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linux/net/tipc/net.c

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/*
* net/tipc/net.c: TIPC network routing code
*
* Copyright (c) 1995-2006, Ericsson AB
* Copyright (c) 2005, 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 "bearer.h"
#include "net.h"
#include "zone.h"
#include "addr.h"
#include "name_table.h"
#include "name_distr.h"
#include "subscr.h"
#include "link.h"
#include "msg.h"
#include "port.h"
#include "bcast.h"
#include "discover.h"
#include "config.h"
/*
* The TIPC locking policy is designed to ensure a very fine locking
* granularity, permitting complete parallel access to individual
* port and node/link instances. The code consists of three major
* locking domains, each protected with their own disjunct set of locks.
*
* 1: The routing hierarchy.
* Comprises the structures 'zone', 'cluster', 'node', 'link'
* and 'bearer'. The whole hierarchy is protected by a big
* read/write lock, tipc_net_lock, to enssure that nothing is added
* or removed while code is accessing any of these structures.
* This layer must not be called from the two others while they
* hold any of their own locks.
* Neither must it itself do any upcalls to the other two before
* it has released tipc_net_lock and other protective locks.
*
* Within the tipc_net_lock domain there are two sub-domains;'node' and
* 'bearer', where local write operations are permitted,
* provided that those are protected by individual spin_locks
* per instance. Code holding tipc_net_lock(read) and a node spin_lock
* is permitted to poke around in both the node itself and its
* subordinate links. I.e, it can update link counters and queues,
* change link state, send protocol messages, and alter the
* "active_links" array in the node; but it can _not_ remove a link
* or a node from the overall structure.
* Correspondingly, individual bearers may change status within a
* tipc_net_lock(read), protected by an individual spin_lock ber bearer
* instance, but it needs tipc_net_lock(write) to remove/add any bearers.
*
*
* 2: The transport level of the protocol.
* This consists of the structures port, (and its user level
* representations, such as user_port and tipc_sock), reference and
* tipc_user (port.c, reg.c, socket.c).
*
* This layer has four different locks:
* - The tipc_port spin_lock. This is protecting each port instance
* from parallel data access and removal. Since we can not place
* this lock in the port itself, it has been placed in the
* corresponding reference table entry, which has the same life
* cycle as the module. This entry is difficult to access from
* outside the TIPC core, however, so a pointer to the lock has
* been added in the port instance, -to be used for unlocking
* only.
* - A read/write lock to protect the reference table itself (teg.c).
* (Nobody is using read-only access to this, so it can just as
* well be changed to a spin_lock)
* - A spin lock to protect the registry of kernel/driver users (reg.c)
* - A global spin_lock (tipc_port_lock), which only task is to ensure
* consistency where more than one port is involved in an operation,
* i.e., whe a port is part of a linked list of ports.
* There are two such lists; 'port_list', which is used for management,
* and 'wait_list', which is used to queue ports during congestion.
*
* 3: The name table (name_table.c, name_distr.c, subscription.c)
* - There is one big read/write-lock (tipc_nametbl_lock) protecting the
* overall name table structure. Nothing must be added/removed to
* this structure without holding write access to it.
* - There is one local spin_lock per sub_sequence, which can be seen
* as a sub-domain to the tipc_nametbl_lock domain. It is used only
* for translation operations, and is needed because a translation
* steps the root of the 'publication' linked list between each lookup.
* This is always used within the scope of a tipc_nametbl_lock(read).
* - A local spin_lock protecting the queue of subscriber events.
