net.c revision c80262829769419e19527f972672e8df0480235a
1/* 2 * net/tipc/net.c: TIPC network routing code 3 * 4 * Copyright (c) 1995-2006, Ericsson AB 5 * Copyright (c) 2005, 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 "zone.h" 40#include "name_table.h" 41#include "name_distr.h" 42#include "subscr.h" 43#include "link.h" 44#include "port.h" 45#include "config.h" 46 47/* 48 * The TIPC locking policy is designed to ensure a very fine locking 49 * granularity, permitting complete parallel access to individual 50 * port and node/link instances. The code consists of three major 51 * locking domains, each protected with their own disjunct set of locks. 52 * 53 * 1: The routing hierarchy. 54 * Comprises the structures 'zone', 'cluster', 'node', 'link' 55 * and 'bearer'. The whole hierarchy is protected by a big 56 * read/write lock, tipc_net_lock, to enssure that nothing is added 57 * or removed while code is accessing any of these structures. 58 * This layer must not be called from the two others while they 59 * hold any of their own locks. 60 * Neither must it itself do any upcalls to the other two before 61 * it has released tipc_net_lock and other protective locks. 62 * 63 * Within the tipc_net_lock domain there are two sub-domains;'node' and 64 * 'bearer', where local write operations are permitted, 65 * provided that those are protected by individual spin_locks 66 * per instance. Code holding tipc_net_lock(read) and a node spin_lock 67 * is permitted to poke around in both the node itself and its 68 * subordinate links. I.e, it can update link counters and queues, 69 * change link state, send protocol messages, and alter the 70 * "active_links" array in the node; but it can _not_ remove a link 71 * or a node from the overall structure. 72 * Correspondingly, individual bearers may change status within a 73 * tipc_net_lock(read), protected by an individual spin_lock ber bearer 74 * instance, but it needs tipc_net_lock(write) to remove/add any bearers. 75 * 76 * 77 * 2: The transport level of the protocol. 78 * This consists of the structures port, (and its user level 79 * representations, such as user_port and tipc_sock), reference and 80 * tipc_user (port.c, reg.c, socket.c). 81 * 82 * This layer has four different locks: 83 * - The tipc_port spin_lock. This is protecting each port instance 84 * from parallel data access and removal. Since we can not place 85 * this lock in the port itself, it has been placed in the 86 * corresponding reference table entry, which has the same life 87 * cycle as the module. This entry is difficult to access from 88 * outside the TIPC core, however, so a pointer to the lock has 89 * been added in the port instance, -to be used for unlocking 90 * only. 91 * - A read/write lock to protect the reference table itself (teg.c). 92 * (Nobody is using read-only access to this, so it can just as 93 * well be changed to a spin_lock) 94 * - A spin lock to protect the registry of kernel/driver users (reg.c) 95 * - A global spin_lock (tipc_port_lock), which only task is to ensure 96 * consistency where more than one port is involved in an operation, 97 * i.e., whe a port is part of a linked list of ports. 98 * There are two such lists; 'port_list', which is used for management, 99 * and 'wait_list', which is used to queue ports during congestion. 100 * 101 * 3: The name table (name_table.c, name_distr.c, subscription.c) 102 * - There is one big read/write-lock (tipc_nametbl_lock) protecting the 103 * overall name table structure. Nothing must be added/removed to 104 * this structure without holding write access to it. 105 * - There is one local spin_lock per sub_sequence, which can be seen 106 * as a sub-domain to the tipc_nametbl_lock domain. It is used only 107 * for translation operations, and is needed because a translation 108 * steps the root of the 'publication' linked list between each lookup. 109 * This is always used within the scope of a tipc_nametbl_lock(read). 110 * - A local spin_lock protecting the queue of subscriber events. 