Merge branch 'tipc-comm-groups'

Jon Maloy says:

====================
tipc: Introduce Communcation Group feature

With this commit series we introduce a 'Group Communication' feature in
order to resolve the datagram and multicast flow control problem. This
new feature makes it possible for a user to instantiate multiple private
virtual brokerless message buses by just creating and joining member
sockets.

The main features are as follows:
---------------------------------
- Sockets can join a group via a new setsockopt() call TIPC_GROUP_JOIN.
  If it is the first socket of the group this implies creation of the
  group. This call takes four parameters: 'type' serves as group
  identifier, 'instance' serves as member identifier, and 'scope'
  indicates the visibility of the group (node/cluster/zone). Finally,
  'flags' indicates different options for the socket joining the group.
  For the time being, there are only two such flags: 1) 'LOOPBACK'
  indicates if the creator of the socket wants to receive a copy of
  broadcast or multicast messages it sends to the group, 2) EVENTS
  indicates if it wants to receive membership (JOINED/LEFT) events for
  the other members of the group.

- Groups are closed, i.e., sockets which have not joined a group will
  not be able to send messages to or receive messages from members of
  the group, and vice versa. A socket can only be member of one group
  at a time.

- There are four transmission modes.
  1: Unicast. The sender transmits a message using the port identity
     (node:port tuple) of the receiving socket.
  2: Anycast. The sender transmits a message using a port name (type:
     instance:scope) of one of the receiving sockets. If more than
     one member socket matches the given address a destination is
     selected according to a round-robin algorithm, but also considering
     the destination load (advertised window size) as an additional
     criteria.
  3: Multicast. The sender transmits a message using a port name
     (type:instance:scope) of one or more of the receiving sockets.
     All sockets in the group matching the given address will receive
     a copy of the message.
  4: Broadcast. The sender transmits a message using the primtive
     send(). All members of the group, irrespective of their member
     identity (instance) number receive a copy of the message.

- TIPC broadcast is used for carrying messages in mode 3 or 4 when
  this is deemed more efficient, i.e., depending on number of actual
  destinations.

- All transmission modes are flow controlled, so that messages never
  are dropped or rejected, just like we are used to from connection
  oriented communication. A special algorithm guarantees that this is
  true even for multipoint-to-point communication, i.e., at occasions
  where many source sockets may decide to send simultaneously towards
  the same  destination socket.

- Sequence order is always guaranteed, even between the different
  transmission modes.

- Member join/leave events are received in all other member sockets
  in guaranteed order. I.e., a 'JOINED' (an empty message with the OOB
  bit set) will always be received before the first data message from
  a new member, and a 'LEAVE' (like 'JOINED', but with EOR bit set) will
  always arrive after the last data message from a leaving member.

-----
v2: Reordered variable declarations in descending length order, as per
    feedback from David Miller. This was done as far as permitted by the
    the initialization order.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/tipc.h

@@ -231,6 +231,21 @@ struct sockaddr_tipc {
 #define TIPC_SOCK_RECVQ_DEPTH	132	/* Default: none (read only) */
 #define TIPC_MCAST_BROADCAST    133     /* Default: TIPC selects. No arg */
 #define TIPC_MCAST_REPLICAST    134     /* Default: TIPC selects. No arg */
+#define TIPC_GROUP_JOIN         135     /* Takes struct tipc_group_req* */
+#define TIPC_GROUP_LEAVE        136     /* No argument */
+
+/*
+ * Flag values
+ */
+#define TIPC_GROUP_LOOPBACK     0x1  /* Receive copy of sent msg when match */
+#define TIPC_GROUP_MEMBER_EVTS  0x2  /* Receive membership events in socket */
+
+struct tipc_group_req {
+	__u32 type;      /* group id */
+	__u32 instance;  /* member id */
+	__u32 scope;     /* zone/cluster/node */
+	__u32 flags;
+};
 
 /*
  * Maximum sizes of TIPC bearer-related names (including terminating NULL)

net/tipc/Makefile

@@ -8,7 +8,7 @@ tipc-y	+= addr.o bcast.o bearer.o \
 	   core.o link.o discover.o msg.o  \
 	   name_distr.o  subscr.o monitor.o name_table.o net.o  \
 	   netlink.o netlink_compat.o node.o socket.o eth_media.o \
-	   server.o socket.o
+	   server.o socket.o group.o
 
 tipc-$(CONFIG_TIPC_MEDIA_UDP)	+= udp_media.o
 tipc-$(CONFIG_TIPC_MEDIA_IB)	+= ib_media.o

net/tipc/bcast.c

@@ -258,20 +258,20 @@ static int tipc_bcast_xmit(struct net *net, struct sk_buff_head *pkts,
 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;
-	struct u32_item *n, *tmp;
-	u32 dst, selector;
+	u32 dnode, selector;
 
 	selector = msg_link_selector(buf_msg(skb_peek(pkts)));
 	skb_queue_head_init(&_pkts);
 
-	list_for_each_entry_safe(n, tmp, &dests->list, list) {
-		dst = n->value;
-		if (!tipc_msg_pskb_copy(dst, pkts, &_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, dst, selector) == -ELINKCONG)
+		if (tipc_node_xmit(net, &_pkts, dnode, selector) == -ELINKCONG)
 			(*cong_link_cnt)++;
 	}
 	return 0;
@@ -554,7 +554,7 @@ void tipc_nlist_add(struct tipc_nlist *nl, u32 node)
 {
 	if (node == nl->self)
 		nl->local = true;
-	else if (u32_push(&nl->list, node))
+	else if (tipc_dest_push(&nl->list, node, 0))
 		nl->remote++;
 }
 
@@ -562,13 +562,13 @@ void tipc_nlist_del(struct tipc_nlist *nl, u32 node)
 {
 	if (node == nl->self)
 		nl->local = false;
-	else if (u32_del(&nl->list, node))
+	else if (tipc_dest_del(&nl->list, node, 0))
 		nl->remote--;
 }
 
 void tipc_nlist_purge(struct tipc_nlist *nl)
 {
-	u32_list_purge(&nl->list);
+	tipc_dest_list_purge(&nl->list);
 	nl->remote = 0;
 	nl->local = 0;
 }

net/tipc/core.h

@@ -132,6 +132,11 @@ static inline struct list_head *tipc_nodes(struct net *net)
 	return &tipc_net(net)->node_list;
 }
 
+static inline struct tipc_server *tipc_topsrv(struct net *net)
+{
+	return tipc_net(net)->topsrv;
+}
+
 static inline unsigned int tipc_hashfn(u32 addr)
 {
 	return addr & (NODE_HTABLE_SIZE - 1);

