tipc: introduce communication groups

As a preparation for introducing flow control for multicast and datagram
messaging we need a more strictly defined framework than we have now. A
socket must be able keep track of exactly how many and which other
sockets it is allowed to communicate with at any moment, and keep the
necessary state for those.

We therefore introduce a new concept we have named Communication Group.
Sockets can join a group via a new setsockopt() call TIPC_GROUP_JOIN.
The call takes four parameters: 'type' serves as group identifier,
'instance' serves as an logical member identifier, and 'scope' indicates
the visibility of the group (node/cluster/zone). Finally, 'flags' makes
it possible to set certain properties for the member. For now, there is
only one flag, indicating if the creator of the socket wants to receive
a copy of broadcast or multicast messages it is sending via the socket,
and if wants to be eligible as destination for its own anycasts.

A group is 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.

Any member of a group can send multicast ('group broadcast') messages
to all group members, optionally including itself, using the primitive
send(). The messages are received via the recvmsg() primitive. A socket
can only be member of one group at a time.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

9 files changed, 734 insertions, 48 deletions

diff --git a/net/tipc/Makefile b/net/tipc/Makefile
index 31b9f9c52974..a3af73ec0b78 100644
--- a/net/tipc/Makefile
+++ b/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
diff --git a/net/tipc/group.c b/net/tipc/group.c
new file mode 100644
index 000000000000..3f0e1ce1e3b9
--- /dev/null
+++ b/net/tipc/group.c
@@ -0,0 +1,404 @@
+/*
+ * 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
+
+enum mbr_state {
+        MBR_QUARANTINED,
+        MBR_DISCOVERED,
+        MBR_JOINING,
+        MBR_PUBLISHED,
+        MBR_JOINED,
+        MBR_LEAVING
+};
+
+struct tipc_member {
+        struct rb_node tree_node;
+        struct list_head list;
+        u32 node;
+        u32 port;
+        enum mbr_state state;
+        u16 bc_rcv_nxt;
+};
+
+struct tipc_group {
+        struct rb_root members;
+        struct tipc_nlist dests;
+        struct net *net;
+        int subid;
+        u32 type;
+        u32 instance;
+        u32 domain;
+        u32 scope;
+        u32 portid;
+        u16 member_cnt;
+        u16 bc_snd_nxt;
+        bool loopback;
+};
+
+static void tipc_group_proto_xmit(struct tipc_group *grp, struct tipc_member *m,
+                                  int mtyp, struct sk_buff_head *xmitq);
+
+u16 tipc_group_bc_snd_nxt(struct tipc_group *grp)
+{
+        return grp->bc_snd_nxt;
+}
+
+static bool tipc_group_is_receiver(struct tipc_member *m)
+{
+        return m && m->state >= MBR_JOINED;
+}
+
+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));
+        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;
+        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_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);
+        m->node = node;
+        m->port = port;
+        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--;
+        list_del_init(&m->list);
+
+        /* 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_bc_members(struct tipc_group *grp)
+{
+        grp->bc_snd_nxt++;
+}
+
+/* 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);
+        struct tipc_member *m;
+        struct tipc_msg *hdr;
+        u32 node, port;
+        int mtyp;
+
+        if (!skb)
+                return;
+
+        hdr = buf_msg(skb);
+        mtyp = msg_type(hdr);
+        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;
+
+        __skb_queue_tail(inputq, skb);
+
+        m->bc_rcv_nxt = msg_grp_bc_seqno(hdr) + 1;
+        return;
+drop:
+        kfree_skb(skb);
+}
+
+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;
+
+        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;
+
+        hdr = buf_msg(skb);
+        if (mtyp == GRP_JOIN_MSG)
+                msg_set_grp_bc_syncpt(hdr, grp->bc_snd_nxt);
+        __skb_queue_tail(xmitq, skb);
+}
+
+void tipc_group_proto_rcv(struct tipc_group *grp, struct tipc_msg *hdr,
+                          struct sk_buff_head *xmitq)
