/* * 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); struct network tipc_net = { NULL }; 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 int net_init(void) { memset(&tipc_net, 0, sizeof(tipc_net)); tipc_net.zones = kcalloc(tipc_max_zones + 1, sizeof(struct _zone *), GFP_ATOMIC); if (!tipc_net.zones) { return -ENOMEM; } return 0; } 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(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(); if ((res = tipc_bearer_init()) || (res = net_init()) || (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", 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"); }