net/tipc/group.c

+/*
+ * net/tipc/group.c: TIPC group messaging code
+ *
+ * Copyright (c) 2017, Ericsson AB
+ * 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 "core.h"
+#include "addr.h"
+#include "group.h"
+#include "bcast.h"
+#include "server.h"
+#include "msg.h"
+#include "socket.h"
+#include "node.h"
+#include "name_table.h"
+#include "subscr.h"
+
+#define ADV_UNIT (((MAX_MSG_SIZE + MAX_H_SIZE) / FLOWCTL_BLK_SZ) + 1)
+#define ADV_IDLE ADV_UNIT
+#define ADV_ACTIVE (ADV_UNIT * 12)
+
+enum mbr_state {
+	MBR_QUARANTINED,
+	MBR_DISCOVERED,
+	MBR_JOINING,
+	MBR_PUBLISHED,
+	MBR_JOINED,
+	MBR_PENDING,
+	MBR_ACTIVE,
+	MBR_RECLAIMING,
+	MBR_REMITTED,
+	MBR_LEAVING
+};
+
+struct tipc_member {
+	struct rb_node tree_node;
+	struct list_head list;
+	struct list_head congested;
+	struct sk_buff *event_msg;
+	struct sk_buff_head deferredq;
+	struct tipc_group *group;
+	u32 node;
+	u32 port;
+	u32 instance;
+	enum mbr_state state;
+	u16 advertised;
+	u16 window;
+	u16 bc_rcv_nxt;
+	u16 bc_syncpt;
+	u16 bc_acked;
+	bool usr_pending;
+};
+
+struct tipc_group {
+	struct rb_root members;
+	struct list_head congested;
+	struct list_head pending;
+	struct list_head active;
+	struct list_head reclaiming;
+	struct tipc_nlist dests;
+	struct net *net;
+	int subid;
+	u32 type;
+	u32 instance;
+	u32 domain;
+	u32 scope;
+	u32 portid;
+	u16 member_cnt;
+	u16 active_cnt;
+	u16 max_active;
+	u16 bc_snd_nxt;
+	u16 bc_ackers;
+	bool loopback;
+	bool events;
+};
+
+static void tipc_group_proto_xmit(struct tipc_group *grp, struct tipc_member *m,
+				  int mtyp, struct sk_buff_head *xmitq);
+
+static void tipc_group_decr_active(struct tipc_group *grp,
+				   struct tipc_member *m)
+{
+	if (m->state == MBR_ACTIVE || m->state == MBR_RECLAIMING)
+		grp->active_cnt--;
+}
+
+static int tipc_group_rcvbuf_limit(struct tipc_group *grp)
+{
+	int max_active, active_pool, idle_pool;
+	int mcnt = grp->member_cnt + 1;
+
+	/* Limit simultaneous reception from other members */
+	max_active = min(mcnt / 8, 64);
+	max_active = max(max_active, 16);
+	grp->max_active = max_active;
+
+	/* Reserve blocks for active and idle members */
+	active_pool = max_active * ADV_ACTIVE;
+	idle_pool = (mcnt - max_active) * ADV_IDLE;
+
+	/* Scale to bytes, considering worst-case truesize/msgsize ratio */
+	return (active_pool + idle_pool) * FLOWCTL_BLK_SZ * 4;
+}
+
+u16 tipc_group_bc_snd_nxt(struct tipc_group *grp)
+{
+	return grp->bc_snd_nxt;
+}
+
+static bool tipc_group_is_enabled(struct tipc_member *m)
+{
+	return m->state != MBR_QUARANTINED && m->state != MBR_LEAVING;
+}
+
+static bool tipc_group_is_receiver(struct tipc_member *m)
+{
+	return m && m->state >= MBR_JOINED;
+}
+
+u32 tipc_group_exclude(struct tipc_group *grp)
+{
+	if (!grp->loopback)
+		return grp->portid;
+	return 0;
+}
+
+int tipc_group_size(struct tipc_group *grp)
+{
+	return grp->member_cnt;
+}
+
+struct tipc_group *tipc_group_create(struct net *net, u32 portid,
+				     struct tipc_group_req *mreq)
+{
+	struct tipc_group *grp;
+	u32 type = mreq->type;
+
+	grp = kzalloc(sizeof(*grp), GFP_ATOMIC);
+	if (!grp)
+		return NULL;
+	tipc_nlist_init(&grp->dests, tipc_own_addr(net));
+	INIT_LIST_HEAD(&grp->congested);
+	INIT_LIST_HEAD(&grp->active);
+	INIT_LIST_HEAD(&grp->pending);
+	INIT_LIST_HEAD(&grp->reclaiming);
+	grp->members = RB_ROOT;
+	grp->net = net;
+	grp->portid = portid;
+	grp->domain = addr_domain(net, mreq->scope);
+	grp->type = type;
+	grp->instance = mreq->instance;
+	grp->scope = mreq->scope;
+	grp->loopback = mreq->flags & TIPC_GROUP_LOOPBACK;
+	grp->events = mreq->flags & TIPC_GROUP_MEMBER_EVTS;
+	if (tipc_topsrv_kern_subscr(net, portid, type, 0, ~0, &grp->subid))
+		return grp;
+	kfree(grp);
+	return NULL;
+}
+
+void tipc_group_delete(struct net *net, struct tipc_group *grp)
+{
+	struct rb_root *tree = &grp->members;
+	struct tipc_member *m, *tmp;
+	struct sk_buff_head xmitq;
+
+	__skb_queue_head_init(&xmitq);
+
+	rbtree_postorder_for_each_entry_safe(m, tmp, tree, tree_node) {
+		tipc_group_proto_xmit(grp, m, GRP_LEAVE_MSG, &xmitq);
+		list_del(&m->list);
+		kfree(m);
+	}
+	tipc_node_distr_xmit(net, &xmitq);
+	tipc_nlist_purge(&grp->dests);
+	tipc_topsrv_kern_unsubscr(net, grp->subid);
+	kfree(grp);
+}
+
+struct tipc_member *tipc_group_find_member(struct tipc_group *grp,
+					   u32 node, u32 port)
+{
+	struct rb_node *n = grp->members.rb_node;
+	u64 nkey, key = (u64)node << 32 | port;
+	struct tipc_member *m;
+
+	while (n) {
+		m = container_of(n, struct tipc_member, tree_node);
+		nkey = (u64)m->node << 32 | m->port;
+		if (key < nkey)
+			n = n->rb_left;
+		else if (key > nkey)
+			n = n->rb_right;
+		else
+			return m;
+	}
+	return NULL;
+}
+
+static struct tipc_member *tipc_group_find_dest(struct tipc_group *grp,
+						u32 node, u32 port)
+{
+	struct tipc_member *m;
+
+	m = tipc_group_find_member(grp, node, port);
+	if (m && tipc_group_is_enabled(m))
+		return m;
+	return NULL;
+}
+
+static struct tipc_member *tipc_group_find_node(struct tipc_group *grp,
+						u32 node)
+{
+	struct tipc_member *m;
+	struct rb_node *n;
+
+	for (n = rb_first(&grp->members); n; n = rb_next(n)) {
+		m = container_of(n, struct tipc_member, tree_node);
+		if (m->node == node)
+			return m;
+	}
+	return NULL;
+}
+
+static void tipc_group_add_to_tree(struct tipc_group *grp,
+				   struct tipc_member *m)
+{
+	u64 nkey, key = (u64)m->node << 32 | m->port;
+	struct rb_node **n, *parent = NULL;
+	struct tipc_member *tmp;
+
+	n = &grp->members.rb_node;
+	while (*n) {
+		tmp = container_of(*n, struct tipc_member, tree_node);
+		parent = *n;
+		tmp = container_of(parent, struct tipc_member, tree_node);
+		nkey = (u64)tmp->node << 32 | tmp->port;
+		if (key < nkey)
+			n = &(*n)->rb_left;
+		else if (key > nkey)
+			n = &(*n)->rb_right;
+		else
+			return;
+	}
+	rb_link_node(&m->tree_node, parent, n);
+	rb_insert_color(&m->tree_node, &grp->members);
+}
+
+static struct tipc_member *tipc_group_create_member(struct tipc_group *grp,
+						    u32 node, u32 port,
+						    int state)
+{
+	struct tipc_member *m;
+
+	m = kzalloc(sizeof(*m), GFP_ATOMIC);
+	if (!m)
+		return NULL;
+	INIT_LIST_HEAD(&m->list);
+	INIT_LIST_HEAD(&m->congested);
+	__skb_queue_head_init(&m->deferredq);
+	m->group = grp;
+	m->node = node;
+	m->port = port;
+	m->bc_acked = grp->bc_snd_nxt - 1;
+	grp->member_cnt++;
+	tipc_group_add_to_tree(grp, m);
+	tipc_nlist_add(&grp->dests, m->node);
+	m->state = state;
+	return m;
+}
+
+void tipc_group_add_member(struct tipc_group *grp, u32 node, u32 port)
+{
+	tipc_group_create_member(grp, node, port, MBR_DISCOVERED);
+}
+
+static void tipc_group_delete_member(struct tipc_group *grp,
+				     struct tipc_member *m)
+{
+	rb_erase(&m->tree_node, &grp->members);
+	grp->member_cnt--;
+
+	/* Check if we were waiting for replicast ack from this member */
+	if (grp->bc_ackers && less(m->bc_acked, grp->bc_snd_nxt - 1))
+		grp->bc_ackers--;
+
+	list_del_init(&m->list);
+	list_del_init(&m->congested);
+	tipc_group_decr_active(grp, m);
+
+	/* If last member on a node, remove node from dest list */
+	if (!tipc_group_find_node(grp, m->node))
+		tipc_nlist_del(&grp->dests, m->node);
+
+	kfree(m);
+}
+
+struct tipc_nlist *tipc_group_dests(struct tipc_group *grp)
+{
+	return &grp->dests;
+}
+
+void tipc_group_self(struct tipc_group *grp, struct tipc_name_seq *seq,
+		     int *scope)
+{
+	seq->type = grp->type;
+	seq->lower = grp->instance;
+	seq->upper = grp->instance;
+	*scope = grp->scope;
+}
+
+void tipc_group_update_member(struct tipc_member *m, int len)
+{
+	struct tipc_group *grp = m->group;
+	struct tipc_member *_m, *tmp;
+
+	if (!tipc_group_is_enabled(m))
+		return;
+
+	m->window -= len;
+
+	if (m->window >= ADV_IDLE)
+		return;
+
+	if (!list_empty(&m->congested))
+		return;
+
+	/* Sort member into congested members' list */
+	list_for_each_entry_safe(_m, tmp, &grp->congested, congested) {
+		if (m->window > _m->window)
+			continue;
+		list_add_tail(&m->congested, &_m->congested);
+		return;
+	}
+	list_add_tail(&m->congested, &grp->congested);
+}
+
+void tipc_group_update_bc_members(struct tipc_group *grp, int len, bool ack)
+{
+	u16 prev = grp->bc_snd_nxt - 1;
+	struct tipc_member *m;
+	struct rb_node *n;
+
+	for (n = rb_first(&grp->members); n; n = rb_next(n)) {
+		m = container_of(n, struct tipc_member, tree_node);
+		if (tipc_group_is_enabled(m)) {
+			tipc_group_update_member(m, len);
+			m->bc_acked = prev;
+		}
+	}
+
+	/* Mark number of acknowledges to expect, if any */
+	if (ack)
+		grp->bc_ackers = grp->member_cnt;
+	grp->bc_snd_nxt++;
+}
+
+bool tipc_group_cong(struct tipc_group *grp, u32 dnode, u32 dport,
+		     int len, struct tipc_member **mbr)
+{
+	struct sk_buff_head xmitq;
+	struct tipc_member *m;
+	int adv, state;
+
+	m = tipc_group_find_dest(grp, dnode, dport);
+	*mbr = m;
+	if (!m)
+		return false;
+	if (m->usr_pending)
+		return true;
+	if (m->window >= len)
+		return false;
+	m->usr_pending = true;
+
+	/* If not fully advertised, do it now to prevent mutual blocking */
+	adv = m->advertised;
+	state = m->state;
+	if (state < MBR_JOINED)
+		return true;
+	if (state == MBR_JOINED && adv == ADV_IDLE)
+		return true;
+	if (state == MBR_ACTIVE && adv == ADV_ACTIVE)
+		return true;
+	if (state == MBR_PENDING && adv == ADV_IDLE)
+		return true;
+	skb_queue_head_init(&xmitq);
+	tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, &xmitq);
+	tipc_node_distr_xmit(grp->net, &xmitq);
+	return true;
+}
+
+bool tipc_group_bc_cong(struct tipc_group *grp, int len)
+{
+	struct tipc_member *m = NULL;
+
+	/* If prev bcast was replicast, reject until all receivers have acked */
+	if (grp->bc_ackers)
+		return true;
+
+	if (list_empty(&grp->congested))
+		return false;
+
+	m = list_first_entry(&grp->congested, struct tipc_member, congested);
+	if (m->window >= len)
+		return false;
+
+	return tipc_group_cong(grp, m->node, m->port, len, &m);
+}
+
+/* tipc_group_sort_msg() - sort msg into queue by bcast sequence number
+ */
+static void tipc_group_sort_msg(struct sk_buff *skb, struct sk_buff_head *defq)
+{
+	struct tipc_msg *_hdr, *hdr = buf_msg(skb);
+	u16 bc_seqno = msg_grp_bc_seqno(hdr);
+	struct sk_buff *_skb, *tmp;
+	int mtyp = msg_type(hdr);
+
+	/* Bcast/mcast may be bypassed by ucast or other bcast, - sort it in */
+	if (mtyp == TIPC_GRP_BCAST_MSG || mtyp == TIPC_GRP_MCAST_MSG) {
+		skb_queue_walk_safe(defq, _skb, tmp) {
+			_hdr = buf_msg(_skb);
+			if (!less(bc_seqno, msg_grp_bc_seqno(_hdr)))
+				continue;
+			__skb_queue_before(defq, _skb, skb);
+			return;
+		}
+		/* Bcast was not bypassed, - add to tail */
+	}
+	/* Unicasts are never bypassed, - always add to tail */
+	__skb_queue_tail(defq, skb);
+}
+
+/* tipc_group_filter_msg() - determine if we should accept arriving message
+ */
+void tipc_group_filter_msg(struct tipc_group *grp, struct sk_buff_head *inputq,
+			   struct sk_buff_head *xmitq)
+{
+	struct sk_buff *skb = __skb_dequeue(inputq);
+	bool ack, deliver, update, leave = false;
+	struct sk_buff_head *defq;
+	struct tipc_member *m;
+	struct tipc_msg *hdr;
+	u32 node, port;
+	int mtyp, blks;
+
+	if (!skb)
+		return;
+
+	hdr = buf_msg(skb);
+	node =  msg_orignode(hdr);
+	port = msg_origport(hdr);
+
+	if (!msg_in_group(hdr))
+		goto drop;
+
+	m = tipc_group_find_member(grp, node, port);
+	if (!tipc_group_is_receiver(m))
+		goto drop;
+
+	if (less(msg_grp_bc_seqno(hdr), m->bc_rcv_nxt))
+		goto drop;
+
+	TIPC_SKB_CB(skb)->orig_member = m->instance;
+	defq = &m->deferredq;
+	tipc_group_sort_msg(skb, defq);
+
+	while ((skb = skb_peek(defq))) {
+		hdr = buf_msg(skb);
+		mtyp = msg_type(hdr);
+		deliver = true;
+		ack = false;
+		update = false;
+
+		if (more(msg_grp_bc_seqno(hdr), m->bc_rcv_nxt))
+			break;
+
+		/* Decide what to do with message */
+		switch (mtyp) {
+		case TIPC_GRP_MCAST_MSG:
+			if (msg_nameinst(hdr) != grp->instance) {
+				update = true;
+				deliver = false;
+			}
+			/* Fall thru */
+		case TIPC_GRP_BCAST_MSG:
+			m->bc_rcv_nxt++;
+			ack = msg_grp_bc_ack_req(hdr);
+			break;
+		case TIPC_GRP_UCAST_MSG:
+			break;
+		case TIPC_GRP_MEMBER_EVT:
+			if (m->state == MBR_LEAVING)
+				leave = true;
+			if (!grp->events)
+				deliver = false;
+			break;
+		default:
+			break;
+		}
+
+		/* Execute decisions */
+		__skb_dequeue(defq);
+		if (deliver)
+			__skb_queue_tail(inputq, skb);
+		else
+			kfree_skb(skb);
+
+		if (ack)
+			tipc_group_proto_xmit(grp, m, GRP_ACK_MSG, xmitq);
+
+		if (leave) {
+			tipc_group_delete_member(grp, m);
+			__skb_queue_purge(defq);
+			break;
+		}
+		if (!update)
+			continue;
+
+		blks = msg_blocks(hdr);
+		tipc_group_update_rcv_win(grp, blks, node, port, xmitq);
+	}
+	return;
+drop:
+	kfree_skb(skb);
+}
+
+void tipc_group_update_rcv_win(struct tipc_group *grp, int blks, u32 node,
+			       u32 port, struct sk_buff_head *xmitq)
+{
+	struct list_head *active = &grp->active;
+	int max_active = grp->max_active;
+	int reclaim_limit = max_active * 3 / 4;
+	int active_cnt = grp->active_cnt;
+	struct tipc_member *m, *rm;
+
+	m = tipc_group_find_member(grp, node, port);
+	if (!m)
+		return;
+
+	m->advertised -= blks;
+
+	switch (m->state) {
+	case MBR_JOINED:
+		/* Reclaim advertised space from least active member */
+		if (!list_empty(active) && active_cnt >= reclaim_limit) {
+			rm = list_first_entry(active, struct tipc_member, list);
+			rm->state = MBR_RECLAIMING;
+			list_move_tail(&rm->list, &grp->reclaiming);
+			tipc_group_proto_xmit(grp, rm, GRP_RECLAIM_MSG, xmitq);
+		}
+		/* If max active, become pending and wait for reclaimed space */
+		if (active_cnt >= max_active) {
+			m->state = MBR_PENDING;
+			list_add_tail(&m->list, &grp->pending);
+			break;
+		}
+		/* Otherwise become active */
+		m->state = MBR_ACTIVE;
+		list_add_tail(&m->list, &grp->active);
+		grp->active_cnt++;
+		/* Fall through */
+	case MBR_ACTIVE:
+		if (!list_is_last(&m->list, &grp->active))
+			list_move_tail(&m->list, &grp->active);
+		if (m->advertised > (ADV_ACTIVE * 3 / 4))
+			break;
+		tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, xmitq);
+		break;
+	case MBR_REMITTED:
+		if (m->advertised > ADV_IDLE)
+			break;
+		m->state = MBR_JOINED;
+		if (m->advertised < ADV_IDLE) {
+			pr_warn_ratelimited("Rcv unexpected msg after REMIT\n");
+			tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, xmitq);
+		}
+		break;
+	case MBR_RECLAIMING:
+	case MBR_DISCOVERED:
+	case MBR_JOINING:
+	case MBR_LEAVING:
+	default:
+		break;
+	}
+}
+
+static void tipc_group_proto_xmit(struct tipc_group *grp, struct tipc_member *m,
+				  int mtyp, struct sk_buff_head *xmitq)
+{
+	struct tipc_msg *hdr;
+	struct sk_buff *skb;
+	int adv = 0;
+
+	skb = tipc_msg_create(GROUP_PROTOCOL, mtyp, INT_H_SIZE, 0,
+			      m->node, tipc_own_addr(grp->net),
+			      m->port, grp->portid, 0);
+	if (!skb)
+		return;
+
+	if (m->state == MBR_ACTIVE)
+		adv = ADV_ACTIVE - m->advertised;
+	else if (m->state == MBR_JOINED || m->state == MBR_PENDING)
+		adv = ADV_IDLE - m->advertised;
+
+	hdr = buf_msg(skb);
+
+	if (mtyp == GRP_JOIN_MSG) {
+		msg_set_grp_bc_syncpt(hdr, grp->bc_snd_nxt);
+		msg_set_adv_win(hdr, adv);
+		m->advertised += adv;
+	} else if (mtyp == GRP_LEAVE_MSG) {
+		msg_set_grp_bc_syncpt(hdr, grp->bc_snd_nxt);
+	} else if (mtyp == GRP_ADV_MSG) {
+		msg_set_adv_win(hdr, adv);
+		m->advertised += adv;
+	} else if (mtyp == GRP_ACK_MSG) {
+		msg_set_grp_bc_acked(hdr, m->bc_rcv_nxt);
+	} else if (mtyp == GRP_REMIT_MSG) {
+		msg_set_grp_remitted(hdr, m->window);
+	}
+	__skb_queue_tail(xmitq, skb);
+}
+
+void tipc_group_proto_rcv(struct tipc_group *grp, bool *usr_wakeup,
+			  struct tipc_msg *hdr, struct sk_buff_head *inputq,
+			  struct sk_buff_head *xmitq)
+{
+	u32 node = msg_orignode(hdr);
+	u32 port = msg_origport(hdr);
+	struct tipc_member *m, *pm;
+	struct tipc_msg *ehdr;
+	u16 remitted, in_flight;
+
+	if (!grp)
+		return;
+
+	m = tipc_group_find_member(grp, node, port);
+
+	switch (msg_type(hdr)) {
+	case GRP_JOIN_MSG:
+		if (!m)
+			m = tipc_group_create_member(grp, node, port,
+						     MBR_QUARANTINED);
+		if (!m)
+			return;
+		m->bc_syncpt = msg_grp_bc_syncpt(hdr);
+		m->bc_rcv_nxt = m->bc_syncpt;
+		m->window += msg_adv_win(hdr);
+
+		/* Wait until PUBLISH event is received */
+		if (m->state == MBR_DISCOVERED) {
+			m->state = MBR_JOINING;
+		} else if (m->state == MBR_PUBLISHED) {
+			m->state = MBR_JOINED;
+			*usr_wakeup = true;
+			m->usr_pending = false;
+			tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, xmitq);
+			ehdr = buf_msg(m->event_msg);
+			msg_set_grp_bc_seqno(ehdr, m->bc_syncpt);
+			__skb_queue_tail(inputq, m->event_msg);
+		}
+		if (m->window < ADV_IDLE)
+			tipc_group_update_member(m, 0);
+		else
+			list_del_init(&m->congested);
+		return;
+	case GRP_LEAVE_MSG:
+		if (!m)
+			return;
+		m->bc_syncpt = msg_grp_bc_syncpt(hdr);
+
+		/* Wait until WITHDRAW event is received */
+		if (m->state != MBR_LEAVING) {
+			tipc_group_decr_active(grp, m);
+			m->state = MBR_LEAVING;
+			return;
+		}
+		/* Otherwise deliver already received WITHDRAW event */
+		ehdr = buf_msg(m->event_msg);
+		msg_set_grp_bc_seqno(ehdr, m->bc_syncpt);
+		__skb_queue_tail(inputq, m->event_msg);
+		*usr_wakeup = true;
+		list_del_init(&m->congested);
+		return;
+	case GRP_ADV_MSG:
+		if (!m)
+			return;
+		m->window += msg_adv_win(hdr);
+		*usr_wakeup = m->usr_pending;
+		m->usr_pending = false;
+		list_del_init(&m->congested);
+		return;
+	case GRP_ACK_MSG:
+		if (!m)
+			return;
+		m->bc_acked = msg_grp_bc_acked(hdr);
+		if (--grp->bc_ackers)
+			break;
+		*usr_wakeup = true;
+		m->usr_pending = false;
+		return;
+	case GRP_RECLAIM_MSG:
+		if (!m)
+			return;
+		*usr_wakeup = m->usr_pending;
+		m->usr_pending = false;
+		tipc_group_proto_xmit(grp, m, GRP_REMIT_MSG, xmitq);
+		m->window = ADV_IDLE;
+		return;
+	case GRP_REMIT_MSG:
+		if (!m || m->state != MBR_RECLAIMING)
+			return;
+
+		list_del_init(&m->list);
+		grp->active_cnt--;
+		remitted = msg_grp_remitted(hdr);
+
+		/* Messages preceding the REMIT still in receive queue */
+		if (m->advertised > remitted) {
+			m->state = MBR_REMITTED;
+			in_flight = m->advertised - remitted;
+		}
+		/* All messages preceding the REMIT have been read */
+		if (m->advertised <= remitted) {
+			m->state = MBR_JOINED;
+			in_flight = 0;
+		}
+		/* ..and the REMIT overtaken by more messages => re-advertise */
+		if (m->advertised < remitted)
+			tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, xmitq);
+
+		m->advertised = ADV_IDLE + in_flight;
+
+		/* Set oldest pending member to active and advertise */
+		if (list_empty(&grp->pending))
+			return;
+		pm = list_first_entry(&grp->pending, struct tipc_member, list);
+		pm->state = MBR_ACTIVE;
+		list_move_tail(&pm->list, &grp->active);
+		grp->active_cnt++;
+		if (pm->advertised <= (ADV_ACTIVE * 3 / 4))
+			tipc_group_proto_xmit(grp, pm, GRP_ADV_MSG, xmitq);
+		return;
+	default:
+		pr_warn("Received unknown GROUP_PROTO message\n");
+	}
+}
+
+/* tipc_group_member_evt() - receive and handle a member up/down event
+ */
+void tipc_group_member_evt(struct tipc_group *grp,
+			   bool *usr_wakeup,
+			   int *sk_rcvbuf,
+			   struct sk_buff *skb,
+			   struct sk_buff_head *inputq,
+			   struct sk_buff_head *xmitq)
+{
+	struct tipc_msg *hdr = buf_msg(skb);
+	struct tipc_event *evt = (void *)msg_data(hdr);
+	u32 instance = evt->found_lower;
+	u32 node = evt->port.node;
+	u32 port = evt->port.ref;
+	int event = evt->event;
+	struct tipc_member *m;
+	struct net *net;
+	bool node_up;
+	u32 self;
+
+	if (!grp)
+		goto drop;
+
+	net = grp->net;
+	self = tipc_own_addr(net);
+	if (!grp->loopback && node == self && port == grp->portid)
+		goto drop;
+
+	/* Convert message before delivery to user */
+	msg_set_hdr_sz(hdr, GROUP_H_SIZE);
+	msg_set_user(hdr, TIPC_CRITICAL_IMPORTANCE);
+	msg_set_type(hdr, TIPC_GRP_MEMBER_EVT);
+	msg_set_origport(hdr, port);
+	msg_set_orignode(hdr, node);
+	msg_set_nametype(hdr, grp->type);
+	msg_set_grp_evt(hdr, event);
+
+	m = tipc_group_find_member(grp, node, port);
+
+	if (event == TIPC_PUBLISHED) {
+		if (!m)
+			m = tipc_group_create_member(grp, node, port,
+						     MBR_DISCOVERED);
+		if (!m)
+			goto drop;
+
+		/* Hold back event if JOIN message not yet received */
+		if (m->state == MBR_DISCOVERED) {
+			m->event_msg = skb;
+			m->state = MBR_PUBLISHED;
+		} else {
+			msg_set_grp_bc_seqno(hdr, m->bc_syncpt);
+			__skb_queue_tail(inputq, skb);
+			m->state = MBR_JOINED;
+			*usr_wakeup = true;
+			m->usr_pending = false;
+		}
+		m->instance = instance;
+		TIPC_SKB_CB(skb)->orig_member = m->instance;
+		tipc_group_proto_xmit(grp, m, GRP_JOIN_MSG, xmitq);
+		if (m->window < ADV_IDLE)
+			tipc_group_update_member(m, 0);
+		else
+			list_del_init(&m->congested);
+	} else if (event == TIPC_WITHDRAWN) {
+		if (!m)
+			goto drop;
+
+		TIPC_SKB_CB(skb)->orig_member = m->instance;
+
+		*usr_wakeup = true;
+		m->usr_pending = false;
+		node_up = tipc_node_is_up(net, node);
+
+		/* Hold back event if more messages might be expected */
+		if (m->state != MBR_LEAVING && node_up) {
+			m->event_msg = skb;
+			tipc_group_decr_active(grp, m);
+			m->state = MBR_LEAVING;
+		} else {
+			if (node_up)
+				msg_set_grp_bc_seqno(hdr, m->bc_syncpt);
+			else
+				msg_set_grp_bc_seqno(hdr, m->bc_rcv_nxt);
+			__skb_queue_tail(inputq, skb);
+		}
+		list_del_init(&m->congested);
+	}
+	*sk_rcvbuf = tipc_group_rcvbuf_limit(grp);
+	return;
+drop:
+	kfree_skb(skb);
+}

