
+ * Consumes the buffer chain, except when returning -ELINKCONG
+ * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
+ */
+int tipc_bclink_xmit(struct net *net, struct sk_buff_head *list)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_link *bcl = tn->bcl;
+	struct tipc_bclink *bclink = tn->bclink;
+	int rc = 0;
+	int bc = 0;
+	struct sk_buff *skb;
+	struct sk_buff_head arrvq;
+	struct sk_buff_head inputq;
+
+	/* Prepare clone of message for local node */
+	skb = tipc_msg_reassemble(list);
+	if (unlikely(!skb)) {
+		__skb_queue_purge(list);
+		return -EHOSTUNREACH;
+	}
+	/* Broadcast to all nodes */
+	if (likely(bclink)) {
+		tipc_bclink_lock(net);
+		if (likely(bclink->bcast_nodes.count)) {
+			rc = __tipc_link_xmit(net, bcl, list);
+			if (likely(!rc)) {
+				u32 len = skb_queue_len(&bcl->transmq);
+
+				bclink_set_last_sent(net);
+				bcl->stats.queue_sz_counts++;
+				bcl->stats.accu_queue_sz += len;
+			}
+			bc = 1;
+		}
+		tipc_bclink_unlock(net);
+	}
+
+	if (unlikely(!bc))
+		__skb_queue_purge(list);
+
+	if (unlikely(rc)) {
+		kfree_skb(skb);
+		return rc;
+	}
+	/* Deliver message clone */
+	__skb_queue_head_init(&arrvq);
+	skb_queue_head_init(&inputq);
+	__skb_queue_tail(&arrvq, skb);
+	tipc_sk_mcast_rcv(net, &arrvq, &inputq);
+	return rc;
+}
+
+/**
+ * bclink_accept_pkt - accept an incoming, in-sequence broadcast packet
+ *
+ * Called with both sending node's lock and bclink_lock taken.
+ */
+static void bclink_accept_pkt(struct tipc_node *node, u32 seqno)
+{
+	struct tipc_net *tn = net_generic(node->net, tipc_net_id);
+
+	bclink_update_last_sent(node, seqno);
+	node->bclink.last_in = seqno;
+	node->bclink.oos_state = 0;
+	tn->bcl->stats.recv_info++;
+
+	/*
+	 * Unicast an ACK periodically, ensuring that
+	 * all nodes in the cluster don't ACK at the same time
+	 */
+	if (((seqno - tn->own_addr) % TIPC_MIN_LINK_WIN) == 0) {
+		tipc_link_proto_xmit(node->active_links[node->addr & 1],
+				     STATE_MSG, 0, 0, 0, 0);
+		tn->bcl->stats.sent_acks++;
+	}
+}
+
+/**
+ * tipc_bclink_rcv - receive a broadcast packet, and deliver upwards
+ *
+ * RCU is locked, no other locks set
+ */
+void tipc_bclink_rcv(struct net *net, struct sk_buff *buf)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_link *bcl = tn->bcl;
+	struct tipc_msg *msg = buf_msg(buf);
+	struct tipc_node *node;
+	u32 next_in;
+	u32 seqno;
+	int deferred = 0;
+	int pos = 0;
+	struct sk_buff *iskb;
+	struct sk_buff_head *arrvq, *inputq;
+
+	/* Screen out unwanted broadcast messages */
+	if (msg_mc_netid(msg) != tn->net_id)
+		goto exit;
+
+	node = tipc_node_find(net, msg_prevnode(msg));
+	if (unlikely(!node))
+		goto exit;
+
+	tipc_node_lock(node);
+	if (unlikely(!node->bclink.recv_permitted))
+		goto unlock;
+
+	/* Handle broadcast protocol message */
+	if (unlikely(msg_user(msg) == BCAST_PROTOCOL)) {
+		if (msg_type(msg) != STATE_MSG)
+			goto unlock;
+		if (msg_destnode(msg) == tn->own_addr) {
+			tipc_bclink_acknowledge(node, msg_bcast_ack(msg));
+			tipc_bclink_lock(net);
+			bcl->stats.recv_nacks++;
+			tn->bclink->retransmit_to = node;
+			bclink_retransmit_pkt(tn, msg_bcgap_after(msg),
+					      msg_bcgap_to(msg));
+			tipc_bclink_unlock(net);
+			tipc_node_unlock(node);