*/
DEFINE_RWLOCK(tipc_net_lock);
static struct _zone *tipc_zones[256] = { NULL, };
tipc: Fix oops on send prior to entering networked mode (v3) Fix TIPC to disallow sending to remote addresses prior to entering NET_MODE user programs can oops the kernel by sending datagrams via AF_TIPC prior to entering networked mode. The following backtrace has been observed: ID: 13459 TASK: ffff810014640040 CPU: 0 COMMAND: "tipc-client" [exception RIP: tipc_node_select_next_hop+90] RIP: ffffffff8869d3c3 RSP: ffff81002d9a5ab8 RFLAGS: 00010202 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000001001001 RBP: 0000000001001001 R8: 0074736575716552 R9: 0000000000000000 R10: ffff81003fbd0680 R11: 00000000000000c8 R12: 0000000000000008 R13: 0000000000000001 R14: 0000000000000001 R15: ffff810015c6ca00 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 RIP: 0000003cbd8d49a3 RSP: 00007fffc84e0be8 RFLAGS: 00010206 RAX: 000000000000002c RBX: ffffffff8005d116 RCX: 0000000000000000 RDX: 0000000000000008 RSI: 00007fffc84e0c00 RDI: 0000000000000003 RBP: 0000000000000000 R8: 00007fffc84e0c10 R9: 0000000000000010 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffc84e0d10 R14: 0000000000000000 R15: 00007fffc84e0c30 ORIG_RAX: 000000000000002c CS: 0033 SS: 002b What happens is that, when the tipc module in inserted it enters a standalone node mode in which communication to its own address is allowed <0.0.0> but not to other addresses, since the appropriate data structures have not been allocated yet (specifically the tipc_net pointer). There is nothing stopping a client from trying to send such a message however, and if that happens, we attempt to dereference tipc_net.zones while the pointer is still NULL, and explode. The fix is pretty straightforward. Since these oopses all arise from the dereference of global pointers prior to their assignment to allocated values, and since these allocations are small (about 2k total), lets convert these pointers to static arrays of the appropriate size. All the accesses to these bits consider 0/NULL to be a non match when searching, so all the lookups still work properly, and there is no longer a chance of a bad dererence anywhere. As a bonus, this lets us eliminate the setup/teardown routines for those pointers, and elimnates the need to preform any locking around them to prevent access while their being allocated/freed. I've updated the tipc_net structure to behave this way to fix the exact reported problem, and also fixed up the tipc_bearers and media_list arrays to fix an obvious simmilar problem that arises from issuing tipc-config commands to manipulate bearers/links prior to entering networked mode I've tested this for a few hours by running the sanity tests and stress test with the tipcutils suite, and nothing has fallen over. There have been a few lockdep warnings, but those were there before, and can be addressed later, as they didn't actually result in any deadlock. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> CC: Allan Stephens <allan.stephens@windriver.com> CC: David S. Miller <davem@davemloft.net> CC: tipc-discussion@lists.sourceforge.net bearer.c | 37 ++++++------------------------------- bearer.h | 2 +- net.c | 25 ++++--------------------- 3 files changed, 11 insertions(+), 53 deletions(-) Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-03 01:31:23 -07:00
struct network tipc_net = { tipc_zones };
struct tipc_node *tipc_net_select_remote_node(u32 addr, u32 ref)
{
return tipc_zone_select_remote_node(tipc_net.zones[tipc_zone(addr)], addr, ref);
}
u32 tipc_net_select_router(u32 addr, u32 ref)
{
return tipc_zone_select_router(tipc_net.zones[tipc_zone(addr)], addr, ref);
}
#if 0
u32 tipc_net_next_node(u32 a)
{
if (tipc_net.zones[tipc_zone(a)])
return tipc_zone_next_node(a);
return 0;
}
#endif
void tipc_net_remove_as_router(u32 router)
{
u32 z_num;
for (z_num = 1; z_num <= tipc_max_zones; z_num++) {
if (!tipc_net.zones[z_num])
continue;
tipc_zone_remove_as_router(tipc_net.zones[z_num], router);
}
}
void tipc_net_send_external_routes(u32 dest)
{
u32 z_num;
for (z_num = 1; z_num <= tipc_max_zones; z_num++) {
if (tipc_net.zones[z_num])
tipc_zone_send_external_routes(tipc_net.zones[z_num], dest);
}
}
static void net_stop(void)
{
u32 z_num;