111*/ 112 113DEFINE_RWLOCK(tipc_net_lock); 114static struct _zone *tipc_zones[256] = { NULL, }; 115struct network tipc_net = { tipc_zones }; 116 117struct tipc_node *tipc_net_select_remote_node(u32 addr, u32 ref) 118{ 119 return tipc_zone_select_remote_node(tipc_net.zones[tipc_zone(addr)], addr, ref); 120} 121 122u32 tipc_net_select_router(u32 addr, u32 ref) 123{ 124 return tipc_zone_select_router(tipc_net.zones[tipc_zone(addr)], addr, ref); 125} 126 127void tipc_net_remove_as_router(u32 router) 128{ 129 u32 z_num; 130 131 for (z_num = 1; z_num <= tipc_max_zones; z_num++) { 132 if (!tipc_net.zones[z_num]) 133 continue; 134 tipc_zone_remove_as_router(tipc_net.zones[z_num], router); 135 } 136} 137 138void tipc_net_send_external_routes(u32 dest) 139{ 140 u32 z_num; 141 142 for (z_num = 1; z_num <= tipc_max_zones; z_num++) { 143 if (tipc_net.zones[z_num]) 144 tipc_zone_send_external_routes(tipc_net.zones[z_num], dest); 145 } 146} 147 148static void net_stop(void) 149{ 150 u32 z_num; 151 152 for (z_num = 1; z_num <= tipc_max_zones; z_num++) 153 tipc_zone_delete(tipc_net.zones[z_num]); 154} 155 156static void net_route_named_msg(struct sk_buff *buf) 157{ 158 struct tipc_msg *msg = buf_msg(buf); 159 u32 dnode; 160 u32 dport; 161 162 if (!msg_named(msg)) { 163 msg_dbg(msg, "tipc_net->drop_nam:"); 164 buf_discard(buf); 165 return; 166 } 167 168 dnode = addr_domain(msg_lookup_scope(msg)); 169 dport = tipc_nametbl_translate(msg_nametype(msg), msg_nameinst(msg), &dnode); 170 dbg("tipc_net->lookup<%u,%u>-><%u,%x>\n", 171 msg_nametype(msg), msg_nameinst(msg), dport, dnode); 172 if (dport) { 173 msg_set_destnode(msg, dnode); 174 msg_set_destport(msg, dport); 175 tipc_net_route_msg(buf); 176 return; 177 } 178 msg_dbg(msg, "tipc_net->rej:NO NAME: "); 179 tipc_reject_msg(buf, TIPC_ERR_NO_NAME); 180} 181 182void tipc_net_route_msg(struct sk_buff *buf) 183{ 184 struct tipc_msg *msg; 185 u32 dnode; 186 187 if (!buf) 188 return; 189 msg = buf_msg(buf); 190 191 msg_incr_reroute_cnt(msg); 192 if (msg_reroute_cnt(msg) > 6) { 193 if (msg_errcode(msg)) { 194 msg_dbg(msg, "NET>DISC>:"); 195 buf_discard(buf); 196 } else { 197 msg_dbg(msg, "NET>REJ>:"); 198 tipc_reject_msg(buf, msg_destport(msg) ? 199 TIPC_ERR_NO_PORT : TIPC_ERR_NO_NAME); 200 } 201 return; 202 } 203 204 msg_dbg(msg, "tipc_net->rout: "); 205 206 /* Handle message for this node */ 207 dnode = msg_short(msg) ? tipc_own_addr : msg_destnode(msg); 208 if (tipc_in_scope(dnode, tipc_own_addr)) { 209 if (msg_isdata(msg)) { 210 if (msg_mcast(msg)) 211 tipc_port_recv_mcast(buf, NULL); 212 else if (msg_destport(msg)) 213 tipc_port_recv_msg(buf); 214 else 215 net_route_named_msg(buf); 216 return; 217 } 218 switch (msg_user(msg)) { 219 case ROUTE_DISTRIBUTOR: 220 tipc_cltr_recv_routing_table(buf); 221 break; 222 case NAME_DISTRIBUTOR: 223 tipc_named_recv(buf); 224 break; 225 case CONN_MANAGER: 226 tipc_port_recv_proto_msg(buf); 227 break; 228 default: 229 msg_dbg(msg,"DROP/NET/<REC<"); 230 buf_discard(buf); 231 } 232 return; 233 } 234 235 /* Handle message for another node */ 236 msg_dbg(msg, "NET>SEND>: "); 237 skb_trim(buf, msg_size(msg)); 238 tipc_link_send(buf, dnode, msg_link_selector(msg)); 239} 240 241int tipc_net_start(u32 addr) 242{ 243 char addr_string[16]; 244 int res; 245 246 if (tipc_mode != TIPC_NODE_MODE) 247 return -ENOPROTOOPT; 248 249 tipc_subscr_stop(); 250 tipc_cfg_stop(); 251 252 tipc_own_addr = addr; 253 tipc_mode = TIPC_NET_MODE; 254 tipc_named_reinit(); 255 tipc_port_reinit(); 256 257 if ((res = tipc_cltr_init()) || 258 (res = tipc_bclink_init())) { 259 return res; 260 } 261 262 tipc_k_signal((Handler)tipc_subscr_start, 0); 263 tipc_k_signal((Handler)tipc_cfg_init, 0); 264 265 info("Started in network mode\n"); 266 info("Own node address %s, network identity %u\n", 267 tipc_addr_string_fill(addr_string, tipc_own_addr), tipc_net_id); 268 return 0; 269} 270 271void tipc_net_stop(void) 272{ 273 if (tipc_mode != TIPC_NET_MODE) 274 return; 275 write_lock_bh(&tipc_net_lock); 276 tipc_bearer_stop(); 277 tipc_mode = TIPC_NODE_MODE; 278 tipc_bclink_stop(); 279 net_stop(); 280 write_unlock_bh(&tipc_net_lock); 281 info("Left network mode\n"); 282} 283 284