net/tipc/group.h

+/*
+ * net/tipc/group.h: Include file for TIPC group unicast/multicast functions
+ *
+ * Copyright (c) 2017, Ericsson AB
+ * 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.
+ */
+
+#ifndef _TIPC_GROUP_H
+#define _TIPC_GROUP_H
+
+#include "core.h"
+
+struct tipc_group;
+struct tipc_member;
+struct tipc_msg;
+
+struct tipc_group *tipc_group_create(struct net *net, u32 portid,
+				     struct tipc_group_req *mreq);
+void tipc_group_delete(struct net *net, struct tipc_group *grp);
+void tipc_group_add_member(struct tipc_group *grp, u32 node, u32 port);
+struct tipc_nlist *tipc_group_dests(struct tipc_group *grp);
+void tipc_group_self(struct tipc_group *grp, struct tipc_name_seq *seq,
+		     int *scope);
+u32 tipc_group_exclude(struct tipc_group *grp);
+void tipc_group_filter_msg(struct tipc_group *grp,
+			   struct sk_buff_head *inputq,
+			   struct sk_buff_head *xmitq);
+void tipc_group_member_evt(struct tipc_group *grp, bool *wakeup,
+			   int *sk_rcvbuf, struct sk_buff *skb,
+			   struct sk_buff_head *inputq,
+			   struct sk_buff_head *xmitq);
+void tipc_group_proto_rcv(struct tipc_group *grp, bool *wakeup,
+			  struct tipc_msg *hdr,
+			  struct sk_buff_head *inputq,
+			  struct sk_buff_head *xmitq);
+void tipc_group_update_bc_members(struct tipc_group *grp, int len, bool ack);
+bool tipc_group_cong(struct tipc_group *grp, u32 dnode, u32 dport,
+		     int len, struct tipc_member **m);
+bool tipc_group_bc_cong(struct tipc_group *grp, int len);
+void tipc_group_update_rcv_win(struct tipc_group *grp, int blks, u32 node,
+			       u32 port, struct sk_buff_head *xmitq);
+u16 tipc_group_bc_snd_nxt(struct tipc_group *grp);
+void tipc_group_update_member(struct tipc_member *m, int len);
+int tipc_group_size(struct tipc_group *grp);
+#endif

net/tipc/link.c

@@ -1039,6 +1039,7 @@ int tipc_link_retrans(struct tipc_link *l, struct tipc_link *nacker,
 static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb,
 			    struct sk_buff_head *inputq)
 {
+	struct sk_buff_head *mc_inputq = l->bc_rcvlink->inputq;
 	struct tipc_msg *hdr = buf_msg(skb);
 
 	switch (msg_user(hdr)) {
@@ -1046,12 +1047,14 @@ static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb,
 	case TIPC_MEDIUM_IMPORTANCE:
 	case TIPC_HIGH_IMPORTANCE:
 	case TIPC_CRITICAL_IMPORTANCE:
-		if (unlikely(msg_type(hdr) == TIPC_MCAST_MSG)) {
-			skb_queue_tail(l->bc_rcvlink->inputq, skb);
+		if (unlikely(msg_in_group(hdr) || msg_mcast(hdr))) {
+			skb_queue_tail(mc_inputq, skb);
 			return true;
 		}
 	case CONN_MANAGER:
-		skb_queue_tail(inputq, skb);
+		return true;
+	case GROUP_PROTOCOL:
+		skb_queue_tail(mc_inputq, skb);
 		return true;
 	case NAME_DISTRIBUTOR:
 		l->bc_rcvlink->state = LINK_ESTABLISHED;

net/tipc/msg.c

@@ -666,3 +666,10 @@ void __tipc_skb_queue_sorted(struct sk_buff_head *list, u16 seqno,
 	}
 	kfree_skb(skb);
 }
+
+void tipc_skb_reject(struct net *net, int err, struct sk_buff *skb,
+		     struct sk_buff_head *xmitq)
+{
+	if (tipc_msg_reverse(tipc_own_addr(net), &skb, err))
+		__skb_queue_tail(xmitq, skb);
+}

net/tipc/msg.h

 /*
  * net/tipc/msg.h: Include file for TIPC message header routines
  *
- * Copyright (c) 2000-2007, 2014-2015 Ericsson AB
+ * Copyright (c) 2000-2007, 2014-2017 Ericsson AB
  * Copyright (c) 2005-2008, 2010-2011, Wind River Systems
  * All rights reserved.
  *
@@ -65,6 +65,10 @@ struct plist;
 #define TIPC_MCAST_MSG          1
 #define TIPC_NAMED_MSG          2
 #define TIPC_DIRECT_MSG         3
+#define TIPC_GRP_MEMBER_EVT     4
+#define TIPC_GRP_BCAST_MSG      5
+#define TIPC_GRP_MCAST_MSG      6
+#define TIPC_GRP_UCAST_MSG      7
 
 /*
  * Internal message users
@@ -73,11 +77,13 @@ struct plist;
 #define  MSG_BUNDLER          6
 #define  LINK_PROTOCOL        7
 #define  CONN_MANAGER         8
+#define  GROUP_PROTOCOL       9
 #define  TUNNEL_PROTOCOL      10
 #define  NAME_DISTRIBUTOR     11
 #define  MSG_FRAGMENTER       12
 #define  LINK_CONFIG          13
 #define  SOCK_WAKEUP          14       /* pseudo user */
+#define  TOP_SRV              15       /* pseudo user */
 
 /*
  * Message header sizes
@@ -86,6 +92,7 @@ struct plist;
 #define BASIC_H_SIZE              32	/* Basic payload message */
 #define NAMED_H_SIZE              40	/* Named payload message */
 #define MCAST_H_SIZE              44	/* Multicast payload message */
+#define GROUP_H_SIZE              44	/* Group payload message */
 #define INT_H_SIZE                40	/* Internal messages */
 #define MIN_H_SIZE                24	/* Smallest legal TIPC header size */
 #define MAX_H_SIZE                60	/* Largest possible TIPC header size */
@@ -96,6 +103,7 @@ struct plist;
 
 struct tipc_skb_cb {
 	u32 bytes_read;
+	u32 orig_member;
 	struct sk_buff *tail;
 	bool validated;
 	u16 chain_imp;
@@ -188,6 +196,11 @@ static inline u32 msg_size(struct tipc_msg *m)
 	return msg_bits(m, 0, 0, 0x1ffff);
 }
 
+static inline u32 msg_blocks(struct tipc_msg *m)
+{
+	return (msg_size(m) / 1024) + 1;
+}
+
 static inline u32 msg_data_sz(struct tipc_msg *m)
 {
 	return msg_size(m) - msg_hdr_sz(m);
@@ -251,6 +264,18 @@ static inline void msg_set_type(struct tipc_msg *m, u32 n)
 	msg_set_bits(m, 1, 29, 0x7, n);
 }
 
+static inline int msg_in_group(struct tipc_msg *m)
+{
+	int mtyp = msg_type(m);
+
+	return mtyp >= TIPC_GRP_MEMBER_EVT && mtyp <= TIPC_GRP_UCAST_MSG;
+}
+
+static inline bool msg_is_grp_evt(struct tipc_msg *m)
+{
+	return msg_type(m) == TIPC_GRP_MEMBER_EVT;
+}
+
 static inline u32 msg_named(struct tipc_msg *m)
 {
 	return msg_type(m) == TIPC_NAMED_MSG;
@@ -258,7 +283,10 @@ static inline u32 msg_named(struct tipc_msg *m)
 
 static inline u32 msg_mcast(struct tipc_msg *m)
 {
-	return msg_type(m) == TIPC_MCAST_MSG;
+	int mtyp = msg_type(m);
+
+	return ((mtyp == TIPC_MCAST_MSG) || (mtyp == TIPC_GRP_BCAST_MSG) ||
+		(mtyp == TIPC_GRP_MCAST_MSG));
 }
 
 static inline u32 msg_connected(struct tipc_msg *m)
@@ -513,6 +541,16 @@ static inline void msg_set_nameupper(struct tipc_msg *m, u32 n)
 #define DSC_REQ_MSG		0
 #define DSC_RESP_MSG		1
 
