linux/net/tipc/node_subscr.c
Allan Stephens f0712e86b7 tipc: Ensure network address change doesn't impact local connections
Revises routines that deal with connections between two ports on
the same node to ensure the connection is not impacted if the node's
network address is changed in mid-operation. The routines now treat
the default node address of <0.0.0> as an alias for "this node" in
the following situations:

1) Incoming messages destined to a connected port now handle the alias
properly when validating that the message was sent by the expected
peer port, ensuring that the message will be accepted regardless of
whether it specifies the node's old network address or it's current one.

2) The code which completes connection establishment now handles the
alias properly when determining if the peer port is on the same node
as the connected port.

An added benefit of addressing issue 1) is that some peer port
validation code has been relocated to TIPC's socket subsystem, which
means that validation is no longer done twice when a message is
sent to a non-socket port (such as TIPC's configuration service or
network topology service).

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-19 15:46:45 -04:00

98 lines
3.2 KiB
C

/*
* net/tipc/node_subscr.c: TIPC "node down" subscription handling
*
* Copyright (c) 1995-2006, Ericsson AB
* Copyright (c) 2005, 2010-2011, Wind River Systems
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "core.h"
#include "node_subscr.h"
#include "node.h"
/**
* tipc_nodesub_subscribe - create "node down" subscription for specified node
*/
void tipc_nodesub_subscribe(struct tipc_node_subscr *node_sub, u32 addr,
void *usr_handle, net_ev_handler handle_down)
{
if (in_own_node(addr)) {
node_sub->node = NULL;
return;
}
node_sub->node = tipc_node_find(addr);
if (!node_sub->node) {
warn("Node subscription rejected, unknown node 0x%x\n", addr);
return;
}
node_sub->handle_node_down = handle_down;
node_sub->usr_handle = usr_handle;
tipc_node_lock(node_sub->node);
list_add_tail(&node_sub->nodesub_list, &node_sub->node->nsub);
tipc_node_unlock(node_sub->node);
}
/**
* tipc_nodesub_unsubscribe - cancel "node down" subscription (if any)
*/
void tipc_nodesub_unsubscribe(struct tipc_node_subscr *node_sub)
{
if (!node_sub->node)
return;
tipc_node_lock(node_sub->node);
list_del_init(&node_sub->nodesub_list);
tipc_node_unlock(node_sub->node);
}
/**
* tipc_nodesub_notify - notify subscribers that a node is unreachable
*
* Note: node is locked by caller
*/
void tipc_nodesub_notify(struct tipc_node *node)
{
struct tipc_node_subscr *ns;
list_for_each_entry(ns, &node->nsub, nodesub_list) {
if (ns->handle_node_down) {
tipc_k_signal((Handler)ns->handle_node_down,
(unsigned long)ns->usr_handle);
ns->handle_node_down = NULL;
}
}
}