linux/net/tipc/name_table.h
Hoang Huu Le cad2929dc4 tipc: update a binding service via broadcast
Currently, updating binding table (add service binding to
name table/withdraw a service binding) is being sent over replicast.
However, if we are scaling up clusters to > 100 nodes/containers this
method is less affection because of looping through nodes in a cluster one
by one.

It is worth to use broadcast to update a binding service. This way, the
binding table can be updated on all peer nodes in one shot.

Broadcast is used when all peer nodes, as indicated by a new capability
flag TIPC_NAMED_BCAST, support reception of this message type.

Four problems need to be considered when introducing this feature.
1) When establishing a link to a new peer node we still update this by a
unicast 'bulk' update. This may lead to race conditions, where a later
broadcast publication/withdrawal bypass the 'bulk', resulting in
disordered publications, or even that a withdrawal may arrive before the
corresponding publication. We solve this by adding an 'is_last_bulk' bit
in the last bulk messages so that it can be distinguished from all other
messages. Only when this message has arrived do we open up for reception
of broadcast publications/withdrawals.

2) When a first legacy node is added to the cluster all distribution
will switch over to use the legacy 'replicast' method, while the
opposite happens when the last legacy node leaves the cluster. This
entails another risk of message disordering that has to be handled. We
solve this by adding a sequence number to the broadcast/replicast
messages, so that disordering can be discovered and corrected. Note
however that we don't need to consider potential message loss or
duplication at this protocol level.

3) Bulk messages don't contain any sequence numbers, and will always
arrive in order. Hence we must exempt those from the sequence number
control and deliver them unconditionally. We solve this by adding a new
'is_bulk' bit in those messages so that they can be recognized.

4) Legacy messages, which don't contain any new bits or sequence
numbers, but neither can arrive out of order, also need to be exempt
from the initial synchronization and sequence number check, and
delivered unconditionally. Therefore, we add another 'is_not_legacy' bit
to all new messages so that those can be distinguished from legacy
messages and the latter delivered directly.

v1->v2:
 - fix warning issue reported by kbuild test robot <lkp@intel.com>
 - add santiy check to drop the publication message with a sequence
number that is lower than the agreed synch point

Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Hoang Huu Le <hoang.h.le@dektech.com.au>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-17 08:53:34 -07:00

155 lines
6.2 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
* 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;
/*
* 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 */
/**
* struct publication - info about a published (name or) name sequence
* @type: name sequence type
* @lower: name sequence lower bound
* @upper: name sequence upper bound
* @scope: scope of publication, TIPC_NODE_SCOPE or TIPC_CLUSTER_SCOPE
* @node: network address of publishing socket's node
* @port: publishing port
* @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 {
u32 type;
u32 lower;
u32 upper;
u32 scope;
u32 node;
u32 port;
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
* @seq_hlist: 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
* @local_publ_count: number of publications issued by this node
*/
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);
u32 tipc_nametbl_translate(struct net *net, u32 type, u32 instance, u32 *node);
void tipc_nametbl_mc_lookup(struct net *net, u32 type, u32 lower, u32 upper,
u32 scope, bool exact, 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, 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,
u32 key);
int tipc_nametbl_withdraw(struct net *net, u32 type, u32 lower, u32 upper,
u32 key);
struct publication *tipc_nametbl_insert_publ(struct net *net, u32 type,
u32 lower, u32 upper, u32 scope,
u32 node, u32 ref, u32 key);
struct publication *tipc_nametbl_remove_publ(struct net *net, u32 type,
u32 lower, u32 upper,
u32 node, 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