+		} else {
+			tipc_node_unlock(node);
+			bclink_peek_nack(net, msg);
+		}
+		tipc_node_put(node);
+		goto exit;
+	}
+
+	/* Handle in-sequence broadcast message */
+	seqno = msg_seqno(msg);
+	next_in = mod(node->bclink.last_in + 1);
+	arrvq = &tn->bclink->arrvq;
+	inputq = &tn->bclink->inputq;
+
+	if (likely(seqno == next_in)) {
+receive:
+		/* Deliver message to destination */
+		if (likely(msg_isdata(msg))) {
+			tipc_bclink_lock(net);
+			bclink_accept_pkt(node, seqno);
+			spin_lock_bh(&inputq->lock);
+			__skb_queue_tail(arrvq, buf);
+			spin_unlock_bh(&inputq->lock);
+			node->action_flags |= TIPC_BCAST_MSG_EVT;
+			tipc_bclink_unlock(net);
+			tipc_node_unlock(node);
+		} else if (msg_user(msg) == MSG_BUNDLER) {
+			tipc_bclink_lock(net);
+			bclink_accept_pkt(node, seqno);
+			bcl->stats.recv_bundles++;
+			bcl->stats.recv_bundled += msg_msgcnt(msg);
+			pos = 0;
+			while (tipc_msg_extract(buf, &iskb, &pos)) {
+				spin_lock_bh(&inputq->lock);
+				__skb_queue_tail(arrvq, iskb);
+				spin_unlock_bh(&inputq->lock);
+			}
+			node->action_flags |= TIPC_BCAST_MSG_EVT;
+			tipc_bclink_unlock(net);
+			tipc_node_unlock(node);
+		} else if (msg_user(msg) == MSG_FRAGMENTER) {
+			tipc_bclink_lock(net);
+			bclink_accept_pkt(node, seqno);
+			tipc_buf_append(&node->bclink.reasm_buf, &buf);
+			if (unlikely(!buf && !node->bclink.reasm_buf)) {
+				tipc_bclink_unlock(net);
+				goto unlock;
+			}
+			bcl->stats.recv_fragments++;
+			if (buf) {
+				bcl->stats.recv_fragmented++;
+				msg = buf_msg(buf);
+				tipc_bclink_unlock(net);
+				goto receive;
+			}
+			tipc_bclink_unlock(net);
+			tipc_node_unlock(node);
+		} else {
+			tipc_bclink_lock(net);
+			bclink_accept_pkt(node, seqno);
+			tipc_bclink_unlock(net);
+			tipc_node_unlock(node);
+			kfree_skb(buf);
+		}
+		buf = NULL;
+
+		/* Determine new synchronization state */
+		tipc_node_lock(node);
+		if (unlikely(!tipc_node_is_up(node)))
+			goto unlock;
+
+		if (node->bclink.last_in == node->bclink.last_sent)
+			goto unlock;
+
+		if (skb_queue_empty(&node->bclink.deferdq)) {
+			node->bclink.oos_state = 1;
+			goto unlock;
+		}
+
+		msg = buf_msg(skb_peek(&node->bclink.deferdq));
+		seqno = msg_seqno(msg);
+		next_in = mod(next_in + 1);
+		if (seqno != next_in)
+			goto unlock;
+
+		/* Take in-sequence message from deferred queue & deliver it */
+		buf = __skb_dequeue(&node->bclink.deferdq);
+		goto receive;
+	}
+
+	/* Handle out-of-sequence broadcast message */
+	if (less(next_in, seqno)) {
+		deferred = tipc_link_defer_pkt(&node->bclink.deferdq,
+					       buf);
+		bclink_update_last_sent(node, seqno);
+		buf = NULL;
+	}
+
+	tipc_bclink_lock(net);
+
+	if (deferred)
+		bcl->stats.deferred_recv++;
+	else
+		bcl->stats.duplicates++;
+
+	tipc_bclink_unlock(net);
+
+unlock:
+	tipc_node_unlock(node);
+	tipc_node_put(node);
+exit:
+	kfree_skb(buf);
+}
+
+u32 tipc_bclink_acks_missing(struct tipc_node *n_ptr)
+{
+	return (n_ptr->bclink.recv_permitted &&
+		(tipc_bclink_get_last_sent(n_ptr->net) != n_ptr->bclink.acked));
+}
+
+
+/**
+ * tipc_bcbearer_send - send a packet through the broadcast pseudo-bearer
+ *
+ * Send packet over as many bearers as necessary to reach all nodes
+ * that have joined the broadcast link.
