1/* 2 * net/tipc/net.c: TIPC network routing code 3 * 4 * Copyright (c) 1995-2006, Ericsson AB 5 * Copyright (c) 2005, 2010-2011, Wind River Systems 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the names of the copyright holders nor the names of its 17 * contributors may be used to endorse or promote products derived from 18 * this software without specific prior written permission. 19 * 20 * Alternatively, this software may be distributed under the terms of the 21 * GNU General Public License ("GPL") version 2 as published by the Free 22 * Software Foundation. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 34 * POSSIBILITY OF SUCH DAMAGE. 35 */ 36 37#include "core.h" 38#include "net.h" 39#include "name_distr.h" 40#include "subscr.h" 41#include "port.h" 42#include "node.h" 43#include "config.h" 44 45/* 46 * The TIPC locking policy is designed to ensure a very fine locking 47 * granularity, permitting complete parallel access to individual 48 * port and node/link instances. The code consists of three major 49 * locking domains, each protected with their own disjunct set of locks. 50 * 51 * 1: The routing hierarchy. 52 * Comprises the structures 'zone', 'cluster', 'node', 'link' 53 * and 'bearer'. The whole hierarchy is protected by a big 54 * read/write lock, tipc_net_lock, to enssure that nothing is added 55 * or removed while code is accessing any of these structures. 56 * This layer must not be called from the two others while they 57 * hold any of their own locks. 58 * Neither must it itself do any upcalls to the other two before 59 * it has released tipc_net_lock and other protective locks. 60 * 61 * Within the tipc_net_lock domain there are two sub-domains;'node' and 62 * 'bearer', where local write operations are permitted, 63 * provided that those are protected by individual spin_locks 64 * per instance. Code holding tipc_net_lock(read) and a node spin_lock 65 * is permitted to poke around in both the node itself and its 66 * subordinate links. I.e, it can update link counters and queues, 67 * change link state, send protocol messages, and alter the 68 * "active_links" array in the node; but it can _not_ remove a link 69 * or a node from the overall structure. 70 * Correspondingly, individual bearers may change status within a 71 * tipc_net_lock(read), protected by an individual spin_lock ber bearer 72 * instance, but it needs tipc_net_lock(write) to remove/add any bearers. 73 * 74 * 75 * 2: The transport level of the protocol. 76 * This consists of the structures port, (and its user level 77 * representations, such as user_port and tipc_sock), reference and 78 * tipc_user (port.c, reg.c, socket.c). 79 * 80 * This layer has four different locks: 81 * - The tipc_port spin_lock. This is protecting each port instance 82 * from parallel data access and removal. Since we can not place 83 * this lock in the port itself, it has been placed in the 84 * corresponding reference table entry, which has the same life 85 * cycle as the module. This entry is difficult to access from 86 * outside the TIPC core, however, so a pointer to the lock has 87 * been added in the port instance, -to be used for unlocking 88 * only. 89 * - A read/write lock to protect the reference table itself (teg.c). 90 * (Nobody is using read-only access to this, so it can just as 91 * well be changed to a spin_lock) 92 * - A spin lock to protect the registry of kernel/driver users (reg.c) 93 * - A global spin_lock (tipc_port_lock), which only task is to ensure 94 * consistency where more than one port is involved in an operation, 95 * i.e., whe a port is part of a linked list of ports. 96 * There are two such lists; 'port_list', which is used for management, 97 * and 'wait_list', which is used to queue ports during congestion. 98 * 99 * 3: The name table (name_table.c, name_distr.c, subscription.c) 100 * - There is one big read/write-lock (tipc_nametbl_lock) protecting the 101 * overall name table structure. Nothing must be added/removed to 102 * this structure without holding write access to it. 103 * - There is one local spin_lock per sub_sequence, which can be seen 104 * as a sub-domain to the tipc_nametbl_lock domain. It is used only 105 * for translation operations, and is needed because a translation 106 * steps the root of the 'publication' linked list between each lookup. 107 * This is always used within the scope of a tipc_nametbl_lock(read). 108 * - A local spin_lock protecting the queue of subscriber events. 109*/ 110 111DEFINE_RWLOCK(tipc_net_lock); 112 113static void net_route_named_msg(struct sk_buff *buf) 114{ 115 struct tipc_msg *msg = buf_msg(buf); 116 u32 dnode; 117 u32 dport; 118 119 if (!msg_named(msg)) { 120 kfree_skb(buf); 121 return; 122 } 123 124 dnode = addr_domain(msg_lookup_scope(msg)); 125 dport = tipc_nametbl_translate(msg_nametype(msg), msg_nameinst(msg), &dnode); 126 if (dport) { 127 msg_set_destnode(msg, dnode); 128 msg_set_destport(msg, dport); 129 tipc_net_route_msg(buf); 130 return; 131 } 132 tipc_reject_msg(buf, TIPC_ERR_NO_NAME); 133} 134 135void tipc_net_route_msg(struct sk_buff *buf) 136{ 137 struct tipc_msg *msg; 138 u32 dnode; 139 140 if (!buf) 141 return; 142 msg = buf_msg(buf); 143 144 /* Handle message for this node */ 145 dnode = msg_short(msg) ? tipc_own_addr : msg_destnode(msg); 146 if (tipc_in_scope(dnode, tipc_own_addr)) { 147 if (msg_isdata(msg)) { 148 if (msg_mcast(msg)) 149 tipc_port_recv_mcast(buf, NULL); 150 else if (msg_destport(msg)) 151 tipc_port_recv_msg(buf); 152 else 153 net_route_named_msg(buf); 154 return; 155 } 156 switch (msg_user(msg)) { 157 case NAME_DISTRIBUTOR: 158 tipc_named_recv(buf); 159 break; 160 case CONN_MANAGER: 161 tipc_port_recv_proto_msg(buf); 162 break; 163 default: 164 kfree_skb(buf); 165 } 166 return; 167 } 168 169 /* Handle message for another node */ 170 skb_trim(buf, msg_size(msg)); 171 tipc_link_send(buf, dnode, msg_link_selector(msg)); 172} 173 174void tipc_net_start(u32 addr) 175{ 176 char addr_string[16]; 177 178 write_lock_bh(&tipc_net_lock); 179 tipc_own_addr = addr; 180 tipc_named_reinit(); 181 tipc_port_reinit(); 182 tipc_bclink_init(); 183 write_unlock_bh(&tipc_net_lock); 184 185 tipc_cfg_reinit(); 186 187 pr_info("Started in network mode\n"); 188 pr_info("Own node address %s, network identity %u\n", 189 tipc_addr_string_fill(addr_string, tipc_own_addr), tipc_net_id); 190} 191 192void tipc_net_stop(void) 193{ 194 struct tipc_node *node, *t_node; 195 196 if (!tipc_own_addr) 197 return; 198 write_lock_bh(&tipc_net_lock); 199 tipc_bearer_stop(); 200 tipc_bclink_stop(); 201 list_for_each_entry_safe(node, t_node, &tipc_node_list, list) 202 tipc_node_delete(node); 203 write_unlock_bh(&tipc_net_lock); 204 pr_info("Left network mode\n"); 205} 206