+{
+        u32 node = msg_orignode(hdr);
+        u32 port = msg_origport(hdr);
+        struct tipc_member *m;
+
+        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_rcv_nxt = msg_grp_bc_syncpt(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;
+                return;
+        case GRP_LEAVE_MSG:
+                if (!m)
+                        return;
+
+                /* Wait until WITHDRAW event is received */
+                if (m->state != MBR_LEAVING) {
+                        m->state = MBR_LEAVING;
+                        return;
+                }
+                /* Otherwise deliver already received WITHDRAW event */
+                tipc_group_delete_member(grp, m);
+                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,
+                           struct sk_buff *skb,
+                           struct sk_buff_head *xmitq)
+{
+        struct tipc_msg *hdr = buf_msg(skb);
+        struct tipc_event *evt = (void *)msg_data(hdr);
+        u32 node = evt->port.node;
+        u32 port = evt->port.ref;
+        struct tipc_member *m;
+        struct net *net;
+        u32 self;
+
+        if (!grp)
+                goto drop;
+
+        net = grp->net;
+        self = tipc_own_addr(net);
+        if (!grp->loopback && node == self && port == grp->portid)
+                goto drop;
+
+        m = tipc_group_find_member(grp, node, port);
+
+        if (evt->event == TIPC_PUBLISHED) {
+                if (!m)
+                        m = tipc_group_create_member(grp, node, port,
+                                                     MBR_DISCOVERED);
+                if (!m)
+                        goto drop;
+
+                /* Wait if JOIN message not yet received */
+                if (m->state == MBR_DISCOVERED)
+                        m->state = MBR_PUBLISHED;
+                else
+                        m->state = MBR_JOINED;
+                tipc_group_proto_xmit(grp, m, GRP_JOIN_MSG, xmitq);
+        } else if (evt->event == TIPC_WITHDRAWN) {
+                if (!m)
+                        goto drop;
+
+                /* Keep back event if more messages might be expected */
+                if (m->state != MBR_LEAVING && tipc_node_is_up(net, node))
+                        m->state = MBR_LEAVING;
+                else
+                        tipc_group_delete_member(grp, m);
+        }
+drop:
+        kfree_skb(skb);
+}
diff --git a/net/tipc/group.h b/net/tipc/group.h
new file mode 100644
index 000000000000..9bdf4479fc03
--- /dev/null
+++ b/net/tipc/group.h
@@ -0,0 +1,64 @@
+/*
+ * 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);
+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,
+                           struct sk_buff *skb,
+                           struct sk_buff_head *xmitq);
+void tipc_group_proto_rcv(struct tipc_group *grp,
+                          struct tipc_msg *hdr,
+                          struct sk_buff_head *xmitq);
+void tipc_group_update_bc_members(struct tipc_group *grp);
+u16 tipc_group_bc_snd_nxt(struct tipc_group *grp);
+int tipc_group_size(struct tipc_group *grp);
+#endif
diff --git a/net/tipc/link.c b/net/tipc/link.c
index ac0144f532aa..bd25bff63925 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1046,11 +1046,12 @@ 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)) {
+                if (unlikely(msg_mcast(hdr))) {
                         skb_queue_tail(l->bc_rcvlink->inputq, skb);
                         return true;
                 }
         case CONN_MANAGER:
+        case GROUP_PROTOCOL:
                 skb_queue_tail(inputq, skb);
                 return true;
         case NAME_DISTRIBUTOR:
diff --git a/net/tipc/msg.h b/net/tipc/msg.h
index be3e38aa9dd2..dad400935405 100644
--- a/net/tipc/msg.h
+++ b/net/tipc/msg.h
@@ -1,7 +1,7 @@
 /*
  * 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.
  *
@@ -61,10 +61,11 @@ struct plist;
 /*
  * Payload message types
  */
-#define TIPC_CONN_MSG           0
-#define TIPC_MCAST_MSG          1
-#define TIPC_NAMED_MSG          2
-#define TIPC_DIRECT_MSG         3
+#define TIPC_CONN_MSG           0
+#define TIPC_MCAST_MSG          1
+#define TIPC_NAMED_MSG          2
+#define TIPC_DIRECT_MSG         3
+#define TIPC_GRP_BCAST_MSG      4
 