+ *
+ * Returns 0 (packet sent successfully) under all circumstances,
+ * since the broadcast link's pseudo-bearer never blocks
+ */
+static int tipc_bcbearer_send(struct net *net, struct sk_buff *buf,
+			      struct tipc_bearer *unused1,
+			      struct tipc_media_addr *unused2)
+{
+	int bp_index;
+	struct tipc_msg *msg = buf_msg(buf);
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_bcbearer *bcbearer = tn->bcbearer;
+	struct tipc_bclink *bclink = tn->bclink;
+
+	/* Prepare broadcast link message for reliable transmission,
+	 * if first time trying to send it;
+	 * preparation is skipped for broadcast link protocol messages
+	 * since they are sent in an unreliable manner and don't need it
+	 */
+	if (likely(!msg_non_seq(buf_msg(buf)))) {
+		bcbuf_set_acks(buf, bclink->bcast_nodes.count);
+		msg_set_non_seq(msg, 1);
+		msg_set_mc_netid(msg, tn->net_id);
+		tn->bcl->stats.sent_info++;
+		if (WARN_ON(!bclink->bcast_nodes.count)) {
+			dump_stack();
+			return 0;
+		}
+	}
+
+	/* Send buffer over bearers until all targets reached */
+	bcbearer->remains = bclink->bcast_nodes;
+
+	for (bp_index = 0; bp_index < MAX_BEARERS; bp_index++) {
+		struct tipc_bearer *p = bcbearer->bpairs[bp_index].primary;
+		struct tipc_bearer *s = bcbearer->bpairs[bp_index].secondary;
+		struct tipc_bearer *bp[2] = {p, s};
+		struct tipc_bearer *b = bp[msg_link_selector(msg)];
+		struct sk_buff *tbuf;
+
+		if (!p)
+			break; /* No more bearers to try */
+		if (!b)
+			b = p;
+		tipc_nmap_diff(&bcbearer->remains, &b->nodes,
+			       &bcbearer->remains_new);
+		if (bcbearer->remains_new.count == bcbearer->remains.count)
+			continue; /* Nothing added by bearer pair */
+
+		if (bp_index == 0) {
+			/* Use original buffer for first bearer */
+			tipc_bearer_send(net, b->identity, buf, &b->bcast_addr);
+		} else {
+			/* Avoid concurrent buffer access */
+			tbuf = pskb_copy_for_clone(buf, GFP_ATOMIC);
+			if (!tbuf)
+				break;
+			tipc_bearer_send(net, b->identity, tbuf,
+					 &b->bcast_addr);
+			kfree_skb(tbuf); /* Bearer keeps a clone */
+		}
+		if (bcbearer->remains_new.count == 0)
+			break; /* All targets reached */
+
+		bcbearer->remains = bcbearer->remains_new;
+	}
+
+	return 0;
+}
+
+/**
+ * tipc_bcbearer_sort - create sets of bearer pairs used by broadcast bearer
+ */
+void tipc_bcbearer_sort(struct net *net, struct tipc_node_map *nm_ptr,
+			u32 node, bool action)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_bcbearer *bcbearer = tn->bcbearer;
+	struct tipc_bcbearer_pair *bp_temp = bcbearer->bpairs_temp;