+/*
+ * Group protocol message types
+ */
+#define GRP_JOIN_MSG         0
+#define GRP_LEAVE_MSG        1
+#define GRP_ADV_MSG          2
+#define GRP_ACK_MSG          3
+#define GRP_RECLAIM_MSG      4
+#define GRP_REMIT_MSG        5
+
 /*
  * Word 1
  */
@@ -764,12 +802,12 @@ static inline void msg_set_conn_ack(struct tipc_msg *m, u32 n)
 	msg_set_bits(m, 9, 16, 0xffff, n);
 }
 
-static inline u32 msg_adv_win(struct tipc_msg *m)
+static inline u16 msg_adv_win(struct tipc_msg *m)
 {
 	return msg_bits(m, 9, 0, 0xffff);
 }
 
-static inline void msg_set_adv_win(struct tipc_msg *m, u32 n)
+static inline void msg_set_adv_win(struct tipc_msg *m, u16 n)
 {
 	msg_set_bits(m, 9, 0, 0xffff, n);
 }
@@ -794,6 +832,68 @@ static inline void msg_set_link_tolerance(struct tipc_msg *m, u32 n)
 	msg_set_bits(m, 9, 0, 0xffff, n);
 }
 
+static inline u16 msg_grp_bc_syncpt(struct tipc_msg *m)
+{
+	return msg_bits(m, 9, 16, 0xffff);
+}
+
+static inline void msg_set_grp_bc_syncpt(struct tipc_msg *m, u16 n)
+{
+	msg_set_bits(m, 9, 16, 0xffff, n);
+}
+
+static inline u16 msg_grp_bc_acked(struct tipc_msg *m)
+{
+	return msg_bits(m, 9, 16, 0xffff);
+}
+
+static inline void msg_set_grp_bc_acked(struct tipc_msg *m, u16 n)
+{
+	msg_set_bits(m, 9, 16, 0xffff, n);
+}
+
+static inline u16 msg_grp_remitted(struct tipc_msg *m)
+{
+	return msg_bits(m, 9, 16, 0xffff);
+}
+
+static inline void msg_set_grp_remitted(struct tipc_msg *m, u16 n)
+{
+	msg_set_bits(m, 9, 16, 0xffff, n);
+}
+
+/* Word 10
+ */
+static inline u16 msg_grp_evt(struct tipc_msg *m)
+{
+	return msg_bits(m, 10, 0, 0x3);
+}
+
+static inline void msg_set_grp_evt(struct tipc_msg *m, int n)
+{
+	msg_set_bits(m, 10, 0, 0x3, n);
+}
+
+static inline u16 msg_grp_bc_ack_req(struct tipc_msg *m)
+{
+	return msg_bits(m, 10, 0, 0x1);
+}
+
+static inline void msg_set_grp_bc_ack_req(struct tipc_msg *m, bool n)
+{
+	msg_set_bits(m, 10, 0, 0x1, n);
+}
+
+static inline u16 msg_grp_bc_seqno(struct tipc_msg *m)
+{
+	return msg_bits(m, 10, 16, 0xffff);
+}
+
+static inline void msg_set_grp_bc_seqno(struct tipc_msg *m, u32 n)
+{
+	msg_set_bits(m, 10, 16, 0xffff, n);
+}
+
 static inline bool msg_peer_link_is_up(struct tipc_msg *m)
 {
 	if (likely(msg_user(m) != LINK_PROTOCOL))
@@ -818,6 +918,8 @@ static inline bool msg_is_reset(struct tipc_msg *hdr)
 struct sk_buff *tipc_buf_acquire(u32 size, gfp_t gfp);
 bool tipc_msg_validate(struct sk_buff *skb);
 bool tipc_msg_reverse(u32 own_addr, struct sk_buff **skb, int err);
+void tipc_skb_reject(struct net *net, int err, struct sk_buff *skb,
+		     struct sk_buff_head *xmitq);
 void tipc_msg_init(u32 own_addr, struct tipc_msg *m, u32 user, u32 type,
 		   u32 hsize, u32 destnode);
 struct sk_buff *tipc_msg_create(uint user, uint type, uint hdr_sz,

net/tipc/name_table.c

@@ -43,6 +43,7 @@
 #include "bcast.h"
 #include "addr.h"
 #include "node.h"
+#include "group.h"
 #include <net/genetlink.h>
 
 #define TIPC_NAMETBL_SIZE 1024		/* must be a power of 2 */
@@ -596,18 +597,47 @@ u32 tipc_nametbl_translate(struct net *net, u32 type, u32 instance,
 	return ref;
 }
 
-/**
- * tipc_nametbl_mc_translate - find multicast destinations
- *
- * Creates list of all local ports that overlap the given multicast address;
- * also determines if any off-node ports overlap.
- *
- * Note: Publications with a scope narrower than 'limit' are ignored.
- * (i.e. local node-scope publications mustn't receive messages arriving
- * from another node, even if the multcast link brought it here)
- *
- * Returns non-zero if any off-node ports overlap
- */
+bool tipc_nametbl_lookup(struct net *net, u32 type, u32 instance, u32 domain,
+			 struct list_head *dsts, int *dstcnt, u32 exclude,
+			 bool all)
+{
+	u32 self = tipc_own_addr(net);
+	struct publication *publ;
+	struct name_info *info;
+	struct name_seq *seq;
+	struct sub_seq *sseq;
+
+	if (!tipc_in_scope(domain, self))
+		return false;
+
+	*dstcnt = 0;
+	rcu_read_lock();
+	seq = nametbl_find_seq(net, type);
+	if (unlikely(!seq))
+		goto exit;
+	spin_lock_bh(&seq->lock);
+	sseq = nameseq_find_subseq(seq, instance);
+	if (likely(sseq)) {
+		info = sseq->info;
+		list_for_each_entry(publ, &info->zone_list, zone_list) {
+			if (!tipc_in_scope(domain, publ->node))
+				continue;
+			if (publ->ref == exclude && publ->node == self)
+				continue;
+			tipc_dest_push(dsts, publ->node, publ->ref);
+			(*dstcnt)++;
+			if (all)
+				continue;
+			list_move_tail(&publ->zone_list, &info->zone_list);
+			break;
+		}
+	}
+	spin_unlock_bh(&seq->lock);
+exit:
+	rcu_read_unlock();
+	return !list_empty(dsts);
+}
+
 int tipc_nametbl_mc_translate(struct net *net, u32 type, u32 lower, u32 upper,
 			      u32 limit, struct list_head *dports)
 {
@@ -634,7 +664,7 @@ int tipc_nametbl_mc_translate(struct net *net, u32 type, u32 lower, u32 upper,
 		info = sseq->info;
 		list_for_each_entry(publ, &info->node_list, node_list) {
 			if (publ->scope <= limit)
-				u32_push(dports, publ->ref);
+				tipc_dest_push(dports, 0, publ->ref);
 		}
 
 		if (info->cluster_list_size != info->node_list_size)
@@ -679,6 +709,37 @@ void tipc_nametbl_lookup_dst_nodes(struct net *net, u32 type, u32 lower,
 	rcu_read_unlock();
 }
 
+/* tipc_nametbl_build_group - build list of communication group members
+ */
+void tipc_nametbl_build_group(struct net *net, struct tipc_group *grp,
+			      u32 type, u32 domain)
+{
+	struct sub_seq *sseq, *stop;
+	struct name_info *info;
+	struct publication *p;
+	struct name_seq *seq;
+
+	rcu_read_lock();
+	seq = nametbl_find_seq(net, type);
+	if (!seq)
+		goto exit;
+
+	spin_lock_bh(&seq->lock);
+	sseq = seq->sseqs;
+	stop = seq->sseqs + seq->first_free;
+	for (; sseq != stop; sseq++) {
+		info = sseq->info;
+		list_for_each_entry(p, &info->zone_list, zone_list) {
+			if (!tipc_in_scope(domain, p->node))
+				continue;
+			tipc_group_add_member(grp, p->node, p->ref);
+		}
+	}
+	spin_unlock_bh(&seq->lock);
+exit:
+	rcu_read_unlock();
+}
+
 /*
  * tipc_nametbl_publish - add name publication to network name tables
  */
@@ -1057,78 +1118,79 @@ int tipc_nl_name_table_dump(struct sk_buff *skb, struct netlink_callback *cb)
 	return skb->len;
 }
 
-bool u32_find(struct list_head *l, u32 value)
+struct tipc_dest *tipc_dest_find(struct list_head *l, u32 node, u32 port)
 {
-	struct u32_item *item;
+	u64 value = (u64)node << 32 | port;
+	struct tipc_dest *dst;
 
-	list_for_each_entry(item, l, list) {
-		if (item->value == value)
-			return true;
+	list_for_each_entry(dst, l, list) {
+		if (dst->value != value)
+			continue;
+		return dst;
 	}
-	return false;
+	return NULL;
 }
 
-bool u32_push(struct list_head *l, u32 value)
+bool tipc_dest_push(struct list_head *l, u32 node, u32 port)
 {
-	struct u32_item *item;
+	u64 value = (u64)node << 32 | port;
+	struct tipc_dest *dst;
 
-	list_for_each_entry(item, l, list) {
-		if (item->value == value)
-			return false;
-	}
-	item = kmalloc(sizeof(*item), GFP_ATOMIC);
-	if (unlikely(!item))
+	if (tipc_dest_find(l, node, port))
 		return false;
 
-	item->value = value;
-	list_add(&item->list, l);
+	dst = kmalloc(sizeof(*dst), GFP_ATOMIC);
+	if (unlikely(!dst))
+		return false;
+	dst->value = value;
+	list_add(&dst->list, l);
 	return true;
 }
 
-u32 u32_pop(struct list_head *l)
+bool tipc_dest_pop(struct list_head *l, u32 *node, u32 *port)
 {
-	struct u32_item *item;
-	u32 value = 0;
+	struct tipc_dest *dst;
 
 	if (list_empty(l))
-		return 0;
-	item = list_first_entry(l, typeof(*item), list);
-	value = item->value;
-	list_del(&item->list);
-	kfree(item);
-	return value;
+		return false;
+	dst = list_first_entry(l, typeof(*dst), list);
+	if (port)
+		*port = dst->port;
+	if (node)
+		*node = dst->node;
+	list_del(&dst->list);
+	kfree(dst);
+	return true;
 }
 
-bool u32_del(struct list_head *l, u32 value)
+bool tipc_dest_del(struct list_head *l, u32 node, u32 port)
 {
-	struct u32_item *item, *tmp;
+	struct tipc_dest *dst;
 
-	list_for_each_entry_safe(item, tmp, l, list) {
-		if (item->value != value)
-			continue;
-		list_del(&item->list);
-		kfree(item);
-		return true;
-	}
+	dst = tipc_dest_find(l, node, port);
+	if (!dst)
 		return false;
+	list_del(&dst->list);
+	kfree(dst);
+	return true;
 }
 
-void u32_list_purge(struct list_head *l)
+void tipc_dest_list_purge(struct list_head *l)
 {
-	struct u32_item *item, *tmp;
+	struct tipc_dest *dst, *tmp;
 
-	list_for_each_entry_safe(item, tmp, l, list) {
-		list_del(&item->list);
-		kfree(item);
+	list_for_each_entry_safe(dst, tmp, l, list) {
+		list_del(&dst->list);
+		kfree(dst);
 	}
 }
 
-int u32_list_len(struct list_head *l)
+int tipc_dest_list_len(struct list_head *l)
 {
-	struct u32_item *item;
+	struct tipc_dest *dst;
 	int i = 0;
 
-	list_for_each_entry(item, l, list) {
+	list_for_each_entry(dst, l, list) {
 		i++;
 	}
 	return i;

net/tipc/name_table.h

@@ -40,6 +40,7 @@
 struct tipc_subscription;
 struct tipc_plist;
 struct tipc_nlist;
+struct tipc_group;
 
 /*
  * TIPC name types reserved for internal TIPC use (both current and planned)
@@ -101,9 +102,14 @@ int tipc_nl_name_table_dump(struct sk_buff *skb, struct netlink_callback *cb);
 u32 tipc_nametbl_translate(struct net *net, u32 type, u32 instance, u32 *node);
 int tipc_nametbl_mc_translate(struct net *net, u32 type, u32 lower, u32 upper,
 			      u32 limit, struct list_head *dports);
+void tipc_nametbl_build_group(struct net *net, struct tipc_group *grp,
+			      u32 type, u32 domain);
 void tipc_nametbl_lookup_dst_nodes(struct net *net, u32 type, u32 lower,
 				   u32 upper, u32 domain,
 				   struct tipc_nlist *nodes);
+bool tipc_nametbl_lookup(struct net *net, u32 type, u32 instance, u32 domain,
+			 struct list_head *dsts, int *dstcnt, u32 exclude,
+			 bool all);
 struct publication *tipc_nametbl_publish(struct net *net, u32 type, u32 lower,
 					 u32 upper, u32 scope, u32 port_ref,
 					 u32 key);
@@ -120,16 +126,22 @@ void tipc_nametbl_unsubscribe(struct tipc_subscription *s);
 int tipc_nametbl_init(struct net *net);
 void tipc_nametbl_stop(struct net *net);
 
-struct u32_item {
+struct tipc_dest {
 	struct list_head list;
-	u32 value;
+	union {
+		struct {
+			u32 port;
+			u32 node;
+		};
+		u64 value;
+	};
 };
 
-bool u32_push(struct list_head *l, u32 value);
-u32 u32_pop(struct list_head *l);
-bool u32_find(struct list_head *l, u32 value);
-bool u32_del(struct list_head *l, u32 value);
-void u32_list_purge(struct list_head *l);
-int u32_list_len(struct list_head *l);
+struct tipc_dest *tipc_dest_find(struct list_head *l, u32 node, u32 port);
+bool tipc_dest_push(struct list_head *l, u32 node, u32 port);
+bool tipc_dest_pop(struct list_head *l, u32 *node, u32 *port);
+bool tipc_dest_del(struct list_head *l, u32 node, u32 port);
+void tipc_dest_list_purge(struct list_head *l);
+int tipc_dest_list_len(struct list_head *l);
 
 #endif

net/tipc/node.c

@@ -157,7 +157,7 @@ static void tipc_node_timeout(unsigned long data);
 static void tipc_node_fsm_evt(struct tipc_node *n, int evt);
 static struct tipc_node *tipc_node_find(struct net *net, u32 addr);
 static void tipc_node_put(struct tipc_node *node);
-static bool tipc_node_is_up(struct tipc_node *n);
+static bool node_is_up(struct tipc_node *n);
 
 struct tipc_sock_conn {
 	u32 port;
@@ -657,7 +657,7 @@ static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
 		*slot1 = i;
 	}
 
