linux/net/tipc/addr.c
Jon Paul Maloy d482994fca tipc: fix two bugs in secondary destination lookup
A message sent to a node after a successful name table lookup may still
find that the destination socket has disappeared, because distribution
of name table updates is non-atomic. If so, the message will be rejected
back to the sender with error code TIPC_ERR_NO_PORT. If the source
socket of the message has disappeared in the meantime, the message
should be dropped.

However, in the currrent code, the message will instead be subject to an
unwanted tertiary lookup, because the function tipc_msg_lookup_dest()
doesn't check if there is an error code present in the message before
performing the lookup. In the worst case, the message may now find the
old destination again, and be redirected once more, instead of being
dropped directly as it should be.

A second bug in this function is that the "prev_node" field in the message
is not updated after successful lookup, something that may have
unpredictable consequences.

The problems arising from those bugs occur very infrequently.

The third change in this function; the test on msg_reroute_msg_cnt() is
purely cosmetic, reflecting that the returned value never can be negative.

This commit corrects the two bugs described above.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-29 13:47:36 -07:00

154 lines
4.4 KiB
C

/*
* net/tipc/addr.c: TIPC address utility routines
*
* Copyright (c) 2000-2006, 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.
*/
#include <linux/kernel.h>
#include "addr.h"
#include "core.h"
u32 tipc_own_addr(struct net *net)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
return tn->own_addr;
}
/**
* in_own_cluster - test for cluster inclusion; <0.0.0> always matches
*/
int in_own_cluster(struct net *net, u32 addr)
{
return in_own_cluster_exact(net, addr) || !addr;
}
int in_own_cluster_exact(struct net *net, u32 addr)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
return !((addr ^ tn->own_addr) >> 12);
}
/**
* in_own_node - test for node inclusion; <0.0.0> always matches
*/
int in_own_node(struct net *net, u32 addr)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
return (addr == tn->own_addr) || !addr;
}
/**
* addr_domain - convert 2-bit scope value to equivalent message lookup domain
*
* Needed when address of a named message must be looked up a second time
* after a network hop.
*/
u32 addr_domain(struct net *net, u32 sc)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
if (likely(sc == TIPC_NODE_SCOPE))
return tn->own_addr;
if (sc == TIPC_CLUSTER_SCOPE)
return tipc_cluster_mask(tn->own_addr);
return tipc_zone_mask(tn->own_addr);
}
/**
* tipc_addr_domain_valid - validates a network domain address
*
* Accepts <Z.C.N>, <Z.C.0>, <Z.0.0>, and <0.0.0>,
* where Z, C, and N are non-zero.
*
* Returns 1 if domain address is valid, otherwise 0
*/
int tipc_addr_domain_valid(u32 addr)
{
u32 n = tipc_node(addr);
u32 c = tipc_cluster(addr);
u32 z = tipc_zone(addr);
if (n && (!z || !c))
return 0;
if (c && !z)
return 0;
return 1;
}
/**
* tipc_addr_node_valid - validates a proposed network address for this node
*
* Accepts <Z.C.N>, where Z, C, and N are non-zero.
*
* Returns 1 if address can be used, otherwise 0
*/
int tipc_addr_node_valid(u32 addr)
{
return tipc_addr_domain_valid(addr) && tipc_node(addr);
}
int tipc_in_scope(u32 domain, u32 addr)
{
if (!domain || (domain == addr))
return 1;
if (domain == tipc_cluster_mask(addr)) /* domain <Z.C.0> */
return 1;
if (domain == tipc_zone_mask(addr)) /* domain <Z.0.0> */
return 1;
return 0;
}
/**
* tipc_addr_scope - convert message lookup domain to a 2-bit scope value
*/
int tipc_addr_scope(u32 domain)
{
if (likely(!domain))
return TIPC_ZONE_SCOPE;
if (tipc_node(domain))
return TIPC_NODE_SCOPE;
if (tipc_cluster(domain))
return TIPC_CLUSTER_SCOPE;
return TIPC_ZONE_SCOPE;
}
char *tipc_addr_string_fill(char *string, u32 addr)
{
snprintf(string, 16, "<%u.%u.%u>",
tipc_zone(addr), tipc_cluster(addr), tipc_node(addr));
return string;
}