+	struct tipc_bcbearer_pair *bp_curr;
+	struct tipc_bearer *b;
+	int b_index;
+	int pri;
+
+	tipc_bclink_lock(net);
+
+	if (action)
+		tipc_nmap_add(nm_ptr, node);
+	else
+		tipc_nmap_remove(nm_ptr, node);
+
+	/* Group bearers by priority (can assume max of two per priority) */
+	memset(bp_temp, 0, sizeof(bcbearer->bpairs_temp));
+
+	rcu_read_lock();
+	for (b_index = 0; b_index < MAX_BEARERS; b_index++) {
+		b = rcu_dereference_rtnl(tn->bearer_list[b_index]);
+		if (!b || !b->nodes.count)
+			continue;
+
+		if (!bp_temp[b->priority].primary)
+			bp_temp[b->priority].primary = b;
+		else
+			bp_temp[b->priority].secondary = b;
+	}
+	rcu_read_unlock();
+
+	/* Create array of bearer pairs for broadcasting */
+	bp_curr = bcbearer->bpairs;
+	memset(bcbearer->bpairs, 0, sizeof(bcbearer->bpairs));
+
+	for (pri = TIPC_MAX_LINK_PRI; pri >= 0; pri--) {
+
+		if (!bp_temp[pri].primary)
+			continue;
+
+		bp_curr->primary = bp_temp[pri].primary;
+
+		if (bp_temp[pri].secondary) {
+			if (tipc_nmap_equal(&bp_temp[pri].primary->nodes,
+					    &bp_temp[pri].secondary->nodes)) {
+				bp_curr->secondary = bp_temp[pri].secondary;
+			} else {
+				bp_curr++;
+				bp_curr->primary = bp_temp[pri].secondary;
+			}
+		}
+
+		bp_curr++;
+	}
+
+	tipc_bclink_unlock(net);
+}
+
+static int __tipc_nl_add_bc_link_stat(struct sk_buff *skb,
+				      struct tipc_stats *stats)
+{
+	int i;
+	struct nlattr *nest;
+
+	struct nla_map {
+		__u32 key;
+		__u32 val;
+	};
+
+	struct nla_map map[] = {
+		{TIPC_NLA_STATS_RX_INFO, stats->recv_info},
+		{TIPC_NLA_STATS_RX_FRAGMENTS, stats->recv_fragments},
+		{TIPC_NLA_STATS_RX_FRAGMENTED, stats->recv_fragmented},
+		{TIPC_NLA_STATS_RX_BUNDLES, stats->recv_bundles},
+		{TIPC_NLA_STATS_RX_BUNDLED, stats->recv_bundled},
+		{TIPC_NLA_STATS_TX_INFO, stats->sent_info},
+		{TIPC_NLA_STATS_TX_FRAGMENTS, stats->sent_fragments},
+		{TIPC_NLA_STATS_TX_FRAGMENTED, stats->sent_fragmented},
+		{TIPC_NLA_STATS_TX_BUNDLES, stats->sent_bundles},
+		{TIPC_NLA_STATS_TX_BUNDLED, stats->sent_bundled},
+		{TIPC_NLA_STATS_RX_NACKS, stats->recv_nacks},
+		{TIPC_NLA_STATS_RX_DEFERRED, stats->deferred_recv},
+		{TIPC_NLA_STATS_TX_NACKS, stats->sent_nacks},
+		{TIPC_NLA_STATS_TX_ACKS, stats->sent_acks},
+		{TIPC_NLA_STATS_RETRANSMITTED, stats->retransmitted},
+		{TIPC_NLA_STATS_DUPLICATES, stats->duplicates},
+		{TIPC_NLA_STATS_LINK_CONGS, stats->link_congs},
+		{TIPC_NLA_STATS_MAX_QUEUE, stats->max_queue_sz},
+		{TIPC_NLA_STATS_AVG_QUEUE, stats->queue_sz_counts ?