-	if (!tipc_node_is_up(n)) {
+	if (!node_is_up(n)) {
 		if (tipc_link_peer_is_down(l))
 			tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
 		tipc_node_fsm_evt(n, SELF_LOST_CONTACT_EVT);
@@ -717,11 +717,27 @@ static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
 	tipc_sk_rcv(n->net, &le->inputq);
 }
 
-static bool tipc_node_is_up(struct tipc_node *n)
+static bool node_is_up(struct tipc_node *n)
 {
 	return n->active_links[0] != INVALID_BEARER_ID;
 }
 
+bool tipc_node_is_up(struct net *net, u32 addr)
+{
+	struct tipc_node *n;
+	bool retval = false;
+
+	if (in_own_node(net, addr))
+		return true;
+
+	n = tipc_node_find(net, addr);
+	if (!n)
+		return false;
+	retval = node_is_up(n);
+	tipc_node_put(n);
+	return retval;
+}
+
 void tipc_node_check_dest(struct net *net, u32 onode,
 			  struct tipc_bearer *b,
 			  u16 capabilities, u32 signature,
@@ -1149,7 +1165,7 @@ static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node)
 
 	if (nla_put_u32(msg->skb, TIPC_NLA_NODE_ADDR, node->addr))
 		goto attr_msg_full;
-	if (tipc_node_is_up(node))
+	if (node_is_up(node))
 		if (nla_put_flag(msg->skb, TIPC_NLA_NODE_UP))
 			goto attr_msg_full;
 
@@ -1238,6 +1254,22 @@ int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
 	return 0;
 }
 
+/* tipc_node_distr_xmit(): send single buffer msgs to individual destinations
+ * Note: this is only for SYSTEM_IMPORTANCE messages, which cannot be rejected
+ */
+int tipc_node_distr_xmit(struct net *net, struct sk_buff_head *xmitq)
+{
+	struct sk_buff *skb;
+	u32 selector, dnode;
+
+	while ((skb = __skb_dequeue(xmitq))) {
+		selector = msg_origport(buf_msg(skb));
+		dnode = msg_destnode(buf_msg(skb));
+		tipc_node_xmit_skb(net, skb, dnode, selector);
+	}
+	return 0;
+}
+
 void tipc_node_broadcast(struct net *net, struct sk_buff *skb)
 {
 	struct sk_buff *txskb;
@@ -1249,7 +1281,7 @@ void tipc_node_broadcast(struct net *net, struct sk_buff *skb)
 		dst = n->addr;
 		if (in_own_node(net, dst))
 			continue;
-		if (!tipc_node_is_up(n))
+		if (!node_is_up(n))
 			continue;
 		txskb = pskb_copy(skb, GFP_ATOMIC);
 		if (!txskb)

net/tipc/node.h

@@ -48,7 +48,8 @@ enum {
 	TIPC_BCAST_SYNCH      = (1 << 1),
 	TIPC_BCAST_STATE_NACK = (1 << 2),
 	TIPC_BLOCK_FLOWCTL    = (1 << 3),
-	TIPC_BCAST_RCAST      = (1 << 4)
+	TIPC_BCAST_RCAST      = (1 << 4),
+	TIPC_MCAST_GROUPS     = (1 << 5)
 };
 
 #define TIPC_NODE_CAPABILITIES (TIPC_BCAST_SYNCH | \
@@ -68,6 +69,7 @@ int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 node,
 			   char *linkname, size_t len);
 int tipc_node_xmit(struct net *net, struct sk_buff_head *list, u32 dnode,
 		   int selector);
+int tipc_node_distr_xmit(struct net *net, struct sk_buff_head *list);
 int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dest,
 		       u32 selector);
 void tipc_node_subscribe(struct net *net, struct list_head *subscr, u32 addr);
@@ -76,6 +78,7 @@ void tipc_node_broadcast(struct net *net, struct sk_buff *skb);
 int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port);
 void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port);
 int tipc_node_get_mtu(struct net *net, u32 addr, u32 sel);
+bool tipc_node_is_up(struct net *net, u32 addr);
 u16 tipc_node_get_capabilities(struct net *net, u32 addr);
 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb);
 int tipc_nl_node_dump_link(struct sk_buff *skb, struct netlink_callback *cb);

net/tipc/server.c

@@ -36,6 +36,8 @@
 #include "server.h"
 #include "core.h"
 #include "socket.h"
+#include "addr.h"
+#include "msg.h"
 #include <net/sock.h>
 #include <linux/module.h>
 
@@ -105,13 +107,11 @@ static void tipc_conn_kref_release(struct kref *kref)
 		kernel_bind(sock, (struct sockaddr *)saddr, sizeof(*saddr));
 		sock_release(sock);
 		con->sock = NULL;
-
+	}
 	spin_lock_bh(&s->idr_lock);
 	idr_remove(&s->conn_idr, con->conid);
 	s->idr_in_use--;
 	spin_unlock_bh(&s->idr_lock);
-	}
-
 	tipc_clean_outqueues(con);
 	kfree(con);
 }
@@ -197,6 +197,7 @@ static void tipc_close_conn(struct tipc_conn *con)
 	struct tipc_server *s = con->server;
 
 	if (test_and_clear_bit(CF_CONNECTED, &con->flags)) {
+		if (con->sock)
 			tipc_unregister_callbacks(con);
 
 		if (con->conid)
@@ -207,8 +208,8 @@ static void tipc_close_conn(struct tipc_conn *con)
 		 * are harmless for us here as we have already deleted this
 		 * connection from server connection list.
 		 */
+		if (con->sock)
 			kernel_sock_shutdown(con->sock, SHUT_RDWR);
-
 		conn_put(con);
 	}
 }
@@ -487,25 +488,88 @@ void tipc_conn_terminate(struct tipc_server *s, int conid)
 	}
 }
 
+bool tipc_topsrv_kern_subscr(struct net *net, u32 port, u32 type,
+			     u32 lower, u32 upper, int *conid)
+{
+	struct tipc_subscriber *scbr;
+	struct tipc_subscr sub;
+	struct tipc_server *s;
+	struct tipc_conn *con;
+
+	sub.seq.type = type;
+	sub.seq.lower = lower;
+	sub.seq.upper = upper;
+	sub.timeout = TIPC_WAIT_FOREVER;
+	sub.filter = TIPC_SUB_PORTS;
+	*(u32 *)&sub.usr_handle = port;
+
+	con = tipc_alloc_conn(tipc_topsrv(net));
+	if (!con)
+		return false;
+
+	*conid = con->conid;
+	s = con->server;
+	scbr = s->tipc_conn_new(*conid);
+	if (!scbr) {
+		tipc_close_conn(con);
+		return false;
+	}
+
+	con->usr_data = scbr;
+	con->sock = NULL;
+	s->tipc_conn_recvmsg(net, *conid, NULL, scbr, &sub, sizeof(sub));
+	return true;
+}
+
+void tipc_topsrv_kern_unsubscr(struct net *net, int conid)
+{
+	struct tipc_conn *con;
+
+	con = tipc_conn_lookup(tipc_topsrv(net), conid);
+	if (!con)
+		return;
+	tipc_close_conn(con);
+	conn_put(con);
+}
+
+static void tipc_send_kern_top_evt(struct net *net, struct tipc_event *evt)
+{
+	u32 port = *(u32 *)&evt->s.usr_handle;
+	u32 self = tipc_own_addr(net);
+	struct sk_buff_head evtq;
+	struct sk_buff *skb;
+
+	skb = tipc_msg_create(TOP_SRV, 0, INT_H_SIZE, sizeof(*evt),
+			      self, self, port, port, 0);
+	if (!skb)
+		return;
+	msg_set_dest_droppable(buf_msg(skb), true);
+	memcpy(msg_data(buf_msg(skb)), evt, sizeof(*evt));
+	skb_queue_head_init(&evtq);
+	__skb_queue_tail(&evtq, skb);
+	tipc_sk_rcv(net, &evtq);
+}
+
 static void tipc_send_to_sock(struct tipc_conn *con)
 {
-	int count = 0;
 	struct tipc_server *s = con->server;
 	struct outqueue_entry *e;
+	struct tipc_event *evt;
 	struct msghdr msg;
+	int count = 0;
 	int ret;
 
 	spin_lock_bh(&con->outqueue_lock);
 	while (test_bit(CF_CONNECTED, &con->flags)) {
-		e = list_entry(con->outqueue.next, struct outqueue_entry,
-			       list);
+		e = list_entry(con->outqueue.next, struct outqueue_entry, list);
 		if ((struct list_head *) e == &con->outqueue)
 			break;
+
 		spin_unlock_bh(&con->outqueue_lock);
 
+		if (con->sock) {
 			memset(&msg, 0, sizeof(msg));
 			msg.msg_flags = MSG_DONTWAIT;
-
 			if (s->type == SOCK_DGRAM || s->type == SOCK_RDM) {
 				msg.msg_name = &e->dest;
 				msg.msg_namelen = sizeof(struct sockaddr_tipc);
@@ -518,7 +582,10 @@ static void tipc_send_to_sock(struct tipc_conn *con)
 			} else if (ret < 0) {
 				goto send_err;
 			}
-
+		} else {
+			evt = e->iov.iov_base;
+			tipc_send_kern_top_evt(s->net, evt);
+		}
 		/* Don't starve users filling buffers */
 		if (++count >= MAX_SEND_MSG_COUNT) {
 			cond_resched();

net/tipc/server.h

@@ -83,13 +83,16 @@ struct tipc_server {
 int tipc_conn_sendmsg(struct tipc_server *s, int conid,
 		      struct sockaddr_tipc *addr, void *data, size_t len);
 
+bool tipc_topsrv_kern_subscr(struct net *net, u32 port, u32 type,
+			     u32 lower, u32 upper, int *conid);
+void tipc_topsrv_kern_unsubscr(struct net *net, int conid);
+
 /**
  * tipc_conn_terminate - terminate connection with server
  *
  * Note: Must call it in process context since it might sleep
  */
 void tipc_conn_terminate(struct tipc_server *s, int conid);
-
 int tipc_server_start(struct tipc_server *s);
 
 void tipc_server_stop(struct tipc_server *s);

net/tipc/socket.c

 /*
  * net/tipc/socket.c: TIPC socket API
  *
- * Copyright (c) 2001-2007, 2012-2016, Ericsson AB
+ * Copyright (c) 2001-2007, 2012-2017, Ericsson AB
  * Copyright (c) 2004-2008, 2010-2013, Wind River Systems
  * All rights reserved.
  *
@@ -45,6 +45,7 @@
 #include "socket.h"
 #include "bcast.h"
 #include "netlink.h"
+#include "group.h"
 
 #define CONN_TIMEOUT_DEFAULT	8000	/* default connect timeout = 8s */
 #define CONN_PROBING_INTERVAL	msecs_to_jiffies(3600000)  /* [ms] => 1 h */
@@ -61,6 +62,11 @@ enum {
 	TIPC_CONNECTING = TCP_SYN_SENT,
 };
 
+struct sockaddr_pair {
+	struct sockaddr_tipc sock;
+	struct sockaddr_tipc member;
+};
+
 /**
  * struct tipc_sock - TIPC socket structure
  * @sk: socket - interacts with 'port' and with user via the socket API
@@ -78,7 +84,7 @@ enum {
  * @conn_timeout: the time we can wait for an unresponded setup request
  * @dupl_rcvcnt: number of bytes counted twice, in both backlog and rcv queue
  * @cong_link_cnt: number of congested links
- * @sent_unacked: # messages sent by socket, and not yet acked by peer
+ * @snt_unacked: # messages sent by socket, and not yet acked by peer
  * @rcv_unacked: # messages read by user, but not yet acked back to peer
  * @peer: 'connected' peer for dgram/rdm
  * @node: hash table node
@@ -109,9 +115,10 @@ struct tipc_sock {
 	struct rhash_head node;
 	struct tipc_mc_method mc_method;
 	struct rcu_head rcu;
+	struct tipc_group *group;
 };
 
-static int tipc_backlog_rcv(struct sock *sk, struct sk_buff *skb);
+static int tipc_sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
 static void tipc_data_ready(struct sock *sk);
 static void tipc_write_space(struct sock *sk);
 static void tipc_sock_destruct(struct sock *sk);
@@ -123,6 +130,7 @@ static int tipc_sk_publish(struct tipc_sock *tsk, uint scope,
 			   struct tipc_name_seq const *seq);
 static int tipc_sk_withdraw(struct tipc_sock *tsk, uint scope,
 			    struct tipc_name_seq const *seq);
+static int tipc_sk_leave(struct tipc_sock *tsk);
 static struct tipc_sock *tipc_sk_lookup(struct net *net, u32 portid);
 static int tipc_sk_insert(struct tipc_sock *tsk);
 static void tipc_sk_remove(struct tipc_sock *tsk);
@@ -193,6 +201,11 @@ static bool tsk_conn_cong(struct tipc_sock *tsk)
 	return tsk->snt_unacked > tsk->snd_win;
 }
 
+static u16 tsk_blocks(int len)
+{
+	return ((len / FLOWCTL_BLK_SZ) + 1);
+}
+
 /* tsk_blocks(): translate a buffer size in bytes to number of
  * advertisable blocks, taking into account the ratio truesize(len)/len
  * We can trust that this ratio is always < 4 for len >= FLOWCTL_BLK_SZ
@@ -453,7 +466,7 @@ static int tipc_sk_create(struct net *net, struct socket *sock,
 	msg_set_origport(msg, tsk->portid);
 	setup_timer(&sk->sk_timer, tipc_sk_timeout, (unsigned long)tsk);
 	sk->sk_shutdown = 0;
-	sk->sk_backlog_rcv = tipc_backlog_rcv;
+	sk->sk_backlog_rcv = tipc_sk_backlog_rcv;
 	sk->sk_rcvbuf = sysctl_tipc_rmem[1];
 	sk->sk_data_ready = tipc_data_ready;
 	sk->sk_write_space = tipc_write_space;
@@ -559,13 +572,14 @@ static int tipc_release(struct socket *sock)
 
 	__tipc_shutdown(sock, TIPC_ERR_NO_PORT);
 	sk->sk_shutdown = SHUTDOWN_MASK;
+	tipc_sk_leave(tsk);
 	tipc_sk_withdraw(tsk, 0, NULL);
 	sk_stop_timer(sk, &sk->sk_timer);
 	tipc_sk_remove(tsk);
 
