Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 1 | /* |
| 2 | * net/tipc/net.c: TIPC network routing code |
| 3 | * |
Per Liden | 593a5f2 | 2006-01-11 19:14:19 +0100 | [diff] [blame] | 4 | * Copyright (c) 1995-2006, Ericsson AB |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 5 | * Copyright (c) 2005, Wind River Systems |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 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 | * |
Per Liden | 9ea1fd3 | 2006-01-11 13:30:43 +0100 | [diff] [blame] | 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. |
Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 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, 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 net_lock and other protective locks. |
| 67 | * |
| 68 | * Within the 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 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 | * net_lock(read), protected by an individual spin_lock ber bearer |
| 79 | * instance, but it needs 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 (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 (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 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 nametbl_lock(read). |
| 115 | * - A local spin_lock protecting the queue of subscriber events. |
| 116 | */ |
| 117 | |
| 118 | rwlock_t net_lock = RW_LOCK_UNLOCKED; |
| 119 | struct network net = { 0 }; |
| 120 | |
| 121 | struct node *net_select_remote_node(u32 addr, u32 ref) |
| 122 | { |
| 123 | return zone_select_remote_node(net.zones[tipc_zone(addr)], addr, ref); |
| 124 | } |
| 125 | |
| 126 | u32 net_select_router(u32 addr, u32 ref) |
| 127 | { |
| 128 | return zone_select_router(net.zones[tipc_zone(addr)], addr, ref); |
| 129 | } |
| 130 | |
| 131 | |
| 132 | u32 net_next_node(u32 a) |
| 133 | { |
| 134 | if (net.zones[tipc_zone(a)]) |
| 135 | return zone_next_node(a); |
| 136 | return 0; |
| 137 | } |
| 138 | |
| 139 | void net_remove_as_router(u32 router) |
| 140 | { |
| 141 | u32 z_num; |
| 142 | |
| 143 | for (z_num = 1; z_num <= tipc_max_zones; z_num++) { |
| 144 | if (!net.zones[z_num]) |
| 145 | continue; |
| 146 | zone_remove_as_router(net.zones[z_num], router); |
| 147 | } |
| 148 | } |
| 149 | |
| 150 | void net_send_external_routes(u32 dest) |
| 151 | { |
| 152 | u32 z_num; |
| 153 | |
| 154 | for (z_num = 1; z_num <= tipc_max_zones; z_num++) { |
| 155 | if (net.zones[z_num]) |
| 156 | zone_send_external_routes(net.zones[z_num], dest); |
| 157 | } |
| 158 | } |
| 159 | |
| 160 | int net_init(void) |
| 161 | { |
| 162 | u32 sz = sizeof(struct _zone *) * (tipc_max_zones + 1); |
| 163 | |
| 164 | memset(&net, 0, sizeof(net)); |
| 165 | net.zones = (struct _zone **)kmalloc(sz, GFP_ATOMIC); |
| 166 | if (!net.zones) { |
| 167 | return -ENOMEM; |
| 168 | } |
| 169 | memset(net.zones, 0, sz); |
| 170 | return TIPC_OK; |
| 171 | } |
| 172 | |
| 173 | void net_stop(void) |
| 174 | { |
| 175 | u32 z_num; |
| 176 | |
| 177 | if (!net.zones) |
| 178 | return; |
| 179 | |
| 180 | for (z_num = 1; z_num <= tipc_max_zones; z_num++) { |
| 181 | zone_delete(net.zones[z_num]); |
| 182 | } |
| 183 | kfree(net.zones); |
| 184 | net.zones = 0; |
| 185 | } |
| 186 | |
| 187 | static void net_route_named_msg(struct sk_buff *buf) |
| 188 | { |
| 189 | struct tipc_msg *msg = buf_msg(buf); |
| 190 | u32 dnode; |
| 191 | u32 dport; |
| 192 | |
| 193 | if (!msg_named(msg)) { |
