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+/*
+ * net/tipc/net.c: TIPC network routing code
+ *
+ * Copyright (c) 2003-2005, Ericsson Research Canada
+ * Copyright (c) 2005, Wind River Systems
+ * Copyright (c) 2005-2006, Ericsson AB
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ * 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.
+ * 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.
+ *
+ * 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, 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 net_lock and other protective locks.
+ *
+ * Within the 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 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
+ * net_lock(read), protected by an individual spin_lock ber bearer
+ * instance, but it needs 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 (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 (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 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 nametbl_lock(read).
+ * - A local spin_lock protecting the queue of subscriber events.
+*/
+
+rwlock_t net_lock = RW_LOCK_UNLOCKED;
+struct network net = { 0 };
+
+struct node *net_select_remote_node(u32 addr, u32 ref)
+{
+ return zone_select_remote_node(net.zones[tipc_zone(addr)], addr, ref);
+}
+
+u32 net_select_router(u32 addr, u32 ref)
+{
+ return zone_select_router(net.zones[tipc_zone(addr)], addr, ref);
+}
+
+
+u32 net_next_node(u32 a)
+{
+ if (net.zones[tipc_zone(a)])
+ return zone_next_node(a);
+ return 0;
+}
+
+void net_remove_as_router(u32 router)
+{
+ u32 z_num;
+
+ for (z_num = 1; z_num <= tipc_max_zones; z_num++) {
+ if (!net.zones[z_num])
+ continue;
+ zone_remove_as_router(net.zones[z_num], router);
+ }
+}
+
+void net_send_external_routes(u32 dest)
+{
+ u32 z_num;
+
+ for (z_num = 1; z_num <= tipc_max_zones; z_num++) {
+ if (net.zones[z_num])
+ zone_send_external_routes(net.zones[z_num], dest);
+ }
+}
+
+int net_init(void)
+{
+ u32 sz = sizeof(struct _zone *) * (tipc_max_zones + 1);
+
+ memset(&net, 0, sizeof(net));
+ net.zones = (struct _zone **)kmalloc(sz, GFP_ATOMIC);
+ if (!net.zones) {
+ return -ENOMEM;
+ }
+ memset(net.zones, 0, sz);
+ return TIPC_OK;
+}
+
+void net_stop(void)
+{
+ u32 z_num;
+
+ if (!net.zones)
+ return;
+
+ for (z_num = 1; z_num <= tipc_max_zones; z_num++) {
+ zone_delete(net.zones[z_num]);
+ }
+ kfree(net.zones);
+ net.zones = 0;
+}
+
+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, "net->drop_nam:");
+ buf_discard(buf);
+ return;
+ }
+
+ dnode = addr_domain(msg_lookup_scope(msg));
+ dport = nametbl_translate(msg_nametype(msg), msg_nameinst(msg), &dnode);
+ dbg("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);
+ net_route_msg(buf);
+ return;
+ }
+ msg_dbg(msg, "net->rej:NO NAME: ");
+ tipc_reject_msg(buf, TIPC_ERR_NO_NAME);
+}
+
+void 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, "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))
+ port_recv_mcast(buf, NULL);
+ else if (msg_destport(msg))
+ port_recv_msg(buf);
+ else
+ net_route_named_msg(buf);
+ return;
+ }
+ switch (msg_user(msg)) {
+ case ROUTE_DISTRIBUTOR:
+ cluster_recv_routing_table(buf);
+ break;
+ case NAME_DISTRIBUTOR:
+ named_recv(buf);
+ break;
+ case CONN_MANAGER:
+ 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>: ");
+ link_send(buf, dnode, msg_link_selector(msg));
+}
+
+int tipc_start_net(void)
+{
+ char addr_string[16];
+ int res;
+
+ if (tipc_mode != TIPC_NODE_MODE)
+ return -ENOPROTOOPT;
+
+ tipc_mode = TIPC_NET_MODE;
+ named_reinit();
+ port_reinit();
+
+ if ((res = bearer_init()) ||
+ (res = net_init()) ||
+ (res = cluster_init()) ||
+ (res = bclink_init())) {
+ return res;
+ }
+ subscr_stop();
+ cfg_stop();
+ k_signal((Handler)subscr_start, 0);
+ k_signal((Handler)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_stop_net(void)
+{
+ if (tipc_mode != TIPC_NET_MODE)
+ return;
+ write_lock_bh(&net_lock);
+ bearer_stop();
+ tipc_mode = TIPC_NODE_MODE;
+ bclink_stop();
+ net_stop();
+ write_unlock_bh(&net_lock);
+ info("Left network mode \n");
+}
+
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