 	/* Reject any messages that accumulated in backlog queue */
 	release_sock(sk);
-	u32_list_purge(&tsk->cong_links);
+	tipc_dest_list_purge(&tsk->cong_links);
 	tsk->cong_link_cnt = 0;
 	call_rcu(&tsk->rcu, tipc_sk_callback);
 	sock->sk = NULL;
@@ -601,7 +615,10 @@ static int tipc_bind(struct socket *sock, struct sockaddr *uaddr,
 		res = tipc_sk_withdraw(tsk, 0, NULL);
 		goto exit;
 	}
-
+	if (tsk->group) {
+		res = -EACCES;
+		goto exit;
+	}
 	if (uaddr_len < sizeof(struct sockaddr_tipc)) {
 		res = -EINVAL;
 		goto exit;
@@ -697,39 +714,43 @@ static unsigned int tipc_poll(struct file *file, struct socket *sock,
 			      poll_table *wait)
 {
 	struct sock *sk = sock->sk;
+	struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
 	struct tipc_sock *tsk = tipc_sk(sk);
-	u32 mask = 0;
+	struct tipc_group *grp = tsk->group;
+	u32 revents = 0;
 
 	sock_poll_wait(file, sk_sleep(sk), wait);
 
 	if (sk->sk_shutdown & RCV_SHUTDOWN)
-		mask |= POLLRDHUP | POLLIN | POLLRDNORM;
+		revents |= POLLRDHUP | POLLIN | POLLRDNORM;
 	if (sk->sk_shutdown == SHUTDOWN_MASK)
-		mask |= POLLHUP;
+		revents |= POLLHUP;
 
 	switch (sk->sk_state) {
 	case TIPC_ESTABLISHED:
 		if (!tsk->cong_link_cnt && !tsk_conn_cong(tsk))
-			mask |= POLLOUT;
+			revents |= POLLOUT;
 		/* fall thru' */
 	case TIPC_LISTEN:
 	case TIPC_CONNECTING:
-		if (!skb_queue_empty(&sk->sk_receive_queue))
-			mask |= (POLLIN | POLLRDNORM);
+		if (skb)
+			revents |= POLLIN | POLLRDNORM;
 		break;
 	case TIPC_OPEN:
+		if (!grp || tipc_group_size(grp))
 			if (!tsk->cong_link_cnt)
-			mask |= POLLOUT;
-		if (tipc_sk_type_connectionless(sk) &&
-		    (!skb_queue_empty(&sk->sk_receive_queue)))
-			mask |= (POLLIN | POLLRDNORM);
+				revents |= POLLOUT;
+		if (!tipc_sk_type_connectionless(sk))
+			break;
+		if (!skb)
+			break;
+		revents |= POLLIN | POLLRDNORM;
 		break;
 	case TIPC_DISCONNECTING:
-		mask = (POLLIN | POLLRDNORM | POLLHUP);
+		revents = POLLIN | POLLRDNORM | POLLHUP;
 		break;
 	}
-
-	return mask;
+	return revents;
 }
 
 /**
@@ -757,6 +778,9 @@ static int tipc_sendmcast(struct  socket *sock, struct tipc_name_seq *seq,
 	struct tipc_nlist dsts;
 	int rc;
 
+	if (tsk->group)
+		return -EACCES;
+
 	/* Block or return if any destination link is congested */
 	rc = tipc_wait_for_cond(sock, &timeout, !tsk->cong_link_cnt);
 	if (unlikely(rc))
@@ -793,6 +817,296 @@ static int tipc_sendmcast(struct  socket *sock, struct tipc_name_seq *seq,
 	return rc ? rc : dlen;
 }
 
+/**
+ * tipc_send_group_msg - send a message to a member in the group
+ * @net: network namespace
+ * @m: message to send
+ * @mb: group member
+ * @dnode: destination node
+ * @dport: destination port
+ * @dlen: total length of message data
+ */
+static int tipc_send_group_msg(struct net *net, struct tipc_sock *tsk,
+			       struct msghdr *m, struct tipc_member *mb,
+			       u32 dnode, u32 dport, int dlen)
+{
+	u16 bc_snd_nxt = tipc_group_bc_snd_nxt(tsk->group);
+	struct tipc_mc_method *method = &tsk->mc_method;
+	int blks = tsk_blocks(GROUP_H_SIZE + dlen);
+	struct tipc_msg *hdr = &tsk->phdr;
+	struct sk_buff_head pkts;
+	int mtu, rc;
+
+	/* Complete message header */
+	msg_set_type(hdr, TIPC_GRP_UCAST_MSG);
+	msg_set_hdr_sz(hdr, GROUP_H_SIZE);
+	msg_set_destport(hdr, dport);
+	msg_set_destnode(hdr, dnode);
+	msg_set_grp_bc_seqno(hdr, bc_snd_nxt);
+
+	/* Build message as chain of buffers */
+	skb_queue_head_init(&pkts);
+	mtu = tipc_node_get_mtu(net, dnode, tsk->portid);
+	rc = tipc_msg_build(hdr, m, 0, dlen, mtu, &pkts);
+	if (unlikely(rc != dlen))
+		return rc;
+
+	/* Send message */
+	rc = tipc_node_xmit(net, &pkts, dnode, tsk->portid);
+	if (unlikely(rc == -ELINKCONG)) {
+		tipc_dest_push(&tsk->cong_links, dnode, 0);
+		tsk->cong_link_cnt++;
+	}
+
+	/* Update send window */
+	tipc_group_update_member(mb, blks);
+
+	/* A broadcast sent within next EXPIRE period must follow same path */
+	method->rcast = true;
+	method->mandatory = true;
+	return dlen;
+}
+
+/**
+ * tipc_send_group_unicast - send message to a member in the group
+ * @sock: socket structure
+ * @m: message to send
+ * @dlen: total length of message data
+ * @timeout: timeout to wait for wakeup
+ *
+ * Called from function tipc_sendmsg(), which has done all sanity checks
+ * Returns the number of bytes sent on success, or errno
+ */
+static int tipc_send_group_unicast(struct socket *sock, struct msghdr *m,
+				   int dlen, long timeout)
+{
+	struct sock *sk = sock->sk;
+	DECLARE_SOCKADDR(struct sockaddr_tipc *, dest, m->msg_name);
+	int blks = tsk_blocks(GROUP_H_SIZE + dlen);
+	struct tipc_sock *tsk = tipc_sk(sk);
+	struct tipc_group *grp = tsk->group;
+	struct net *net = sock_net(sk);
+	struct tipc_member *mb = NULL;
+	u32 node, port;
+	int rc;
+
+	node = dest->addr.id.node;
+	port = dest->addr.id.ref;
+	if (!port && !node)
+		return -EHOSTUNREACH;
+
+	/* Block or return if destination link or member is congested */
+	rc = tipc_wait_for_cond(sock, &timeout,
+				!tipc_dest_find(&tsk->cong_links, node, 0) &&
+				!tipc_group_cong(grp, node, port, blks, &mb));
+	if (unlikely(rc))
+		return rc;
+
+	if (unlikely(!mb))
+		return -EHOSTUNREACH;
+
+	rc = tipc_send_group_msg(net, tsk, m, mb, node, port, dlen);
+
+	return rc ? rc : dlen;
+}
+
+/**
+ * tipc_send_group_anycast - send message to any member with given identity
+ * @sock: socket structure
+ * @m: message to send
+ * @dlen: total length of message data
+ * @timeout: timeout to wait for wakeup
+ *
+ * Called from function tipc_sendmsg(), which has done all sanity checks
+ * Returns the number of bytes sent on success, or errno
+ */
+static int tipc_send_group_anycast(struct socket *sock, struct msghdr *m,
+				   int dlen, long timeout)
+{
+	DECLARE_SOCKADDR(struct sockaddr_tipc *, dest, m->msg_name);
+	struct sock *sk = sock->sk;
+	struct tipc_sock *tsk = tipc_sk(sk);
+	struct list_head *cong_links = &tsk->cong_links;
+	int blks = tsk_blocks(GROUP_H_SIZE + dlen);
+	struct tipc_group *grp = tsk->group;
+	struct tipc_member *first = NULL;
+	struct tipc_member *mbr = NULL;
+	struct net *net = sock_net(sk);
+	u32 node, port, exclude;
+	u32 type, inst, domain;
+	struct list_head dsts;
+	int lookups = 0;
+	int dstcnt, rc;
+	bool cong;
+
+	INIT_LIST_HEAD(&dsts);
+
+	type = dest->addr.name.name.type;
+	inst = dest->addr.name.name.instance;
+	domain = addr_domain(net, dest->scope);
+	exclude = tipc_group_exclude(grp);
+
+	while (++lookups < 4) {
+		first = NULL;
+
+		/* Look for a non-congested destination member, if any */
+		while (1) {
+			if (!tipc_nametbl_lookup(net, type, inst, domain, &dsts,
+						 &dstcnt, exclude, false))
+				return -EHOSTUNREACH;
+			tipc_dest_pop(&dsts, &node, &port);
+			cong = tipc_group_cong(grp, node, port, blks, &mbr);
+			if (!cong)
+				break;
+			if (mbr == first)
+				break;
+			if (!first)
+				first = mbr;
+		}
+
+		/* Start over if destination was not in member list */
+		if (unlikely(!mbr))
+			continue;
+
+		if (likely(!cong && !tipc_dest_find(cong_links, node, 0)))
+			break;
+
+		/* Block or return if destination link or member is congested */
+		rc = tipc_wait_for_cond(sock, &timeout,
+					!tipc_dest_find(cong_links, node, 0) &&
+					!tipc_group_cong(grp, node, port,
+							 blks, &mbr));
+		if (unlikely(rc))
+			return rc;
+
+		/* Send, unless destination disappeared while waiting */
+		if (likely(mbr))
+			break;
+	}
+
+	if (unlikely(lookups >= 4))
+		return -EHOSTUNREACH;
+
+	rc = tipc_send_group_msg(net, tsk, m, mbr, node, port, dlen);
+
+	return rc ? rc : dlen;
+}
+
+/**
+ * tipc_send_group_bcast - send message to all members in communication group
+ * @sk: socket structure
+ * @m: message to send
+ * @dlen: total length of message data
+ * @timeout: timeout to wait for wakeup
+ *
+ * Called from function tipc_sendmsg(), which has done all sanity checks
+ * Returns the number of bytes sent on success, or errno
+ */
+static int tipc_send_group_bcast(struct socket *sock, struct msghdr *m,
+				 int dlen, long timeout)
+{
+	DECLARE_SOCKADDR(struct sockaddr_tipc *, dest, m->msg_name);
+	struct sock *sk = sock->sk;
+	struct net *net = sock_net(sk);
+	struct tipc_sock *tsk = tipc_sk(sk);
+	struct tipc_group *grp = tsk->group;
+	struct tipc_nlist *dsts = tipc_group_dests(grp);
+	struct tipc_mc_method *method = &tsk->mc_method;
+	bool ack = method->mandatory && method->rcast;
+	int blks = tsk_blocks(MCAST_H_SIZE + dlen);
+	struct tipc_msg *hdr = &tsk->phdr;
+	int mtu = tipc_bcast_get_mtu(net);
+	struct sk_buff_head pkts;
+	int rc = -EHOSTUNREACH;
+
+	if (!dsts->local && !dsts->remote)
+		return -EHOSTUNREACH;
+
+	/* Block or return if any destination link or member is congested */
+	rc = tipc_wait_for_cond(sock, &timeout,	!tsk->cong_link_cnt &&
+				!tipc_group_bc_cong(grp, blks));
+	if (unlikely(rc))
+		return rc;
+
+	/* Complete message header */
+	if (dest) {
+		msg_set_type(hdr, TIPC_GRP_MCAST_MSG);
+		msg_set_nameinst(hdr, dest->addr.name.name.instance);
+	} else {
+		msg_set_type(hdr, TIPC_GRP_BCAST_MSG);
+		msg_set_nameinst(hdr, 0);
+	}
+	msg_set_hdr_sz(hdr, GROUP_H_SIZE);
+	msg_set_destport(hdr, 0);
+	msg_set_destnode(hdr, 0);
+	msg_set_grp_bc_seqno(hdr, tipc_group_bc_snd_nxt(grp));
+
+	/* Avoid getting stuck with repeated forced replicasts */
+	msg_set_grp_bc_ack_req(hdr, ack);
+
+	/* Build message as chain of buffers */
+	skb_queue_head_init(&pkts);
+	rc = tipc_msg_build(hdr, m, 0, dlen, mtu, &pkts);
+	if (unlikely(rc != dlen))
+		return rc;
+
+	/* Send message */
+	rc = tipc_mcast_xmit(net, &pkts, method, dsts, &tsk->cong_link_cnt);
+	if (unlikely(rc))
+		return rc;
+
+	/* Update broadcast sequence number and send windows */
+	tipc_group_update_bc_members(tsk->group, blks, ack);
+
+	/* Broadcast link is now free to choose method for next broadcast */
+	method->mandatory = false;
+	method->expires = jiffies;
+
+	return dlen;
+}
+
+/**
+ * tipc_send_group_mcast - send message to all members with given identity
+ * @sock: socket structure
+ * @m: message to send
+ * @dlen: total length of message data
+ * @timeout: timeout to wait for wakeup
+ *
+ * Called from function tipc_sendmsg(), which has done all sanity checks
+ * Returns the number of bytes sent on success, or errno
+ */
+static int tipc_send_group_mcast(struct socket *sock, struct msghdr *m,
+				 int dlen, long timeout)
+{
+	struct sock *sk = sock->sk;
+	DECLARE_SOCKADDR(struct sockaddr_tipc *, dest, m->msg_name);
+	struct tipc_name_seq *seq = &dest->addr.nameseq;
+	struct tipc_sock *tsk = tipc_sk(sk);
+	struct tipc_group *grp = tsk->group;
+	struct net *net = sock_net(sk);
+	u32 domain, exclude, dstcnt;
+	struct list_head dsts;
+
+	INIT_LIST_HEAD(&dsts);
+
+	if (seq->lower != seq->upper)
+		return -ENOTSUPP;
+
+	domain = addr_domain(net, dest->scope);
+	exclude = tipc_group_exclude(grp);
+	if (!tipc_nametbl_lookup(net, seq->type, seq->lower, domain,
+				 &dsts, &dstcnt, exclude, true))
+		return -EHOSTUNREACH;
+
+	if (dstcnt == 1) {
+		tipc_dest_pop(&dsts, &dest->addr.id.node, &dest->addr.id.ref);
+		return tipc_send_group_unicast(sock, m, dlen, timeout);
+	}
+
+	tipc_dest_list_purge(&dsts);
+	return tipc_send_group_bcast(sock, m, dlen, timeout);
+}
+
 /**
  * tipc_sk_mcast_rcv - Deliver multicast messages to all destination sockets
  * @arrvq: queue with arriving messages, to be cloned after destination lookup
@@ -803,13 +1117,15 @@ static int tipc_sendmcast(struct  socket *sock, struct tipc_name_seq *seq,
 void tipc_sk_mcast_rcv(struct net *net, struct sk_buff_head *arrvq,
 		       struct sk_buff_head *inputq)
 {
-	struct tipc_msg *msg;
-	struct list_head dports;
-	u32 portid;
 	u32 scope = TIPC_CLUSTER_SCOPE;
-	struct sk_buff_head tmpq;
-	uint hsz;
+	u32 self = tipc_own_addr(net);
 	struct sk_buff *skb, *_skb;
+	u32 lower = 0, upper = ~0;
+	struct sk_buff_head tmpq;
+	u32 portid, oport, onode;
+	struct list_head dports;
+	struct tipc_msg *msg;
+	int user, mtyp, hsz;
 