 /*
  * Internal message users
@@ -73,6 +74,7 @@ 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
@@ -87,6 +89,7 @@ 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 */
@@ -252,6 +255,11 @@ 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)
+{
+        return (msg_type(m) == TIPC_GRP_BCAST_MSG);
+}
+
 static inline u32 msg_named(struct tipc_msg *m)
 {
         return msg_type(m) == TIPC_NAMED_MSG;
@@ -259,7 +267,9 @@ 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));
 }
 
 static inline u32 msg_connected(struct tipc_msg *m)
@@ -515,6 +525,12 @@ static inline void msg_set_nameupper(struct tipc_msg *m, u32 n)
 #define DSC_RESP_MSG            1
 
 /*
+ * Group protocol message types
+ */
+#define GRP_JOIN_MSG         0
+#define GRP_LEAVE_MSG        1
+
+/*
  * Word 1
  */
 static inline u32 msg_seq_gap(struct tipc_msg *m)
@@ -795,6 +811,28 @@ 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);
+}
+
+/* Word 10
+ */
+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))
diff --git a/net/tipc/name_table.c b/net/tipc/name_table.c
index 76bd2777baaf..114d72bab827 100644
--- a/net/tipc/name_table.c
+++ b/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 +597,6 @@ not_found:
         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
- */
 int tipc_nametbl_mc_translate(struct net *net, u32 type, u32 lower, u32 upper,
                               u32 limit, struct list_head *dports)
 {
@@ -679,6 +668,37 @@ exit:
         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
  */
diff --git a/net/tipc/name_table.h b/net/tipc/name_table.h
index d121175a92b5..97646b17a4a2 100644
--- a/net/tipc/name_table.h
+++ b/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)
@@ -101,6 +102,8 @@ 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);
diff --git a/net/tipc/node.h b/net/tipc/node.h
index df2f2197c4ad..acd58d23a70e 100644
--- a/net/tipc/node.h
+++ b/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 | \
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index daf7c4df4531..64bbf9d03629 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -1,7 +1,7 @@
 /*
  * 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 */
@@ -78,7 +79,7 @@ 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
@@ -109,6 +110,7 @@ struct tipc_sock {
         struct rhash_head node;
         struct tipc_mc_method mc_method;
         struct rcu_head rcu;
+        struct tipc_group *group;
 };
 
 static int tipc_sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
@@ -123,6 +125,7 @@ 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);
@@ -559,6 +562,7 @@ 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);
@@ -601,7 +605,10 @@ 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;
@@ -698,6 +705,7 @@ static unsigned int tipc_poll(struct file *file, struct socket *sock,
 {
         struct sock *sk = sock->sk;
         struct tipc_sock *tsk = tipc_sk(sk);
+        struct tipc_group *grp = tsk->group;
         u32 mask = 0;
 
         sock_poll_wait(file, sk_sleep(sk), wait);
@@ -718,8 +726,9 @@ static unsigned int tipc_poll(struct file *file, struct socket *sock,
                         mask |= (POLLIN | POLLRDNORM);
                 break;
         case TIPC_OPEN:
-                if (!tsk->cong_link_cnt)
-                        mask |= POLLOUT;
+                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);
@@ -757,6 +766,9 @@ 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))
@@ -794,6 +806,64 @@ static int tipc_sendmcast(struct  socket *sock, struct tipc_name_seq *seq,
 }
 
 /**
+ * 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)
+{
+        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;
+        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 is congested */
+        rc = tipc_wait_for_cond(sock, &timeout, !tsk->cong_link_cnt);
+        if (unlikely(rc))
+                return rc;
+
+        /* Complete message header */
+        msg_set_type(hdr, TIPC_GRP_BCAST_MSG);
+        msg_set_hdr_sz(hdr, MCAST_H_SIZE);
+        msg_set_destport(hdr, 0);
+        msg_set_destnode(hdr, 0);
+        msg_set_nameinst(hdr, 0);
+        msg_set_grp_bc_seqno(hdr, tipc_group_bc_snd_nxt(grp));
+
+        /* 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 */
+        tipc_group_update_bc_members(tsk->group);
+
+        return dlen;
+}
+
+/**
  * tipc_sk_mcast_rcv - Deliver multicast messages to all destination sockets
  * @arrvq: queue with arriving messages, to be cloned after destination lookup
  * @inputq: queue with cloned messages, delivered to socket after dest lookup
@@ -803,13 +873,15 @@ 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 hsz;
 
