linux/net/tipc/name_table.h
Jon Maloy 5ef213258d tipc: simplify handling of lookup scope during multicast message reception
We introduce a new macro TIPC_ANY_SCOPE to make the handling of the
lookup scope value more comprehensible during multicast reception.

The (unchanged) rules go as follows:

1) Multicast messages sent from own node are delivered to all matching
   sockets on the own node, irrespective of their binding scope.

2) Multicast messages sent from other nodes arrive here because they
   have found TIPC_CLUSTER_SCOPE bindings emanating from this node.
   Those messages should be delivered to exactly those sockets, but not
   to local sockets bound with TIPC_NODE_SCOPE, since the latter
   obviously were not meant to be visible for those senders.

3) Group multicast/broadcast messages are delivered to the sockets with
   a binding scope matching exactly the lookup scope indicated in the
   message header, and nobody else.

Reviewed-by: Xin Long <lucien.xin@gmail.com>
Tested-by: Hoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-03 14:06:39 -07:00

157 lines
6.5 KiB
C

/*
* net/tipc/name_table.h: Include file for TIPC name table code
*
* Copyright (c) 2000-2006, 2014-2018, Ericsson AB
* Copyright (c) 2004-2005, 2010-2011, Wind River Systems
* Copyright (c) 2020-2021, Red Hat Inc
* 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_NAME_TABLE_H
#define _TIPC_NAME_TABLE_H
struct tipc_subscription;
struct tipc_plist;
struct tipc_nlist;
struct tipc_group;
struct tipc_uaddr;
/*
* TIPC name types reserved for internal TIPC use (both current and planned)
*/
#define TIPC_ZM_SRV 3 /* zone master service name type */
#define TIPC_PUBL_SCOPE_NUM (TIPC_NODE_SCOPE + 1)
#define TIPC_NAMETBL_SIZE 1024 /* must be a power of 2 */
#define TIPC_ANY_SCOPE 10 /* Both node and cluster scope will match */
/**
* struct publication - info about a published service address or range
* @sr: service range represented by this publication
* @sk: address of socket bound to this publication
* @scope: scope of publication, TIPC_NODE_SCOPE or TIPC_CLUSTER_SCOPE
* @key: publication key, unique across the cluster
* @id: publication id
* @binding_node: all publications from the same node which bound this one
* - Remote publications: in node->publ_list;
* Used by node/name distr to withdraw publications when node is lost
* - Local/node scope publications: in name_table->node_scope list
* - Local/cluster scope publications: in name_table->cluster_scope list
* @binding_sock: all publications from the same socket which bound this one
* Used by socket to withdraw publications when socket is unbound/released
* @local_publ: list of identical publications made from this node
* Used by closest_first and multicast receive lookup algorithms
* @all_publ: all publications identical to this one, whatever node and scope
* Used by round-robin lookup algorithm
* @list: to form a list of publications in temporal order
* @rcu: RCU callback head used for deferred freeing
*/
struct publication {
struct tipc_service_range sr;
struct tipc_socket_addr sk;
u16 scope;
u32 key;
u32 id;
struct list_head binding_node;
struct list_head binding_sock;
struct list_head local_publ;
struct list_head all_publ;
struct list_head list;
struct rcu_head rcu;
};
/**
* struct name_table - table containing all existing port name publications
* @services: name sequence hash lists
* @node_scope: all local publications with node scope
* - used by name_distr during re-init of name table
* @cluster_scope: all local publications with cluster scope
* - used by name_distr to send bulk updates to new nodes
* - used by name_distr during re-init of name table
* @cluster_scope_lock: lock for accessing @cluster_scope
* @local_publ_count: number of publications issued by this node
* @rc_dests: destination node counter
* @snd_nxt: next sequence number to be used
*/
struct name_table {
struct hlist_head services[TIPC_NAMETBL_SIZE];
struct list_head node_scope;
struct list_head cluster_scope;
rwlock_t cluster_scope_lock;
u32 local_publ_count;
u32 rc_dests;
u32 snd_nxt;
};
int tipc_nl_name_table_dump(struct sk_buff *skb, struct netlink_callback *cb);
bool tipc_nametbl_lookup_anycast(struct net *net, struct tipc_uaddr *ua,
struct tipc_socket_addr *sk);
void tipc_nametbl_lookup_mcast_sockets(struct net *net, struct tipc_uaddr *ua,
struct list_head *dports);
void tipc_nametbl_lookup_mcast_nodes(struct net *net, struct tipc_uaddr *ua,
struct tipc_nlist *nodes);
bool tipc_nametbl_lookup_group(struct net *net, struct tipc_uaddr *ua,
struct list_head *dsts, int *dstcnt,
u32 exclude, bool mcast);
void tipc_nametbl_build_group(struct net *net, struct tipc_group *grp,
struct tipc_uaddr *ua);
struct publication *tipc_nametbl_publish(struct net *net, struct tipc_uaddr *ua,
struct tipc_socket_addr *sk, u32 key);
void tipc_nametbl_withdraw(struct net *net, struct tipc_uaddr *ua,
struct tipc_socket_addr *sk, u32 key);
struct publication *tipc_nametbl_insert_publ(struct net *net,
struct tipc_uaddr *ua,
struct tipc_socket_addr *sk,
u32 key);
struct publication *tipc_nametbl_remove_publ(struct net *net,
struct tipc_uaddr *ua,
struct tipc_socket_addr *sk,
u32 key);
bool tipc_nametbl_subscribe(struct tipc_subscription *s);
void tipc_nametbl_unsubscribe(struct tipc_subscription *s);
int tipc_nametbl_init(struct net *net);
void tipc_nametbl_stop(struct net *net);
struct tipc_dest {
struct list_head list;
u32 port;
u32 node;
};
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