 	__skb_queue_head_init(&tmpq);
 	INIT_LIST_HEAD(&dports);
@@ -817,17 +1133,32 @@ void tipc_sk_mcast_rcv(struct net *net, struct sk_buff_head *arrvq,
 	skb = tipc_skb_peek(arrvq, &inputq->lock);
 	for (; skb; skb = tipc_skb_peek(arrvq, &inputq->lock)) {
 		msg = buf_msg(skb);
+		user = msg_user(msg);
+		mtyp = msg_type(msg);
+		if (mtyp == TIPC_GRP_UCAST_MSG || user == GROUP_PROTOCOL) {
+			spin_lock_bh(&inputq->lock);
+			if (skb_peek(arrvq) == skb) {
+				__skb_dequeue(arrvq);
+				__skb_queue_tail(inputq, skb);
+			}
+			refcount_dec(&skb->users);
+			spin_unlock_bh(&inputq->lock);
+			continue;
+		}
 		hsz = skb_headroom(skb) + msg_hdr_sz(msg);
-
-		if (in_own_node(net, msg_orignode(msg)))
+		oport = msg_origport(msg);
+		onode = msg_orignode(msg);
+		if (onode == self)
 			scope = TIPC_NODE_SCOPE;
 
 		/* Create destination port list and message clones: */
-		tipc_nametbl_mc_translate(net,
-					  msg_nametype(msg), msg_namelower(msg),
-					  msg_nameupper(msg), scope, &dports);
-		portid = u32_pop(&dports);
-		for (; portid; portid = u32_pop(&dports)) {
+		if (!msg_in_group(msg)) {
+			lower = msg_namelower(msg);
+			upper = msg_nameupper(msg);
+		}
+		tipc_nametbl_mc_translate(net, msg_nametype(msg), lower, upper,
+					  scope, &dports);
+		while (tipc_dest_pop(&dports, NULL, &portid)) {
 			_skb = __pskb_copy(skb, hsz, GFP_ATOMIC);
 			if (_skb) {
 				msg_set_destport(buf_msg(_skb), portid);
@@ -850,16 +1181,16 @@ void tipc_sk_mcast_rcv(struct net *net, struct sk_buff_head *arrvq,
 }
 
 /**
- * tipc_sk_proto_rcv - receive a connection mng protocol message
+ * tipc_sk_conn_proto_rcv - receive a connection mng protocol message
  * @tsk: receiving socket
  * @skb: pointer to message buffer.
  */
-static void tipc_sk_proto_rcv(struct tipc_sock *tsk, struct sk_buff *skb,
+static void tipc_sk_conn_proto_rcv(struct tipc_sock *tsk, struct sk_buff *skb,
 				   struct sk_buff_head *xmitq)
 {
-	struct sock *sk = &tsk->sk;
-	u32 onode = tsk_own_node(tsk);
 	struct tipc_msg *hdr = buf_msg(skb);
+	u32 onode = tsk_own_node(tsk);
+	struct sock *sk = &tsk->sk;
 	int mtyp = msg_type(hdr);
 	bool conn_cong;
 
@@ -931,6 +1262,7 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dlen)
 	long timeout = sock_sndtimeo(sk, m->msg_flags & MSG_DONTWAIT);
 	struct list_head *clinks = &tsk->cong_links;
 	bool syn = !tipc_sk_type_connectionless(sk);
+	struct tipc_group *grp = tsk->group;
 	struct tipc_msg *hdr = &tsk->phdr;
 	struct tipc_name_seq *seq;
 	struct sk_buff_head pkts;
@@ -941,18 +1273,31 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dlen)
 	if (unlikely(dlen > TIPC_MAX_USER_MSG_SIZE))
 		return -EMSGSIZE;
 
+	if (likely(dest)) {
+		if (unlikely(m->msg_namelen < sizeof(*dest)))
+			return -EINVAL;
+		if (unlikely(dest->family != AF_TIPC))
+			return -EINVAL;
+	}
+
+	if (grp) {
+		if (!dest)
+			return tipc_send_group_bcast(sock, m, dlen, timeout);
+		if (dest->addrtype == TIPC_ADDR_NAME)
+			return tipc_send_group_anycast(sock, m, dlen, timeout);
+		if (dest->addrtype == TIPC_ADDR_ID)
+			return tipc_send_group_unicast(sock, m, dlen, timeout);
+		if (dest->addrtype == TIPC_ADDR_MCAST)
+			return tipc_send_group_mcast(sock, m, dlen, timeout);
+		return -EINVAL;
+	}
+
 	if (unlikely(!dest)) {
 		dest = &tsk->peer;
 		if (!syn || dest->family != AF_TIPC)
 			return -EDESTADDRREQ;
 	}
 
-	if (unlikely(m->msg_namelen < sizeof(*dest)))
-		return -EINVAL;
-
-	if (unlikely(dest->family != AF_TIPC))
-		return -EINVAL;
-
 	if (unlikely(syn)) {
 		if (sk->sk_state == TIPC_LISTEN)
 			return -EPIPE;
@@ -985,7 +1330,6 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dlen)
 		msg_set_destport(hdr, dport);
 		if (unlikely(!dport && !dnode))
 			return -EHOSTUNREACH;
-
 	} else if (dest->addrtype == TIPC_ADDR_ID) {
 		dnode = dest->addr.id.node;
 		msg_set_type(hdr, TIPC_DIRECT_MSG);
@@ -996,7 +1340,8 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dlen)
 	}
 
 	/* Block or return if destination link is congested */
-	rc = tipc_wait_for_cond(sock, &timeout, !u32_find(clinks, dnode));
+	rc = tipc_wait_for_cond(sock, &timeout,
+				!tipc_dest_find(clinks, dnode, 0));
 	if (unlikely(rc))
 		return rc;
 
@@ -1008,7 +1353,7 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dlen)
 
 	rc = tipc_node_xmit(net, &pkts, dnode, tsk->portid);
 	if (unlikely(rc == -ELINKCONG)) {
-		u32_push(clinks, dnode);
+		tipc_dest_push(clinks, dnode, 0);
 		tsk->cong_link_cnt++;
 		rc = 0;
 	}
@@ -1142,26 +1487,38 @@ static void tipc_sk_finish_conn(struct tipc_sock *tsk, u32 peer_port,
 }
 
 /**
- * set_orig_addr - capture sender's address for received message
+ * tipc_sk_set_orig_addr - capture sender's address for received message
  * @m: descriptor for message info
- * @msg: received message header
+ * @hdr: received message header
  *
  * Note: Address is not captured if not requested by receiver.
  */
-static void set_orig_addr(struct msghdr *m, struct tipc_msg *msg)
+static void tipc_sk_set_orig_addr(struct msghdr *m, struct sk_buff *skb)
 {
-	DECLARE_SOCKADDR(struct sockaddr_tipc *, addr, m->msg_name);
+	DECLARE_SOCKADDR(struct sockaddr_pair *, srcaddr, m->msg_name);
+	struct tipc_msg *hdr = buf_msg(skb);
 
-	if (addr) {
-		addr->family = AF_TIPC;
-		addr->addrtype = TIPC_ADDR_ID;
-		memset(&addr->addr, 0, sizeof(addr->addr));
-		addr->addr.id.ref = msg_origport(msg);
-		addr->addr.id.node = msg_orignode(msg);
-		addr->addr.name.domain = 0;	/* could leave uninitialized */
-		addr->scope = 0;		/* could leave uninitialized */
+	if (!srcaddr)
+		return;
+
+	srcaddr->sock.family = AF_TIPC;
+	srcaddr->sock.addrtype = TIPC_ADDR_ID;
+	srcaddr->sock.addr.id.ref = msg_origport(hdr);
+	srcaddr->sock.addr.id.node = msg_orignode(hdr);
+	srcaddr->sock.addr.name.domain = 0;
+	srcaddr->sock.scope = 0;
 	m->msg_namelen = sizeof(struct sockaddr_tipc);
-	}
+
+	if (!msg_in_group(hdr))
+		return;
+
+	/* Group message users may also want to know sending member's id */
+	srcaddr->member.family = AF_TIPC;
+	srcaddr->member.addrtype = TIPC_ADDR_NAME;
+	srcaddr->member.addr.name.name.type = msg_nametype(hdr);
+	srcaddr->member.addr.name.name.instance = TIPC_SKB_CB(skb)->orig_member;
+	srcaddr->member.addr.name.domain = 0;
+	m->msg_namelen = sizeof(*srcaddr);
 }
 
 /**
@@ -1318,11 +1675,13 @@ static int tipc_recvmsg(struct socket *sock, struct msghdr *m,
 			size_t buflen,	int flags)
 {
 	struct sock *sk = sock->sk;
-	struct tipc_sock *tsk = tipc_sk(sk);
-	struct sk_buff *skb;
-	struct tipc_msg *hdr;
 	bool connected = !tipc_sk_type_connectionless(sk);
+	struct tipc_sock *tsk = tipc_sk(sk);
 	int rc, err, hlen, dlen, copy;
+	struct sk_buff_head xmitq;
+	struct tipc_msg *hdr;
+	struct sk_buff *skb;
+	bool grp_evt;
 	long timeout;
 
 	/* Catch invalid receive requests */
@@ -1336,8 +1695,8 @@ static int tipc_recvmsg(struct socket *sock, struct msghdr *m,
 	}
 	timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
 
+	/* Step rcv queue to first msg with data or error; wait if necessary */
 	do {
-		/* Look at first msg in receive queue; wait if necessary */
 		rc = tipc_wait_for_rcvmsg(sock, &timeout);
 		if (unlikely(rc))
 			goto exit;
@@ -1346,13 +1705,14 @@ static int tipc_recvmsg(struct socket *sock, struct msghdr *m,
 		dlen = msg_data_sz(hdr);
 		hlen = msg_hdr_sz(hdr);
 		err = msg_errcode(hdr);
+		grp_evt = msg_is_grp_evt(hdr);
 		if (likely(dlen || err))
 			break;
 		tsk_advance_rx_queue(sk);
 	} while (1);
 
 	/* Collect msg meta data, including error code and rejected data */
-	set_orig_addr(m, hdr);
+	tipc_sk_set_orig_addr(m, skb);
 	rc = tipc_sk_anc_data_recv(m, hdr, tsk);
 	if (unlikely(rc))
 		goto exit;
@@ -1372,15 +1732,33 @@ static int tipc_recvmsg(struct socket *sock, struct msghdr *m,
 	if (unlikely(rc))
 		goto exit;
 
+	/* Mark message as group event if applicable */
+	if (unlikely(grp_evt)) {
+		if (msg_grp_evt(hdr) == TIPC_WITHDRAWN)
+			m->msg_flags |= MSG_EOR;
+		m->msg_flags |= MSG_OOB;
+		copy = 0;
+	}
+
 	/* Caption of data or error code/rejected data was successful */
 	if (unlikely(flags & MSG_PEEK))
 		goto exit;
 
+	/* Send group flow control advertisement when applicable */
+	if (tsk->group && msg_in_group(hdr) && !grp_evt) {
+		skb_queue_head_init(&xmitq);
+		tipc_group_update_rcv_win(tsk->group, tsk_blocks(hlen + dlen),
+					  msg_orignode(hdr), msg_origport(hdr),
+					  &xmitq);
+		tipc_node_distr_xmit(sock_net(sk), &xmitq);
+	}
+
 	tsk_advance_rx_queue(sk);
+
 	if (likely(!connected))
 		goto exit;
 
-	/* Send connection flow control ack when applicable */
+	/* Send connection flow control advertisement when applicable */
 	tsk->rcv_unacked += tsk_inc(tsk, hlen + dlen);
 	if (tsk->rcv_unacked >= tsk->rcv_win / TIPC_ACK_RATE)
 		tipc_sk_send_ack(tsk);
@@ -1446,7 +1824,7 @@ static int tipc_recvstream(struct socket *sock, struct msghdr *m,
 
 		/* Collect msg meta data, incl. error code and rejected data */
 		if (!copied) {
-			set_orig_addr(m, hdr);
+			tipc_sk_set_orig_addr(m, skb);
 			rc = tipc_sk_anc_data_recv(m, hdr, tsk);
 			if (rc)
 				break;
@@ -1532,14 +1910,51 @@ static void tipc_sock_destruct(struct sock *sk)
 	__skb_queue_purge(&sk->sk_receive_queue);
 }
 
