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 "bearer.h" 39 #include "net.h" 40 #include "zone.h" 41 #include "addr.h" 42 #include "name_table.h" 43 #include "name_distr.h" 44 #include "subscr.h" 45 #include "link.h" 46 #include "msg.h" 47 #include "port.h" 48 #include "bcast.h" 49 #include "discover.h" 50 #include "config.h" 51 52 /* 53 * The TIPC locking policy is designed to ensure a very fine locking 54 * granularity, permitting complete parallel access to individual 55 * port and node/link instances. The code consists of three major 56 * locking domains, each protected with their own disjunct set of locks. 57 * 58 * 1: The routing hierarchy. 59 * Comprises the structures 'zone', 'cluster', 'node', 'link' 60 * and 'bearer'. The whole hierarchy is protected by a big 61 * read/write lock, tipc_net_lock, to enssure that nothing is added 62 * or removed while code is accessing any of these structures. 63 * This layer must not be called from the two others while they 64 * hold any of their own locks. 65 * Neither must it itself do any upcalls to the other two before 66 * it has released tipc_net_lock and other protective locks. 67 * 68 * Within the tipc_net_lock domain there are two sub-domains;'node' and 69 * 'bearer', where local write operations are permitted, 70 * provided that those are protected by individual spin_locks 71 * per instance. Code holding tipc_net_lock(read) and a node spin_lock 72 * is permitted to poke around in both the node itself and its 73 * subordinate links. I.e, it can update link counters and queues, 74 * change link state, send protocol messages, and alter the 75 * "active_links" array in the node; but it can _not_ remove a link 76 * or a node from the overall structure. 77 * Correspondingly, individual bearers may change status within a 78 * tipc_net_lock(read), protected by an individual spin_lock ber bearer 79 * instance, but it needs tipc_net_lock(write) to remove/add any bearers. 80 * 81 * 82 * 2: The transport level of the protocol. 83 * This consists of the structures port, (and its user level 84 * representations, such as user_port and tipc_sock), reference and 85 * tipc_user (port.c, reg.c, socket.c). 86 * 87 * This layer has four different locks: 88 * - The tipc_port spin_lock. This is protecting each port instance 89 * from parallel data access and removal. Since we can not place 90 * this lock in the port itself, it has been placed in the 91 * corresponding reference table entry, which has the same life 92 * cycle as the module. This entry is difficult to access from 93 * outside the TIPC core, however, so a pointer to the lock has 94 * been added in the port instance, -to be used for unlocking 95 * only. 96 * - A read/write lock to protect the reference table itself (teg.c). 97 * (Nobody is using read-only access to this, so it can just as 98 * well be changed to a spin_lock) 99 * - A spin lock to protect the registry of kernel/driver users (reg.c) 100 * - A global spin_lock (tipc_port_lock), which only task is to ensure 101 * consistency where more than one port is involved in an operation, 102 * i.e., whe a port is part of a linked list of ports. 103 * There are two such lists; 'port_list', which is used for management, 104 * and 'wait_list', which is used to queue ports during congestion. 105 * 106 * 3: The name table (name_table.c, name_distr.c, subscription.c) 107 * - There is one big read/write-lock (tipc_nametbl_lock) protecting the 108 * overall name table structure. Nothing must be added/removed to 109 * this structure without holding write access to it. 110 * - There is one local spin_lock per sub_sequence, which can be seen 111 * as a sub-domain to the tipc_nametbl_lock domain. It is used only 112 * for translation operations, and is needed because a translation 113 * steps the root of the 'publication' linked list between each lookup. 114 * This is always used within the scope of a tipc_nametbl_lock(read). 115 * - A local spin_lock protecting the queue of subscriber events. 