+			(stats->accu_queue_sz / stats->queue_sz_counts) : 0}
+	};
+
+	nest = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
+	if (!nest)
+		return -EMSGSIZE;
+
+	for (i = 0; i <  ARRAY_SIZE(map); i++)
+		if (nla_put_u32(skb, map[i].key, map[i].val))
+			goto msg_full;
+
+	nla_nest_end(skb, nest);
+
+	return 0;
+msg_full:
+	nla_nest_cancel(skb, nest);
+
+	return -EMSGSIZE;
+}
+
+int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg)
+{
+	int err;
+	void *hdr;
+	struct nlattr *attrs;
+	struct nlattr *prop;
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_link *bcl = tn->bcl;
+
+	if (!bcl)
+		return 0;
+
+	tipc_bclink_lock(net);
+
+	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
+			  NLM_F_MULTI, TIPC_NL_LINK_GET);
+	if (!hdr)
+		return -EMSGSIZE;
+
+	attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
+	if (!attrs)
+		goto msg_full;
+
+	/* The broadcast link is always up */
+	if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
+		goto attr_msg_full;
+
+	if (nla_put_flag(msg->skb, TIPC_NLA_LINK_BROADCAST))
+		goto attr_msg_full;
+	if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, bcl->name))
+		goto attr_msg_full;
+	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, bcl->next_in_no))
+		goto attr_msg_full;
+	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, bcl->next_out_no))
+		goto attr_msg_full;
+
+	prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
+	if (!prop)
+		goto attr_msg_full;
+	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bcl->window))
+		goto prop_msg_full;
+	nla_nest_end(msg->skb, prop);
+
+	err = __tipc_nl_add_bc_link_stat(msg->skb, &bcl->stats);
+	if (err)
+		goto attr_msg_full;
+
+	tipc_bclink_unlock(net);
+	nla_nest_end(msg->skb, attrs);
+	genlmsg_end(msg->skb, hdr);
+
+	return 0;
+
+prop_msg_full:
+	nla_nest_cancel(msg->skb, prop);
+attr_msg_full:
+	nla_nest_cancel(msg->skb, attrs);
+msg_full:
+	tipc_bclink_unlock(net);
+	genlmsg_cancel(msg->skb, hdr);
+
+	return -EMSGSIZE;
+}
+
+int tipc_bclink_reset_stats(struct net *net)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_link *bcl = tn->bcl;
+
+	if (!bcl)
+		return -ENOPROTOOPT;
+
+	tipc_bclink_lock(net);
+	memset(&bcl->stats, 0, sizeof(bcl->stats));
+	tipc_bclink_unlock(net);
+	return 0;
+}
+
+int tipc_bclink_set_queue_limits(struct net *net, u32 limit)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_link *bcl = tn->bcl;
+
+	if (!bcl)
+		return -ENOPROTOOPT;
+	if ((limit < TIPC_MIN_LINK_WIN) || (limit > TIPC_MAX_LINK_WIN))
+		return -EINVAL;
+
+	tipc_bclink_lock(net);
+	tipc_link_set_queue_limits(bcl, limit);
+	tipc_bclink_unlock(net);
+	return 0;
+}
+
+int tipc_bclink_init(struct net *net)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_bcbearer *bcbearer;
+	struct tipc_bclink *bclink;
+	struct tipc_link *bcl;
+