+static void tipc_sk_proto_rcv(struct sock *sk,
+			      struct sk_buff_head *inputq,
+			      struct sk_buff_head *xmitq)
+{
+	struct sk_buff *skb = __skb_dequeue(inputq);
+	struct tipc_sock *tsk = tipc_sk(sk);
+	struct tipc_msg *hdr = buf_msg(skb);
+	struct tipc_group *grp = tsk->group;
+	bool wakeup = false;
+
+	switch (msg_user(hdr)) {
+	case CONN_MANAGER:
+		tipc_sk_conn_proto_rcv(tsk, skb, xmitq);
+		return;
+	case SOCK_WAKEUP:
+		tipc_dest_del(&tsk->cong_links, msg_orignode(hdr), 0);
+		tsk->cong_link_cnt--;
+		wakeup = true;
+		break;
+	case GROUP_PROTOCOL:
+		tipc_group_proto_rcv(grp, &wakeup, hdr, inputq, xmitq);
+		break;
+	case TOP_SRV:
+		tipc_group_member_evt(tsk->group, &wakeup, &sk->sk_rcvbuf,
+				      skb, inputq, xmitq);
+		skb = NULL;
+		break;
+	default:
+		break;
+	}
+
+	if (wakeup)
+		sk->sk_write_space(sk);
+
+	kfree_skb(skb);
+}
+
 /**
- * filter_connect - Handle all incoming messages for a connection-based socket
+ * tipc_filter_connect - Handle incoming message for a connection-based socket
  * @tsk: TIPC socket
  * @skb: pointer to message buffer. Set to NULL if buffer is consumed
  *
  * Returns true if everything ok, false otherwise
  */
-static bool filter_connect(struct tipc_sock *tsk, struct sk_buff *skb)
+static bool tipc_sk_filter_connect(struct tipc_sock *tsk, struct sk_buff *skb)
 {
 	struct sock *sk = &tsk->sk;
 	struct net *net = sock_net(sk);
@@ -1643,6 +2058,9 @@ static unsigned int rcvbuf_limit(struct sock *sk, struct sk_buff *skb)
 	struct tipc_sock *tsk = tipc_sk(sk);
 	struct tipc_msg *hdr = buf_msg(skb);
 
+	if (unlikely(msg_in_group(hdr)))
+		return sk->sk_rcvbuf;
+
 	if (unlikely(!msg_connected(hdr)))
 		return sk->sk_rcvbuf << msg_importance(hdr);
 
@@ -1653,7 +2071,7 @@ static unsigned int rcvbuf_limit(struct sock *sk, struct sk_buff *skb)
 }
 
 /**
- * filter_rcv - validate incoming message
+ * tipc_sk_filter_rcv - validate incoming message
  * @sk: socket
  * @skb: pointer to message.
  *
@@ -1662,99 +2080,71 @@ static unsigned int rcvbuf_limit(struct sock *sk, struct sk_buff *skb)
  *
  * Called with socket lock already taken
  *
- * Returns true if message was added to socket receive queue, otherwise false
  */
-static bool filter_rcv(struct sock *sk, struct sk_buff *skb,
+static void tipc_sk_filter_rcv(struct sock *sk, struct sk_buff *skb,
 			       struct sk_buff_head *xmitq)
 {
+	bool sk_conn = !tipc_sk_type_connectionless(sk);
 	struct tipc_sock *tsk = tipc_sk(sk);
+	struct tipc_group *grp = tsk->group;
 	struct tipc_msg *hdr = buf_msg(skb);
-	unsigned int limit = rcvbuf_limit(sk, skb);
-	int err = TIPC_OK;
-	int usr = msg_user(hdr);
-	u32 onode;
+	struct net *net = sock_net(sk);
+	struct sk_buff_head inputq;
+	int limit, err = TIPC_OK;
 
-	if (unlikely(msg_user(hdr) == CONN_MANAGER)) {
-		tipc_sk_proto_rcv(tsk, skb, xmitq);
-		return false;
-	}
+	TIPC_SKB_CB(skb)->bytes_read = 0;
+	__skb_queue_head_init(&inputq);
+	__skb_queue_tail(&inputq, skb);
 
-	if (unlikely(usr == SOCK_WAKEUP)) {
-		onode = msg_orignode(hdr);
-		kfree_skb(skb);
-		u32_del(&tsk->cong_links, onode);
-		tsk->cong_link_cnt--;
-		sk->sk_write_space(sk);
-		return false;
-	}
+	if (unlikely(!msg_isdata(hdr)))
+		tipc_sk_proto_rcv(sk, &inputq, xmitq);
 
-	/* Drop if illegal message type */
-	if (unlikely(msg_type(hdr) > TIPC_DIRECT_MSG)) {
-		kfree_skb(skb);
-		return false;
-	}
+	if (unlikely(grp))
+		tipc_group_filter_msg(grp, &inputq, xmitq);
 
-	/* Reject if wrong message type for current socket state */
-	if (tipc_sk_type_connectionless(sk)) {
-		if (msg_connected(hdr)) {
-			err = TIPC_ERR_NO_PORT;
-			goto reject;
-		}
-	} else if (unlikely(!filter_connect(tsk, skb))) {
+	/* Validate and add to receive buffer if there is space */
+	while ((skb = __skb_dequeue(&inputq))) {
+		hdr = buf_msg(skb);
+		limit = rcvbuf_limit(sk, skb);
+		if ((sk_conn && !tipc_sk_filter_connect(tsk, skb)) ||
+		    (!sk_conn && msg_connected(hdr)) ||
+		    (!grp && msg_in_group(hdr)))
 			err = TIPC_ERR_NO_PORT;
-		goto reject;
-	}
-
-	/* Reject message if there isn't room to queue it */
-	if (unlikely(sk_rmem_alloc_get(sk) + skb->truesize >= limit)) {
+		else if (sk_rmem_alloc_get(sk) + skb->truesize >= limit)
 			err = TIPC_ERR_OVERLOAD;
-		goto reject;
-	}
 
-	/* Enqueue message */
-	TIPC_SKB_CB(skb)->bytes_read = 0;
+		if (unlikely(err)) {
+			tipc_skb_reject(net, err, skb, xmitq);
+			err = TIPC_OK;
+			continue;
+		}
 		__skb_queue_tail(&sk->sk_receive_queue, skb);
 		skb_set_owner_r(skb, sk);
-
 		sk->sk_data_ready(sk);
-	return true;
-
-reject:
-	if (tipc_msg_reverse(tsk_own_node(tsk), &skb, err))
-		__skb_queue_tail(xmitq, skb);
-	return false;
+	}
 }
 
 /**
- * tipc_backlog_rcv - handle incoming message from backlog queue
+ * tipc_sk_backlog_rcv - handle incoming message from backlog queue
  * @sk: socket
  * @skb: message
  *
  * Caller must hold socket lock
- *
- * Returns 0
  */
-static int tipc_backlog_rcv(struct sock *sk, struct sk_buff *skb)
+static int tipc_sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
 {
-	unsigned int truesize = skb->truesize;
+	unsigned int before = sk_rmem_alloc_get(sk);
 	struct sk_buff_head xmitq;
-	u32 dnode, selector;
+	unsigned int added;
 
 	__skb_queue_head_init(&xmitq);
 
-	if (likely(filter_rcv(sk, skb, &xmitq))) {
-		atomic_add(truesize, &tipc_sk(sk)->dupl_rcvcnt);
-		return 0;
-	}
+	tipc_sk_filter_rcv(sk, skb, &xmitq);
+	added = sk_rmem_alloc_get(sk) - before;
+	atomic_add(added, &tipc_sk(sk)->dupl_rcvcnt);
 
-	if (skb_queue_empty(&xmitq))
-		return 0;
-
-	/* Send response/rejected message */
-	skb = __skb_dequeue(&xmitq);
-	dnode = msg_destnode(buf_msg(skb));
-	selector = msg_origport(buf_msg(skb));
-	tipc_node_xmit_skb(sock_net(sk), skb, dnode, selector);
+	/* Send pending response/rejected messages, if any */
+	tipc_node_distr_xmit(sock_net(sk), &xmitq);
 	return 0;
 }
 
@@ -1786,7 +2176,7 @@ static void tipc_sk_enqueue(struct sk_buff_head *inputq, struct sock *sk,
 
 		/* Add message directly to receive queue if possible */
 		if (!sock_owned_by_user(sk)) {
-			filter_rcv(sk, skb, xmitq);
+			tipc_sk_filter_rcv(sk, skb, xmitq);
 			continue;
 		}
 
@@ -1833,14 +2223,10 @@ void tipc_sk_rcv(struct net *net, struct sk_buff_head *inputq)
 				spin_unlock_bh(&sk->sk_lock.slock);
 			}
 			/* Send pending response/rejected messages, if any */
-			while ((skb = __skb_dequeue(&xmitq))) {
-				dnode = msg_destnode(buf_msg(skb));
-				tipc_node_xmit_skb(net, skb, dnode, dport);
-			}
+			tipc_node_distr_xmit(sock_net(sk), &xmitq);
 			sock_put(sk);
 			continue;
 		}
-
 		/* No destination socket => dequeue skb if still there */
 		skb = tipc_skb_dequeue(inputq, dport);
 		if (!skb)
@@ -1903,28 +2289,32 @@ static int tipc_connect(struct socket *sock, struct sockaddr *dest,
 	int previous;
 	int res = 0;
 
+	if (destlen != sizeof(struct sockaddr_tipc))
+		return -EINVAL;
+
 	lock_sock(sk);
 
-	/* DGRAM/RDM connect(), just save the destaddr */
-	if (tipc_sk_type_connectionless(sk)) {
+	if (tsk->group) {
+		res = -EINVAL;
+		goto exit;
+	}
+
 	if (dst->family == AF_UNSPEC) {
 		memset(&tsk->peer, 0, sizeof(struct sockaddr_tipc));
-		} else if (destlen != sizeof(struct sockaddr_tipc)) {
+		if (!tipc_sk_type_connectionless(sk))
 			res = -EINVAL;
-		} else {
-			memcpy(&tsk->peer, dest, destlen);
-		}
 		goto exit;
+	} else if (dst->family != AF_TIPC) {
+		res = -EINVAL;
 	}
-
-	/*
-	 * Reject connection attempt using multicast address
-	 *
-	 * Note: send_msg() validates the rest of the address fields,
-	 *       so there's no need to do it here
-	 */
-	if (dst->addrtype == TIPC_ADDR_MCAST) {
+	if (dst->addrtype != TIPC_ADDR_ID && dst->addrtype != TIPC_ADDR_NAME)
 		res = -EINVAL;
+	if (res)
+		goto exit;
+
+	/* DGRAM/RDM connect(), just save the destaddr */
+	if (tipc_sk_type_connectionless(sk)) {
+		memcpy(&tsk->peer, dest, destlen);
 		goto exit;
 	}
 
@@ -2345,6 +2735,56 @@ void tipc_sk_rht_destroy(struct net *net)
 	rhashtable_destroy(&tn->sk_rht);
 }
 
+static int tipc_sk_join(struct tipc_sock *tsk, struct tipc_group_req *mreq)
+{
+	struct net *net = sock_net(&tsk->sk);
+	u32 domain = addr_domain(net, mreq->scope);
+	struct tipc_group *grp = tsk->group;
+	struct tipc_msg *hdr = &tsk->phdr;
+	struct tipc_name_seq seq;
+	int rc;
+
+	if (mreq->type < TIPC_RESERVED_TYPES)
+		return -EACCES;
+	if (grp)
+		return -EACCES;
+	grp = tipc_group_create(net, tsk->portid, mreq);
+	if (!grp)
+		return -ENOMEM;
+	tsk->group = grp;
+	msg_set_lookup_scope(hdr, mreq->scope);
+	msg_set_nametype(hdr, mreq->type);
+	msg_set_dest_droppable(hdr, true);
+	seq.type = mreq->type;
+	seq.lower = mreq->instance;
+	seq.upper = seq.lower;
+	tipc_nametbl_build_group(net, grp, mreq->type, domain);
+	rc = tipc_sk_publish(tsk, mreq->scope, &seq);
+	if (rc)
+		tipc_group_delete(net, grp);
+
+	/* Eliminate any risk that a broadcast overtakes the sent JOIN */
+	tsk->mc_method.rcast = true;
+	tsk->mc_method.mandatory = true;
+	return rc;
+}
+
+static int tipc_sk_leave(struct tipc_sock *tsk)
+{
+	struct net *net = sock_net(&tsk->sk);
+	struct tipc_group *grp = tsk->group;
+	struct tipc_name_seq seq;
+	int scope;
+
+	if (!grp)
+		return -EINVAL;
+	tipc_group_self(grp, &seq, &scope);
+	tipc_group_delete(net, grp);
+	tsk->group = NULL;
+	tipc_sk_withdraw(tsk, scope, &seq);
+	return 0;
+}
+
 /**
  * tipc_setsockopt - set socket option
  * @sock: socket structure
@@ -2363,6 +2803,7 @@ static int tipc_setsockopt(struct socket *sock, int lvl, int opt,
 {
 	struct sock *sk = sock->sk;
 	struct tipc_sock *tsk = tipc_sk(sk);
+	struct tipc_group_req mreq;
 	u32 value = 0;
 	int res = 0;
 
@@ -2378,9 +2819,14 @@ static int tipc_setsockopt(struct socket *sock, int lvl, int opt,
 	case TIPC_CONN_TIMEOUT:
 		if (ol < sizeof(value))
 			return -EINVAL;
-		res = get_user(value, (u32 __user *)ov);
-		if (res)
-			return res;
+		if (get_user(value, (u32 __user *)ov))
+			return -EFAULT;
+		break;
+	case TIPC_GROUP_JOIN:
+		if (ol < sizeof(mreq))
+			return -EINVAL;
+		if (copy_from_user(&mreq, ov, sizeof(mreq)))
+			return -EFAULT;
 		break;
 	default:
 		if (ov || ol)
@@ -2413,6 +2859,12 @@ static int tipc_setsockopt(struct socket *sock, int lvl, int opt,
 		tsk->mc_method.rcast = true;
 		tsk->mc_method.mandatory = true;
 		break;
+	case TIPC_GROUP_JOIN:
+		res = tipc_sk_join(tsk, &mreq);
+		break;
+	case TIPC_GROUP_LEAVE:
+		res = tipc_sk_leave(tsk);
+		break;
 	default:
 		res = -EINVAL;
 	}
@@ -2440,7 +2892,8 @@ static int tipc_getsockopt(struct socket *sock, int lvl, int opt,
 {
 	struct sock *sk = sock->sk;
 	struct tipc_sock *tsk = tipc_sk(sk);
-	int len;
+	struct tipc_name_seq seq;
+	int len, scope;
 	u32 value;
 	int res;
 
@@ -2474,6 +2927,12 @@ static int tipc_getsockopt(struct socket *sock, int lvl, int opt,
 	case TIPC_SOCK_RECVQ_DEPTH:
 		value = skb_queue_len(&sk->sk_receive_queue);
 		break;
+	case TIPC_GROUP_JOIN:
+		seq.type = 0;
+		if (tsk->group)
+			tipc_group_self(tsk->group, &seq, &scope);
+		value = seq.type;
+		break;
 	default:
 		res = -EINVAL;
 	}