/*
* 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.
*/
rwlock_t tipc_net_lock = RW_LOCK_UNLOCKED;
struct network tipc_net = { NULL };
struct 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);
}
u32 tipc_net_next_node(u32 a)
{
if (tipc_net.zones[tipc_zone(a)])
return tipc_zone_next_node(a);
return 0;
}
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 int net_init(void)
{
u32 sz = sizeof(struct _zone *) * (tipc_max_zones + 1);
memset(&tipc_net, 0, sizeof(tipc_net));
tipc_net.zones = (struct _zone **)kmalloc(sz, GFP_ATOMIC);
if (!tipc_net.zones) {
return -ENOMEM;
}
memset(tipc_net.zones, 0, sz);
return TIPC_OK;
}
static void net_stop(void)
{
u32 z_num;
if (!tipc_net.zones)
return;
for (z_num = 1; z_num <= tipc_max_zones; z_num++) {
tipc_zone_delete(tipc_net.zones[z_num]);
}
kfree(tipc_net.zones);
tipc_net.zones = NULL;
}
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 (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(void)
{
char addr_string[16];
int res;
if (tipc_mode != TIPC_NODE_MODE)
return -ENOPROTOOPT;
tipc_mode = TIPC_NET_MODE;
tipc_named_reinit();
tipc_port_reinit();
if ((res = tipc_bearer_init()) ||
(res = net_init()) ||
(res = tipc_cltr_init()) ||
(res = tipc_bclink_init())) {
return res;
}
tipc_subscr_stop();
tipc_cfg_stop();
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",
addr_string_fill(addr_string, tipc_own_addr), tipc_net_id);
return TIPC_OK;
}
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");
}