+	bcbearer = kzalloc(sizeof(*bcbearer), GFP_ATOMIC);
+	if (!bcbearer)
+		return -ENOMEM;
+
+	bclink = kzalloc(sizeof(*bclink), GFP_ATOMIC);
+	if (!bclink) {
+		kfree(bcbearer);
+		return -ENOMEM;
+	}
+
+	bcl = &bclink->link;
+	bcbearer->bearer.media = &bcbearer->media;
+	bcbearer->media.send_msg = tipc_bcbearer_send;
+	sprintf(bcbearer->media.name, "tipc-broadcast");
+
+	spin_lock_init(&bclink->lock);
+	__skb_queue_head_init(&bcl->transmq);
+	__skb_queue_head_init(&bcl->backlogq);
+	__skb_queue_head_init(&bcl->deferdq);
+	skb_queue_head_init(&bcl->wakeupq);
+	bcl->next_out_no = 1;
+	spin_lock_init(&bclink->node.lock);
+	__skb_queue_head_init(&bclink->arrvq);
+	skb_queue_head_init(&bclink->inputq);
+	bcl->owner = &bclink->node;
+	bcl->owner->net = net;
+	bcl->mtu = MAX_PKT_DEFAULT_MCAST;
+	tipc_link_set_queue_limits(bcl, BCLINK_WIN_DEFAULT);
+	bcl->bearer_id = MAX_BEARERS;
+	rcu_assign_pointer(tn->bearer_list[MAX_BEARERS], &bcbearer->bearer);
+	bcl->state = WORKING_WORKING;
+	bcl->pmsg = (struct tipc_msg *)&bcl->proto_msg;
+	msg_set_prevnode(bcl->pmsg, tn->own_addr);
+	strlcpy(bcl->name, tipc_bclink_name, TIPC_MAX_LINK_NAME);
+	tn->bcbearer = bcbearer;
+	tn->bclink = bclink;
+	tn->bcl = bcl;
+	return 0;
+}
+
+void tipc_bclink_stop(struct net *net)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+
+	tipc_bclink_lock(net);
+	tipc_link_purge_queues(tn->bcl);
+	tipc_bclink_unlock(net);
+
+	RCU_INIT_POINTER(tn->bearer_list[BCBEARER], NULL);
+	synchronize_net();
+	kfree(tn->bcbearer);
+	kfree(tn->bclink);
+}
+
+/**
+ * tipc_nmap_add - add a node to a node map
+ */
+static void tipc_nmap_add(struct tipc_node_map *nm_ptr, u32 node)
+{
+	int n = tipc_node(node);
+	int w = n / WSIZE;
+	u32 mask = (1 << (n % WSIZE));
+
+	if ((nm_ptr->map[w] & mask) == 0) {
+		nm_ptr->count++;
+		nm_ptr->map[w] |= mask;
+	}
+}
+
+/**
+ * tipc_nmap_remove - remove a node from a node map
+ */
+static void tipc_nmap_remove(struct tipc_node_map *nm_ptr, u32 node)
+{
+	int n = tipc_node(node);
+	int w = n / WSIZE;
+	u32 mask = (1 << (n % WSIZE));
+
+	if ((nm_ptr->map[w] & mask) != 0) {
+		nm_ptr->map[w] &= ~mask;
+		nm_ptr->count--;
+	}
+}
+
+/**
+ * tipc_nmap_diff - find differences between node maps
+ * @nm_a: input node map A
+ * @nm_b: input node map B
+ * @nm_diff: output node map A-B (i.e. nodes of A that are not in B)
+ */
+static void tipc_nmap_diff(struct tipc_node_map *nm_a,
+			   struct tipc_node_map *nm_b,
+			   struct tipc_node_map *nm_diff)
+{
+	int stop = ARRAY_SIZE(nm_a->map);
+	int w;
+	int b;
+	u32 map;
+
+	memset(nm_diff, 0, sizeof(*nm_diff));
+	for (w = 0; w < stop; w++) {
+		map = nm_a->map[w] ^ (nm_a->map[w] & nm_b->map[w]);
+		nm_diff->map[w] = map;
+		if (map != 0) {
+			for (b = 0 ; b < WSIZE; b++) {
+				if (map & (1 << b))
+					nm_diff->count++;
+			}
+		}
+	}
+}