tipc: Fix oops on send prior to entering networked mode (v3) Fix TIPC to disallow sending to remote addresses prior to entering NET_MODE user programs can oops the kernel by sending datagrams via AF_TIPC prior to entering networked mode. The following backtrace has been observed: ID: 13459 TASK: ffff810014640040 CPU: 0 COMMAND: "tipc-client" [exception RIP: tipc_node_select_next_hop+90] RIP: ffffffff8869d3c3 RSP: ffff81002d9a5ab8 RFLAGS: 00010202 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000001001001 RBP: 0000000001001001 R8: 0074736575716552 R9: 0000000000000000 R10: ffff81003fbd0680 R11: 00000000000000c8 R12: 0000000000000008 R13: 0000000000000001 R14: 0000000000000001 R15: ffff810015c6ca00 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 RIP: 0000003cbd8d49a3 RSP: 00007fffc84e0be8 RFLAGS: 00010206 RAX: 000000000000002c RBX: ffffffff8005d116 RCX: 0000000000000000 RDX: 0000000000000008 RSI: 00007fffc84e0c00 RDI: 0000000000000003 RBP: 0000000000000000 R8: 00007fffc84e0c10 R9: 0000000000000010 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffc84e0d10 R14: 0000000000000000 R15: 00007fffc84e0c30 ORIG_RAX: 000000000000002c CS: 0033 SS: 002b What happens is that, when the tipc module in inserted it enters a standalone node mode in which communication to its own address is allowed <0.0.0> but not to other addresses, since the appropriate data structures have not been allocated yet (specifically the tipc_net pointer). There is nothing stopping a client from trying to send such a message however, and if that happens, we attempt to dereference tipc_net.zones while the pointer is still NULL, and explode. The fix is pretty straightforward. Since these oopses all arise from the dereference of global pointers prior to their assignment to allocated values, and since these allocations are small (about 2k total), lets convert these pointers to static arrays of the appropriate size. All the accesses to these bits consider 0/NULL to be a non match when searching, so all the lookups still work properly, and there is no longer a chance of a bad dererence anywhere. As a bonus, this lets us eliminate the setup/teardown routines for those pointers, and elimnates the need to preform any locking around them to prevent access while their being allocated/freed. I've updated the tipc_net structure to behave this way to fix the exact reported problem, and also fixed up the tipc_bearers and media_list arrays to fix an obvious simmilar problem that arises from issuing tipc-config commands to manipulate bearers/links prior to entering networked mode I've tested this for a few hours by running the sanity tests and stress test with the tipcutils suite, and nothing has fallen over. There have been a few lockdep warnings, but those were there before, and can be addressed later, as they didn't actually result in any deadlock. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> CC: Allan Stephens <allan.stephens@windriver.com> CC: David S. Miller <davem@davemloft.net> CC: tipc-discussion@lists.sourceforge.net bearer.c | 37 ++++++------------------------------- bearer.h | 2 +- net.c | 25 ++++--------------------- 3 files changed, 11 insertions(+), 53 deletions(-) Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-03 01:31:23 -07:00
for (z_num = 1; z_num <= tipc_max_zones; z_num++)
tipc_zone_delete(tipc_net.zones[z_num]);
}
static void net_route_named_msg(struct sk_buff *buf)
{
struct tipc_msg *msg = buf_msg(buf);
u32 dnode;
u32 dport;
if (!msg_named(msg)) {
msg_dbg(msg, "tipc_net->drop_nam:");
buf_discard(buf);
return;
}
dnode = addr_domain(msg_lookup_scope(msg));
dport = tipc_nametbl_translate(msg_nametype(msg), msg_nameinst(msg), &dnode);
dbg("tipc_net->lookup<%u,%u>-><%u,%x>\n",
msg_nametype(msg), msg_nameinst(msg), dport, dnode);
if (dport) {
msg_set_destnode(msg, dnode);
msg_set_destport(msg, dport);
tipc_net_route_msg(buf);
return;
}
msg_dbg(msg, "tipc_net->rej:NO NAME: ");
tipc_reject_msg(buf, TIPC_ERR_NO_NAME);
}
void tipc_net_route_msg(struct sk_buff *buf)
{
struct tipc_msg *msg;
u32 dnode;
if (!buf)
return;
msg = buf_msg(buf);
msg_incr_reroute_cnt(msg);
if (msg_reroute_cnt(msg) > 6) {
if (msg_errcode(msg)) {
msg_dbg(msg, "NET>DISC>:");
buf_discard(buf);
} else {
msg_dbg(msg, "NET>REJ>:");
tipc_reject_msg(buf, msg_destport(msg) ?