| 194 | msg_dbg(msg, "net->drop_nam:"); |
| 195 | buf_discard(buf); |
| 196 | return; |
| 197 | } |
| 198 | |
| 199 | dnode = addr_domain(msg_lookup_scope(msg)); |
| 200 | dport = nametbl_translate(msg_nametype(msg), msg_nameinst(msg), &dnode); |
| 201 | dbg("net->lookup<%u,%u>-><%u,%x>\n", |
| 202 | msg_nametype(msg), msg_nameinst(msg), dport, dnode); |
| 203 | if (dport) { |
| 204 | msg_set_destnode(msg, dnode); |
| 205 | msg_set_destport(msg, dport); |
| 206 | net_route_msg(buf); |
| 207 | return; |
| 208 | } |
| 209 | msg_dbg(msg, "net->rej:NO NAME: "); |
| 210 | tipc_reject_msg(buf, TIPC_ERR_NO_NAME); |
| 211 | } |
| 212 | |
| 213 | void net_route_msg(struct sk_buff *buf) |
| 214 | { |
| 215 | struct tipc_msg *msg; |
| 216 | u32 dnode; |
| 217 | |
| 218 | if (!buf) |
| 219 | return; |
| 220 | msg = buf_msg(buf); |
| 221 | |
| 222 | msg_incr_reroute_cnt(msg); |
| 223 | if (msg_reroute_cnt(msg) > 6) { |
| 224 | if (msg_errcode(msg)) { |
| 225 | msg_dbg(msg, "NET>DISC>:"); |
| 226 | buf_discard(buf); |
| 227 | } else { |
| 228 | msg_dbg(msg, "NET>REJ>:"); |
| 229 | tipc_reject_msg(buf, msg_destport(msg) ? |
| 230 | TIPC_ERR_NO_PORT : TIPC_ERR_NO_NAME); |
| 231 | } |
| 232 | return; |
| 233 | } |
| 234 | |
| 235 | msg_dbg(msg, "net->rout: "); |
| 236 | |
| 237 | /* Handle message for this node */ |
| 238 | dnode = msg_short(msg) ? tipc_own_addr : msg_destnode(msg); |
| 239 | if (in_scope(dnode, tipc_own_addr)) { |
| 240 | if (msg_isdata(msg)) { |
| 241 | if (msg_mcast(msg)) |
| 242 | port_recv_mcast(buf, NULL); |
| 243 | else if (msg_destport(msg)) |
| 244 | port_recv_msg(buf); |
| 245 | else |
| 246 | net_route_named_msg(buf); |
| 247 | return; |
| 248 | } |
| 249 | switch (msg_user(msg)) { |
| 250 | case ROUTE_DISTRIBUTOR: |
| 251 | cluster_recv_routing_table(buf); |
| 252 | break; |
| 253 | case NAME_DISTRIBUTOR: |
| 254 | named_recv(buf); |
| 255 | break; |
| 256 | case CONN_MANAGER: |
| 257 | port_recv_proto_msg(buf); |
| 258 | break; |
| 259 | default: |
| 260 | msg_dbg(msg,"DROP/NET/<REC<"); |
| 261 | buf_discard(buf); |
| 262 | } |
| 263 | return; |
| 264 | } |
| 265 | |
| 266 | /* Handle message for another node */ |
| 267 | msg_dbg(msg, "NET>SEND>: "); |
| 268 | link_send(buf, dnode, msg_link_selector(msg)); |
| 269 | } |
| 270 | |
| 271 | int tipc_start_net(void) |
| 272 | { |
| 273 | char addr_string[16]; |
| 274 | int res; |
| 275 | |
| 276 | if (tipc_mode != TIPC_NODE_MODE) |
| 277 | return -ENOPROTOOPT; |
| 278 | |
| 279 | tipc_mode = TIPC_NET_MODE; |
| 280 | named_reinit(); |
| 281 | port_reinit(); |
| 282 | |
| 283 | if ((res = bearer_init()) || |
| 284 | (res = net_init()) || |
| 285 | (res = cluster_init()) || |
| 286 | (res = bclink_init())) { |
| 287 | return res; |
| 288 | } |
| 289 | subscr_stop(); |
| 290 | cfg_stop(); |
| 291 | k_signal((Handler)subscr_start, 0); |
| 292 | k_signal((Handler)cfg_init, 0); |
| 293 | info("Started in network mode\n"); |
| 294 | info("Own node address %s, network identity %u\n", |
| 295 | addr_string_fill(addr_string, tipc_own_addr), tipc_net_id); |
| 296 | return TIPC_OK; |
| 297 | } |
| 298 | |
| 299 | void tipc_stop_net(void) |
| 300 | { |
| 301 | if (tipc_mode != TIPC_NET_MODE) |
| 302 | return; |
| 303 | write_lock_bh(&net_lock); |
| 304 | bearer_stop(); |
| 305 | tipc_mode = TIPC_NODE_MODE; |
| 306 | bclink_stop(); |
| 307 | net_stop(); |
| 308 | write_unlock_bh(&net_lock); |
| 309 | info("Left network mode \n"); |
| 310 | } |
| 311 | |