         __skb_queue_head_init(&tmpq);
         INIT_LIST_HEAD(&dports);
@@ -818,14 +890,18 @@ void tipc_sk_mcast_rcv(struct net *net, struct sk_buff_head *arrvq,
         for (; skb; skb = tipc_skb_peek(arrvq, &inputq->lock)) {
                 msg = buf_msg(skb);
                 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);
+                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) {
@@ -895,10 +971,6 @@ exit:
         kfree_skb(skb);
 }
 
-static void tipc_sk_top_evt(struct tipc_sock *tsk, struct tipc_event *evt)
-{
-}
-
 /**
  * tipc_sendmsg - send message in connectionless manner
  * @sock: socket structure
@@ -934,6 +1006,7 @@ 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;
@@ -944,6 +1017,9 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dlen)
         if (unlikely(dlen > TIPC_MAX_USER_MSG_SIZE))
                 return -EMSGSIZE;
 
+        if (unlikely(grp))
+                return tipc_send_group_bcast(sock, m, dlen, timeout);
+
         if (unlikely(!dest)) {
                 dest = &tsk->peer;
                 if (!syn || dest->family != AF_TIPC)
@@ -1543,6 +1619,7 @@ static void tipc_sk_proto_rcv(struct sock *sk,
         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;
 
         switch (msg_user(hdr)) {
         case CONN_MANAGER:
@@ -1553,8 +1630,12 @@ static void tipc_sk_proto_rcv(struct sock *sk,
                 tsk->cong_link_cnt--;
                 sk->sk_write_space(sk);
                 break;
+        case GROUP_PROTOCOL:
+                tipc_group_proto_rcv(grp, hdr, xmitq);
+                break;
         case TOP_SRV:
-                tipc_sk_top_evt(tsk, (void *)msg_data(hdr));
+                tipc_group_member_evt(tsk->group, skb, xmitq);
+                skb = NULL;
                 break;
         default:
                 break;
@@ -1699,6 +1780,7 @@ static void tipc_sk_filter_rcv(struct sock *sk, struct sk_buff *skb,
 {
         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);
         struct net *net = sock_net(sk);
         struct sk_buff_head inputq;
@@ -1710,15 +1792,19 @@ static void tipc_sk_filter_rcv(struct sock *sk, struct sk_buff *skb,
 
         if (unlikely(!msg_isdata(hdr)))
                 tipc_sk_proto_rcv(sk, &inputq, xmitq);
-        else if (unlikely(msg_type(hdr) > TIPC_DIRECT_MSG))
+        else if (unlikely(msg_type(hdr) > TIPC_GRP_BCAST_MSG))
                 return kfree_skb(skb);
 
+        if (unlikely(grp))
+                tipc_group_filter_msg(grp, &inputq, xmitq);
+
         /* 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)))
+                    (!sk_conn && msg_connected(hdr)) ||
+                    (!grp && msg_in_group(hdr)))
                         err = TIPC_ERR_NO_PORT;
                 else if (sk_rmem_alloc_get(sk) + skb->truesize >= limit)
                         err = TIPC_ERR_OVERLOAD;
@@ -1837,7 +1923,6 @@ void tipc_sk_rcv(struct net *net, struct sk_buff_head *inputq)
                         sock_put(sk);
                         continue;
                 }
-
                 /* No destination socket => dequeue skb if still there */
                 skb = tipc_skb_dequeue(inputq, dport);
                 if (!skb)
@@ -1905,6 +1990,11 @@ static int tipc_connect(struct socket *sock, struct sockaddr *dest,
 
         lock_sock(sk);
 
+        if (tsk->group) {
+                res = -EINVAL;
+                goto exit;
+        }
+
         if (dst->family == AF_UNSPEC) {
                 memset(&tsk->peer, 0, sizeof(struct sockaddr_tipc));
                 if (!tipc_sk_type_connectionless(sk))
@@ -2341,6 +2431,52 @@ 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);
+        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
@@ -2359,6 +2495,7 @@ 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;
 
@@ -2374,9 +2511,14 @@ 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)
@@ -2409,6 +2551,12 @@ 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;
         }
@@ -2436,7 +2584,8 @@ 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;
 
@@ -2470,6 +2619,12 @@ 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;
         }