116 */ 117 118 DEFINE_RWLOCK(tipc_net_lock); 119 static struct _zone *tipc_zones[256] = { NULL, }; 120 struct network tipc_net = { tipc_zones }; 121 122 struct tipc_node *tipc_net_select_remote_node(u32 addr, u32 ref) 123 { 124 return tipc_zone_select_remote_node(tipc_net.zones[tipc_zone(addr)], addr, ref); 125 } 126 127 u32 tipc_net_select_router(u32 addr, u32 ref) 128 { 129 return tipc_zone_select_router(tipc_net.zones[tipc_zone(addr)], addr, ref); 130 } 131 132 #if 0 133 u32 tipc_net_next_node(u32 a) 134 { 135 if (tipc_net.zones[tipc_zone(a)]) 136 return tipc_zone_next_node(a); 137 return 0; 138 } 139 #endif 140 141 void tipc_net_remove_as_router(u32 router) 142 { 143 u32 z_num; 144 145 for (z_num = 1; z_num <= tipc_max_zones; z_num++) { 146 if (!tipc_net.zones[z_num]) 147 continue; 148 tipc_zone_remove_as_router(tipc_net.zones[z_num], router); 149 } 150 } 151 152 void tipc_net_send_external_routes(u32 dest) 153 { 154 u32 z_num; 155 156 for (z_num = 1; z_num <= tipc_max_zones; z_num++) { 157 if (tipc_net.zones[z_num]) 158 tipc_zone_send_external_routes(tipc_net.zones[z_num], dest); 159 } 160 } 161 162 static void net_stop(void) 163 { 164 u32 z_num; 165 166 for (z_num = 1; z_num <= tipc_max_zones; z_num++) 167 tipc_zone_delete(tipc_net.zones[z_num]); 168 } 169 170 static void net_route_named_msg(struct sk_buff *buf) 171 { 172 struct tipc_msg *msg = buf_msg(buf); 173 u32 dnode; 174 u32 dport; 175 176 if (!msg_named(msg)) { 177 msg_dbg(msg, "tipc_net->drop_nam:"); 178 buf_discard(buf); 179 return; 180 } 181 182 dnode = addr_domain(msg_lookup_scope(msg)); 183 dport = tipc_nametbl_translate(msg_nametype(msg), msg_nameinst(msg), &dnode); 184 dbg("tipc_net->lookup<%u,%u>-><%u,%x>\n", 185 msg_nametype(msg), msg_nameinst(msg), dport, dnode); 186 if (dport) { 187 msg_set_destnode(msg, dnode); 188 msg_set_destport(msg, dport); 189 tipc_net_route_msg(buf); 190 return; 191 } 192 msg_dbg(msg, "tipc_net->rej:NO NAME: "); 193 tipc_reject_msg(buf, TIPC_ERR_NO_NAME); 194 } 195 196 void tipc_net_route_msg(struct sk_buff *buf) 197 { 198 struct tipc_msg *msg; 199 u32 dnode; 200 201 if (!buf) 202 return; 203 msg = buf_msg(buf); 204 205 msg_incr_reroute_cnt(msg); 206 if (msg_reroute_cnt(msg) > 6) { 207 if (msg_errcode(msg)) { 208 msg_dbg(msg, "NET>DISC>:"); 209 buf_discard(buf); 210 } else { 211 msg_dbg(msg, "NET>REJ>:"); 212 tipc_reject_msg(buf, msg_destport(msg) ? 213 TIPC_ERR_NO_PORT : TIPC_ERR_NO_NAME); 214 } 215 return; 216 } 217 218 msg_dbg(msg, "tipc_net->rout: "); 219 220 /* Handle message for this node */ 221 dnode = msg_short(msg) ? tipc_own_addr : msg_destnode(msg); 222 if (tipc_in_scope(dnode, tipc_own_addr)) { 223 if (msg_isdata(msg)) { 224 if (msg_mcast(msg)) 225 tipc_port_recv_mcast(buf, NULL); 226 else if (msg_destport(msg)) 227 tipc_port_recv_msg(buf); 228 else 229 net_route_named_msg(buf); 230 return; 231 } 232 switch (msg_user(msg)) { 233 case ROUTE_DISTRIBUTOR: 234 tipc_cltr_recv_routing_table(buf); 235 break; 236 case NAME_DISTRIBUTOR: 237 tipc_named_recv(buf); 238 break; 239 case CONN_MANAGER: 240 tipc_port_recv_proto_msg(buf); 241 break; 242 default: 243 msg_dbg(msg,"DROP/NET/<REC<"); 244 buf_discard(buf); 245 } 246 return; 247 } 248 249 /* Handle message for another node */ 250 msg_dbg(msg, "NET>SEND>: "); 251 tipc_link_send(buf, dnode, msg_link_selector(msg)); 252 } 253 254 int tipc_net_start(u32 addr) 255 { 256 char addr_string[16]; 257 int res; 258 259 if (tipc_mode != TIPC_NODE_MODE) 260 return -ENOPROTOOPT; 261 262 tipc_subscr_stop(); 263 tipc_cfg_stop(); 264 265 tipc_own_addr = addr; 266 tipc_mode = TIPC_NET_MODE; 267 tipc_named_reinit(); 268 tipc_port_reinit(); 269 270 if ((res = tipc_cltr_init()) || 271 (res = tipc_bclink_init())) { 272 return res; 273 } 274 275 tipc_k_signal((Handler)tipc_subscr_start, 0); 276 tipc_k_signal((Handler)tipc_cfg_init, 0); 277 278 info("Started in network mode\n"); 279 info("Own node address %s, network identity %u\n", 280 tipc_addr_string_fill(addr_string, tipc_own_addr), tipc_net_id); 281 return 0; 282 } 283 284 void tipc_net_stop(void) 285 { 286 if (tipc_mode != TIPC_NET_MODE) 287 return; 288 write_lock_bh(&tipc_net_lock); 289 tipc_bearer_stop(); 290 tipc_mode = TIPC_NODE_MODE; 291 tipc_bclink_stop(); 292 net_stop(); 293 write_unlock_bh(&tipc_net_lock); 294 info("Left network mode\n"); 295 } 296 297