TIPC_ERR_NO_PORT : TIPC_ERR_NO_NAME);
}
return;
}
msg_dbg(msg, "tipc_net->rout: ");
/* Handle message for this node */
dnode = msg_short(msg) ? tipc_own_addr : msg_destnode(msg);
if (tipc_in_scope(dnode, tipc_own_addr)) {
if (msg_isdata(msg)) {
if (msg_mcast(msg))
tipc_port_recv_mcast(buf, NULL);
else if (msg_destport(msg))
tipc_port_recv_msg(buf);
else
net_route_named_msg(buf);
return;
}
switch (msg_user(msg)) {
case ROUTE_DISTRIBUTOR:
tipc_cltr_recv_routing_table(buf);
break;
case NAME_DISTRIBUTOR:
tipc_named_recv(buf);
break;
case CONN_MANAGER:
tipc_port_recv_proto_msg(buf);
break;
default:
msg_dbg(msg,"DROP/NET/<REC<");
buf_discard(buf);
}
return;
}
/* Handle message for another node */
msg_dbg(msg, "NET>SEND>: ");
tipc_link_send(buf, dnode, msg_link_selector(msg));
}
int tipc_net_start(u32 addr)
{
char addr_string[16];
int res;
if (tipc_mode != TIPC_NODE_MODE)
return -ENOPROTOOPT;
tipc_subscr_stop();
tipc_cfg_stop();
tipc_own_addr = addr;
tipc_mode = TIPC_NET_MODE;
tipc_named_reinit();
tipc_port_reinit();
tipc: Fix oops on send prior to entering networked mode (v3) Fix TIPC to disallow sending to remote addresses prior to entering NET_MODE user programs can oops the kernel by sending datagrams via AF_TIPC prior to entering networked mode. The following backtrace has been observed: ID: 13459 TASK: ffff810014640040 CPU: 0 COMMAND: "tipc-client" [exception RIP: tipc_node_select_next_hop+90] RIP: ffffffff8869d3c3 RSP: ffff81002d9a5ab8 RFLAGS: 00010202 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000001001001 RBP: 0000000001001001 R8: 0074736575716552 R9: 0000000000000000 R10: ffff81003fbd0680 R11: 00000000000000c8 R12: 0000000000000008 R13: 0000000000000001 R14: 0000000000000001 R15: ffff810015c6ca00 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 RIP: 0000003cbd8d49a3 RSP: 00007fffc84e0be8 RFLAGS: 00010206 RAX: 000000000000002c RBX: ffffffff8005d116 RCX: 0000000000000000 RDX: 0000000000000008 RSI: 00007fffc84e0c00 RDI: 0000000000000003 RBP: 0000000000000000 R8: 00007fffc84e0c10 R9: 0000000000000010 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffc84e0d10 R14: 0000000000000000 R15: 00007fffc84e0c30 ORIG_RAX: 000000000000002c CS: 0033 SS: 002b What happens is that, when the tipc module in inserted it enters a standalone node mode in which communication to its own address is allowed <0.0.0> but not to other addresses, since the appropriate data structures have not been allocated yet (specifically the tipc_net pointer). There is nothing stopping a client from trying to send such a message however, and if that happens, we attempt to dereference tipc_net.zones while the pointer is still NULL, and explode. The fix is pretty straightforward. Since these oopses all arise from the dereference of global pointers prior to their assignment to allocated values, and since these allocations are small (about 2k total), lets convert these pointers to static arrays of the appropriate size. All the accesses to these bits consider 0/NULL to be a non match when searching, so all the lookups still work properly, and there is no longer a chance of a bad dererence anywhere. As a bonus, this lets us eliminate the setup/teardown routines for those pointers, and elimnates the need to preform any locking around them to prevent access while their being allocated/freed. I've updated the tipc_net structure to behave this way to fix the exact reported problem, and also fixed up the tipc_bearers and media_list arrays to fix an obvious simmilar problem that arises from issuing tipc-config commands to manipulate bearers/links prior to entering networked mode I've tested this for a few hours by running the sanity tests and stress test with the tipcutils suite, and nothing has fallen over. There have been a few lockdep warnings, but those were there before, and can be addressed later, as they didn't actually result in any deadlock. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> CC: Allan Stephens <allan.stephens@windriver.com> CC: David S. Miller <davem@davemloft.net> CC: tipc-discussion@lists.sourceforge.net bearer.c | 37 ++++++------------------------------- bearer.h | 2 +- net.c | 25 ++++--------------------- 3 files changed, 11 insertions(+), 53 deletions(-) Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-03 01:31:23 -07:00
if ((res = tipc_cltr_init()) ||
(res = tipc_bclink_init())) {
return res;
}
tipc_k_signal((Handler)tipc_subscr_start, 0);
tipc_k_signal((Handler)tipc_cfg_init, 0);
info("Started in network mode\n");
info("Own node address %s, network identity %u\n",
tipc_addr_string_fill(addr_string, tipc_own_addr), tipc_net_id);
return 0;
}
void tipc_net_stop(void)
{
if (tipc_mode != TIPC_NET_MODE)
return;
write_lock_bh(&tipc_net_lock);
tipc_bearer_stop();
tipc_mode = TIPC_NODE_MODE;
tipc_bclink_stop();
net_stop();
write_unlock_bh(&tipc_net_lock);
info("Left network mode\n");
}